ArticlePDF Available

Abstract and Figures

Background: Ketogenic diets (KD) have become a popular method of promoting weight loss. More recently, some have recommended that athletes adhere to ketogenic diets in order to optimize changes in body composition during training. This study evaluated the efficacy of an 8-week ketogenic diet (KD) during energy surplus and resistance training (RT) protocol on body composition in trained men. Methods: Twenty-four healthy men (age 30 ± 4.7 years; weight 76.7 ± 8.2 kg; height 174.3 ± 19.7 cm) performed an 8-week RT program. Participants were randomly assigned to a KD group (n = 9), non-KD group (n = 10, NKD), and control group (n = 5, CG) in hyperenergetic condition. Body composition changes were measured by dual energy X-ray absorptiometry (DXA). Compliance with the ketosis state was monitored by measuring urinary ketones weekly. Data were analyzed using a univariate, multivariate and repeated measures general linear model (GLM) statistics. Results: There was a significant reduction in fat mass (mean change, 95% CI; p-value; Cohen's d effect size [ES]; - 0.8 [- 1.6, - 0.1] kg; p < 0.05; ES = - 0.46) and visceral adipose tissue (- 96.5 [- 159.0, - 34.0] g; p < 0.05; ES = - 0.84), while no significant changes were observed in the NKD and CG in fat mass (- 0,5 [- 1.2, 0.3] kg; p > 0.05; ES = - 0.17 and - 0,5 [- 2.4, 1.3] kg; p > 0.05; ES = - 0.12, respectively) or visceral adipose tissue (- 33.8 [- 90.4, 22.8]; p > 0.5; ES = - 0.17 and 1.7 [- 133.3, 136.7]; p > 0.05; ES = 0.01, respectively). No significant increases were observed in total body weight (- 0.9 [- 2.3, 0.6]; p > 0.05; ES = [- 0.18]) and muscle mass (- 0.1 [- 1.1,1.0]; p > 0,05; ES = - 0.04) in the KD group, but the NKD group showed increases in these parameters (0.9 [0.3, 1.5] kg; p < 0.05; ES = 0.18 and (1.3[0.5, 2.2] kg; p < 0,05; ES = 0.31, respectively). There were no changes neither in total body weight nor lean body mass (0.3 [- 1.2, 1.9]; p > 0.05; ES = 0.05 and 0.8 [- 0.4, 2.1]; p > 0.05; ES = 0.26, respectively) in the CG. Conclusion: Our results suggest that a KD might be an alternative dietary approach to decrease fat mass and visceral adipose tissue without decreasing lean body mass; however, it might not be useful to increase muscle mass during positive energy balance in men undergoing RT for 8 weeks.
Content may be subject to copyright.
R E S E A R C H A R T I C L E Open Access
Efficacy of ketogenic diet on body
composition during resistance training in
trained men: a randomized controlled trial
Salvador Vargas
, Ramón Romance
, Jorge L. Petro
, Diego A. Bonilla
, Ismael Galancho
, Sergio Espinar
Richard B. Kreider
and Javier Benítez-Porres
Background: Ketogenic diets (KD) have become a popular method of promoting weight loss. More recently, some
have recommended that athletes adhere to ketogenic diets in order to optimize changes in body composition
during training. This study evaluated the efficacy of an 8-week ketogenic diet (KD) during energy surplus and
resistance training (RT) protocol on body composition in trained men.
Methods: Twenty-four healthy men (age 30 ± 4.7 years; weight 76.7 ± 8.2 kg; height 174.3 ± 19.7 cm) performed an
8-week RT program. Participants were randomly assigned to a KD group (n= 9), non-KD group (n= 10, NKD), and
control group (n= 5, CG) in hyperenergetic condition. Body composition changes were measured by dual energy
X-ray absorptiometry (DXA). Compliance with the ketosis state was monitored by measuring urinary ketones weekly.
Data were analyzed using a univariate, multivariate and repeated measures general linear model (GLM) statistics.
Results: There was a significant reduction in fat mass (mean change, 95% CI; p-value; Cohens d effect size [ES];
0.8 [1.6, 0.1] kg; p< 0.05; ES = 0.46) and visceral adipose tissue (96.5 [159.0, 34.0] g; p< 0.05; ES = 0.84),
while no significant changes were observed in the NKD and CG in fat mass (0,5 [1.2, 0.3] kg; p> 0.05; ES = 0.17
and 0,5 [2.4, 1.3] kg; p> 0.05; ES = 0.12, respectively) or visceral adipose tissue (33.8 [90.4, 22.8]; p> 0.5; ES =
0.17 and 1.7 [133.3, 136.7]; p> 0.05; ES = 0.01, respectively). No significant increases were observed in total body
weight (0.9 [2.3, 0.6]; p> 0.05; ES = [0.18]) and muscle mass (0.1 [1.1,1.0]; p> 0,05; ES = 0.04) in the KD
group, but the NKD group showed increases in these parameters (0.9 [0.3, 1.5] kg; p< 0.05; ES = 0.18 and (1.3[0.5,
2.2] kg; p< 0,05; ES = 0.31, respectively). There were no changes neither in total body weight nor lean body mass
(0.3 [1.2, 1.9]; p> 0.05; ES = 0.05 and 0.8 [0.4, 2.1]; p>0.05; ES = 0.26, respectively) in the CG.
Conclusion: Our results suggest that a KD might be an alternative dietary approach to decrease fat mass and
visceral adipose tissue without decreasing lean body mass; however, it might not be useful to increase muscle mass
during positive energy balance in men undergoing RT for 8 weeks.
Keywords: Hypertrophy, Ketosis, High-fat diet, Fat distribution, Bodybuilding
* Correspondence:
EADE-University of Wales Trinity Saint David, Málaga, Spain
Human Kinetics and Body Composition Laboratory, Faculty of Education
Sciences, University of Málaga, Málaga, Spain
Full list of author information is available at the end of the article
© The Author(s). 2018 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0
International License (, which permits unrestricted use, distribution, and
reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to
the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver
( applies to the data made available in this article, unless otherwise stated.
Vargas et al. Journal of the International Society of Sports Nutrition (2018) 15:31
Macronutrient manipulation has become a key nutrition
component that, implemented in synergy with training,
seeks to improve physical appearance, performance and
human health. Among many dietary strategies that have
been adopted, ketogenic diet (KD) is a subtype of low-
carbohydrate and high-fat diet that needs to be planned
considering special dietary features (such as the propor-
tion of macronutrients) and physiological changes (ketosis
generation). In view of the foregoing, KD should be
planned from an objective perspective, checking for any
increase in circulating ketone bodies (KB), a distinctive
marker of physiological/nutritional ketosis. Main KB
(acetate, acetone, and β-hydroxybutyrate) are produced in
the liver under low-carbohydrate availability conditions,
acting as an alternative energy source for peripheral tissue,
such as skeletal muscle, brain and heart [1]. To achieve a
state of ketosis through a KD, carbohydrate intake should
be reduced to a maximum of around 50 g per day, or 10%
of total caloric intake during the day, while protein intake
is moderate or high (e.g. 1.2 to 1.5 gkg
Remaining energy intake is predominantly from fats (60
to 80%), depending on the degree of displacement of car-
bohydrates and proteins [2].
Under normal conditions (with no KD diet or long
fasting periods), the circulating KB values (β-hydroxybu-
tyrate being the primary KB) are very low (<3 mmolL
); however, during physiological ketosis, as a result of
the KD, ketonemia can reach maximum levels of 7
8 mmolL
with no significant changes in blood pH [3].
At this point, it is important to clarify the difference be-
tween physiological ketosis and diabetic ketoacidosis,
where the concentration of KB in the blood can exceed
20 mmolL
, with a significant reduction in blood pH.
In healthy population, the circulating KB values do not
exceed 8 mmolL
, because the central nervous sys-
tem uses these molecules efficiently as a source of en-
ergy, instead of glucose [4].
Several studies have focused on the effects of KDs on
reducing body mass [5,6], on improving health condi-
tions, or as part of managing certain pathologies such as
type 2 diabetes mellitus [7,8], nervous system disorders
such as epilepsy [911], and in different types/stages of
cancer [1216]. Currently, there is some controversy
surrounding the advantages or disadvantages of KD for
sports performance. It has been argued, on the one
hand, that there are beneficial effects associated with the
reduction of total body mass and body fat, a higher rate
of fat oxidation, lower glucose oxidation and a reduction
in the rate of muscle glycogen utilization during physical
exertion, which represents an advantage in resistance
exercise [17]. On the other hand, physiological mecha-
nisms have been cited that may limit performance in re-
sistance training due to central fatigue, possibly because
of increased circulation of non-esterified fatty acids
which increases competition between these and trypto-
phan for albumin, resulting in an increase in free
tryptophan, which in turn causes a greater absorption by the
brain and subsequent augmentation of 5-hydroxytryptamine
(serotonin) synthesis, a neurotransmitter linked to the feel-
ing of lethargy and tiredness that may contribute to nerve
signal losses at central level and a decrease in motivation. In
addition, greater oxidation of amino acids can occur, which
increases the concentration of ammonia, contributing to
central fatigue [17]. In general, several authors have also
established that low-carbohydrate diets or KD do not seem
to be superior or offer advantages for resistance exercise,
compared with carbohydrate-rich diets [18,19].
With regards to the effects of KD combined with re-
sistance training (RT), such as muscle hypertrophy, there
is even less information available, when compared with
studies conducted on endurance-type performance. Even
though KD can provide adequate quantities of proteins
and calories necessary for muscle-protein synthesis in-
duced by RT, they induce a state similar to fasting,
prompting alterations in the metabolic pathways and
molecular processes relating to autophagy and stress re-
sistance [20], which consequently might hinder the
building of muscle mass.
Considering the need to study on the effects of KD in
resistance-trained subjects, the purpose of this study was
to determine if following a KD hypercaloric diet would
promote greater gains in fat free mass and fat loss dur-
ing a hypertrophic training period in resistance-trained
men. We hypothesized that a KD with caloric surplus in
combination with RT in trained men would have a posi-
tive impact in fat reduction, and it would benefit the
gains in lean body mass (LBM).
Study design
This study was conducted as a randomized, parallel arm,
controlled, prospective study. The independent variable
was nutritional intervention. The primary outcome vari-
ables were changes in body composition.
Figure 1presents a CONSORT diagram. Twenty-four
healthy men with more than 2 years of continuous ex-
perience in overload training participated in this
randomized controlled study (age = 30 ± 4.5 years;
height = 177 ± 3.4 cm; weight = 76.7 ± 5.7 kg; BMI = 23.4
± 2.2 kg/m
). All volunteered their participation and
agreed to complete the supervised training and diet pro-
tocols during the 8 weeks of the study. Subjects who had
consumed androgenic-anabolic steroids during the last 2
years or those who consumed any type of dietary supple-
ment during the study were excluded. The subjects were
Vargas et al. Journal of the International Society of Sports Nutrition (2018) 15:31 Page 2 of 9
advised of the potential risks of the experiment and
signed an informed consent form. The study was devel-
oped following the ethical guidelines of the Declaration
of Helsinki [21]. The investigation was developed in
Málaga (Spain). The first evaluation took place on
February 2017 and the second measurement on April of
the same year.
Body composition
Total and regional body composition were estimated
using a Hologic QDR 4500 dual-energy x-ray absorpti-
ometry (DXA) scanner (Hologic Inc., Bedford, MA,
USA). Each subject was scanned by a certified techni-
cian, and the distinguished bone and soft tissue, edge
detection, and regional demarcations were done by com-
puter algorithms with APEX Software 3.0 (APEX
Corporation Software, Pittsburg, PA, USA). For each
scan, subjects wore sport clothes and were asked to re-
move all materials that could attenuate the X-ray beam,
including jewelry items. Calibration of the densitometer
was checked daily against standard calibration block
supplied by the manufacturer.
Abdominal region was delineated by an upper hori-
zontal border located at half of the distance between
acromions and external end of iliac crests, a lower
border determined by the external end of iliac crests,
and the lateral borders extending to the edge of the
abdominal soft tissue. All trunk tissue within this stan-
dardized height region was selected for analysis. To de-
termine intertester reliability, two different observers
selected the area for each subject manually.
Nutrition intervention
The participants were randomly assigned to a KD group
(n= 9), non-KD (NKD) (n= 10) group, and control group
(CG) (n= 5). Compliance with the ketosis state was moni-
tored by measuring urinary ketones weekly using reagent
strips (Ketostix, Bayer Vital GmbH, Leverkusen, Germany),
from week two to the end of the study in KD group.
Under the supervision of a registered dietitian, the sub-
jects were given a detailed questionnaire about their work
and sociocultural activities, as well as dietary preferences
in order to estimate the basal metabolic rate and physical
activity-related energy expenditure. Subjects were classi-
fied as active in their day-to-day lives, estimating total en-
ergy expenditure in line with the indications [22]. Once
energy expenditure was determined, together with their
weekly training load, a moderate energy surplus was
established for experimental groups, since it has been
noted that trained men do not require energy increases as
high as novice subjects [23,24]. To guarantee a hyperener-
getic condition, a daily energy intake of 39 kcal·kg
was used in all subjects. To ensure a maximal anabolic
response, NKD group was given a protein intake of 2
, as it is recommended for building muscle
mass in trained subjects [2,22,25], while 25% of
total energy intake corresponded to fat and the
remaining calories were given in carbohydrates.
Macronutrient distribution for NKD group was about 55%
CHO; 20% PRO and 25% FAT. On the other hand, 42 g
total carbohydrates per day were administered to KD
group to ensure the ketosis state [26,27]. Protein intake
was 2 gkg
, and the remaining calories were given
in fat with a estimating of 3.2 gkg
distribution for KD group was about <10% CHO; 20%
PRO and 70% FAT. Ad libitum meal timing and frequency
throughout the day was allowed to improve dietary adher-
ence. Even though a specific number of meals per day is
not necessary, provided the daily energy intake is guaran-
teed [22], from 3 to 6 meals were recommended, with the
respective foods selected for the KD group.
Training protocol
During 8 weeks both KD and NKD groups completed
four sessions per week of a hypertrophy training proto-
col, organized into a 2-days upper- and 2-days
lower-limb, with 72 h of rest between sessions to en-
courage recovery [28] (Fig. 2).
Participants were experienced in overload training and
used to different nutritional strategies; therefore, no
familiarization session was necessary. Moderate to high
loads were used to encourage mechanical tension [29].
Rest between sets lasted 3 min, so that volume did not
decline [30,31]. Cadences were explosive in the concen-
tric activation, and 3 s long during the eccentric contrac-
tion to generate more muscle damage [29,32]. Two
weekly stimuli were provided for each muscle group in
order to optimize the final results [33]. Push and pull
exercises were interspersed for better recovery [34]. Sub-
jects from both groups were asked to increase loads as
long as they exceeded repetition rates and had no error
technique. During the intervention, all participants were
Fig. 1 CONSORT diagram
Vargas et al. Journal of the International Society of Sports Nutrition (2018) 15:31 Page 3 of 9
monitored by an RT specialist who supervised and
checked the load at each training session, and made the
relevant adjustments when was necessary. Meanwhile,
men in control group were asked to maintain their
current level of physical activity during the study.
Statistical analysis
Descriptive statistics tests were applied (mean and
standard deviation, SD). Data were analyzed using a uni-
variate, multivariate and repeated measures general lin-
ear model (GLM), with two levels by time (pre- and
post-test) and considering groups (KD, NKD and CG) as
inter-subjects factor. WilksLambda multivariate tests
are reported to describe overall effects of related vari-
ables analyzed. Greenhouse-Geisser univariate tests with
least significant difference and post-hoc comparisons
(Bonferroni correction) are presented for individual
variables analyzed. Partial eta squared effect sizes (ηp
were also reported on select variables as an indicator of
effect size (ES) of the repeated measures GLM. An Eta
squared around 0.02 was considered small, 0.13 medium,
and 0.26 large [35]. Furthermore, one-way analysis of
variance (ANOVA), with a 95.0% confidence level and
Bonferroni post-hoc correction, as is recommended for
these studies [36,37], was performed to detect
between-group differences in the Δchanges (post-test
pre-test). In addition, ES calculation was done with
Cohensd, as a standardized measurement based on SD
differences; while d = 0.2 was considered a small effect,
d = 0.5 was a medium effect and d = 0.8 was a large ef-
fect, which is used as a guide for substantive signifi-
cance. The normal Gaussian distribution of the data was
verified by the Shapiro-Wilk test. Mean changes with
95% CIs completely above or below baseline are consid-
ered significant changes from baseline. These statistical
analyses were performed with licensed Statistical Pack-
age for the Social Sciences (SPSS) software (SPSS 24.0,
SPSS Inc., Chicago, USA) and GraphPad software
(GraphPad Prism 7.03, California, USA).
Baseline characteristics
A total number of 26 individuals met initial screening
criteria and consented to participate in the study (Fig. 1).
Two participants did not enter into ketosis state and
were excluded from the study, which left nine men for
analysis in KD group. Statistical analyses were performed
on 24 individuals. Descriptive statistics with baseline
characteristics are summarized, by groups in Table 1.
Body composition
The statistical results before and after the intervention
for total body weight (BW) and body composition; fat
mass (FM), visceral adipose tissue (VAT), and LBM are
shown in Table 2. Multivariate analysis showed signifi-
cant overall WilksLambda in time interaction (p=
Fig. 2 Overview of training protocol. WK: Workout (microcycle); UL: Upper-Limb; LL: Lower-Limb; R: Rest; 30X: 3 s of eccentric contraction and
explosive movement during concentric activity
Vargas et al. Journal of the International Society of Sports Nutrition (2018) 15:31 Page 4 of 9
0.031; with a large effect size, ηp
= 0.36) and in time x
group (p< 0.05; with a large effect size, ηp
= 0.264). On
the other hand, univariate analysis revealed significant
differences in time x group interaction between BW, and
LBM (p< 0.05), with a large effect size for BW (ηp
0.36); however, no significant differences were found in
VAT. Significant differences were observed over time in
VAT and LBM, with medium effect size for both (ηp
0.20 and 0.23, respectively). No significant differences
were found after group interaction analysis of the study
According to the results by group, BW increased in
KD group (p< 0.05), but to a small size (ES = 0.18), with
no significant differences in the other groups (NKD and
CG). With regards to FM, only KD group showed a sig-
nificant reduction (p< 0.05), expressing a medium effect
(ES = 0.46). Similarly, VAT only decreased markedly in
the KD group (p< 0.05), showing a considered large
effect (ES = 0.84). Conversely, LBM showed a highly
significant increase (p< 0.05) with moderate effect (ES =
0.31) in the NKD group; however, although LBM de-
creased in the KD group, this did not represent a statis-
tically significant difference or significant effect (p> 0.05;
ES = 0.04).
These results suggest that KD group achieved a posi-
tive change in body composition, due to a decrease in
BW (0.9 [2.3, 0.6] kg; p> 0.05) with a reduction in
FM (0.8 [1.6, 0.1] kg; p< 0.05) and accompanied by
a notably lower VAT (96.5 [159.0, 34.0] g; p< 0.05).
Regarding to LBM, an adequate carbohydrate intake
(non-ketogenic or conventional dietary approach), in
conjunction with a caloric surplus and a higher protein
intake, might be the most viable option for inducing
muscle hypertrophy after RT. This last was shown in this
study, where there was an increase in LBM (1.3 [0.5, 2.2]
kg; p< 0.05) in the NKD group, leading to an increase in
BW (0.9 [2.3, 0.6] kg; p< 0.05). Figure 3shows sig-
nificant differences in BW and LBM for NKD group;
and FM and VAT for KD group. Likewise, post-hoc ana-
lysis showed significant difference in the BW and LBM
between KD and NDK groups.
The aim of this study was to determine the efficacy of
the KD when combined with an RT program on body
composition in trained subjects over a period of 8 weeks
of intervention.
We originally hypothesized that this intervention
would improve body composition due to a greater re-
duction in FM and VAT, and an increase in LBM. Our
hypothesis is supported by some lines of evidence, but
there are contradictory findings due to a lack of studies
analyzing the effects of the KD (with and without RT
protocol) on FM, VAT and muscle hypertrophy. Human
Table 1 Characteristics of participants at baseline
CG KD NKD p-value
Age (years) 31.6 ± 4.6 27.6 ± 4.2 27.1 ± 5.6 0.276
Height (cm) 179.9 ± 7.8 178.3 ± 4.0 178.3 ± 6.2 0.873
BW (kg) 78.9 ± 6.5 78.8 ± 7.8 74.6 ± 5.3 0.306
BMI (kgm
) 24.5 ± 1.7 24.4 ± 2.6 23.9 ± 1.6 0.793
FM (kg) 13.4 ± 4.5 12.0 ± 2.7 11.3 ± 2.6 0.499
LBM (kg) 65.6 ± 2.6 66.8 ± 6.8 63.2 ± 4.4 0.350
VAT (g) 757.7 ± 265.3 688.9 ± 125.4 658.0 ± 200.5 0.650
Data are means ± SD; p< 0.05 is considered significant; BW Total body weight,
BMI Body Mass Index, FM Fat mass, LBM Lean body mass, VAT Visceral
adipose tissue
Table 2 Results before and after the intervention for body composition by groups
Pre Post ES Interaction p-value (ηp
(Mean ± SD) (Mean ± SD)
BW CG 78.9 ± 6.5 79.2 ± 6.6 0.05 Time 0.830 (0.002)
KD 78.8 ± 7.8 77.4 ± 7.9 0.18 Group 0.437 (0.076)
NDK 74.6 ± 5.3 75.5 ± 4.9* 0.18 Time x Group 0.016 (0.327)
FM CG 13.4 ± 4.5 12.8 ± 4.0 0.12 Time 0.013 (0.258)
KD 12.0 ± 2.7 10.9 ± 2.2* 0.46 Group 0.457 (0.072)
NDK 11.3 ± 2.6 10.9 ± 2.7 0.17 Time x Group 0.447 (0.074)
VAT CG 757.7 ± 265.3 759.4 ± 317.2 0.01 Time 0.031 (0.203)
KD 688.9 ± 125.4 592.4 ± 103.1* 0.84 Group 0.490 (0.066)
NDK 658.0 ± 200.5 624.2 ± 201.5 0.17 Time x Group 0.130 (0.177)
LBM CG 65.6 ± 2.6 66.4 ± 3.5 0.26 Time 0.023 (0.224)
KD 66.8 ± 6.8 66.5 ± 6.9 0.04 Group 0.516 (0.061)
NDK 63.2 ± 4.4 64.6 ± 4.2* 0.31 Time x Group 0.025 (0.297)
Data are means ± SD; Greenhouse-Geisser univariate p-levels are presented for each variable; p< 0.05 is considered significant; (*) denotes a significant difference
from baseline; ES Effect Size (Cohens d), BW Total body weight, FM Fat mass, VAT Visceral adipose tissue, LBM lean body mass
Vargas et al. Journal of the International Society of Sports Nutrition (2018) 15:31 Page 5 of 9
studies have reported a reduction in FM during and after
KD, but with a concomitant loss of of LBM [3844]. For
example, Gomez-Arbelaez [45], found that a low-calorie
KD (starting in the initial phases with 600800 kcal per
day and following the PNK® method) resulted in a de-
crease in VAT, according to a follow-up study performed
over 4 months. Notwithstanding, it should be noted that
these studies included obese subjects, in some cases with
at least one cardiovascular risk factor and, with no phys-
ical exercise intervention, strength training in particular.
In another study [46], there was a reduction in adipose
mass tissue and a parallel increase in LBM after per-
forming a variety of strength or resistance exercises in
moderately active subjects with normal weight; these
changes in body composition (especially FM reduction)
were attributed in part to a decrease in insulin concen-
trations. It is probable that the incorporation of RT,
together with moderate/high protein consumption and a
caloric surplus, may be an important strategy for main-
taining fat free mass during KD. In particular, RT alone,
or combined with endurance training, accompanied by a
hypoenergetic KD, might be useful for the preservation
of fat free mass and the increased metabolic rate in
obese subjects, as an intervention that deserves further
research, considering the complexity of this multifactor-
ial illness [47]. In fact, even though endurance exercise
is more effective than RT in reducing VAT [48], a com-
bination of endurance training and RT is more plausible
for improving body composition in this population [49].
Since few studies have evaluated the combined effect of
the KD and RT in trained subjects on VAT, our study
contributes to current literature by showing a significant
reduction in VAT after 8 weeks of KD in hyperenergetic
condition in resistance-trained men. These results sug-
gest that KD group achieved a positive change in body
composition, due to a decrease in BW (0.9 [2.3, 0.6]
kg; p> 0.05) with a reduction in FM (0.8 [1.6, 0.1]
kg; p< 0.05) and accompanied by a notably lower VAT
(96.5 [159.0, 34.0] g; p< 0.05). This supports the
need for in-depth analysis about the importance of
macronutrient distribution, comparing isoenergetic nu-
tritional programs, on the distribution of body fat.
On the other hand, animal studies on ketosis-induced
interventions after KD have not found neither acute nor
chronic changes in hypertrophic response in skeletal
muscle, when strength exercises were performed, in
comparison with a mixed diet of macronutrients [50];
however, a reduction in FM was observed in these ro-
dents [51]. Although these results were obtained in
animal models, it seems that these effects are similar but
not extrapolable to humans. Our study involved
resistance-trained young men with an RT program inter-
vention focused on mechanical tension to generate
changes in LBM, considering this as one of the main fac-
tors of RT-induced muscle hypertrophy [29,52,53].
Also, a 3 min-rest pause between sets and short time
under tension was considered, to discourage a dramatic
decrease in muscle glycogen. Subsequently, comparison
of changes in variables, by one-factor ANOVA, revealed
a difference between means in all groups regarding BW
and LBM; in fact, there was an increase in LBM (1.3
[0.5,2.2] kg; p< 0.05) in the NKD group, leading to an
increase in BW (0.9 [2.3, 0.6] kg; p< 0.05). Figure 3
shows significant differences in BW and LBM for NKD
group; and FM and VAT for KD group. Likewise,
post-hoc analysis showed significant difference in the
BW and LBM between KD and NDK groups. These re-
sults are in agreement with those obtained by Rauch et
al. [54], who compared the effects of a KD (5% CHO,
75% fat and 20% protein) with a traditional western diet
(55% CHO, 25% fat and 20% protein) in men undergoing
RT training (n= 26), during 11 weeks. These authors
also found a decrease in FM in the KD group but, unlike
our results, there was an increase in LBM.
The results of the present study are in accordance with
a significant reduction in FM and VAT in resistance-trained
men undergoing a KD while participating in a RT
Fig. 3 Changes in body mass and body composition. Mean changes
with 95% CIs completely above or below the baseline are significant
changes; BW: Total body weight; FM: Fat mass; VAT: Visceral adipose
tissue; LBM: lean body mass. aChanges in BW, FM, LBM. bChanges in
VAT. ǂSignificant difference with KD after post-hoc analysis (p<0.05)
Vargas et al. Journal of the International Society of Sports Nutrition (2018) 15:31 Page 6 of 9
program; however, no changes were seen in LBM in
this group. The clinical significance is the reduction in
VAT, which could have health benefit because of its in-
verse correlation to cardiometabolic disease [55,56].
Regarding to LBM, an adequate carbohydrate intake
(non-ketogenic or conventional dietary approach), in con-
junction with a caloric surplus and a higher protein intake,
might be the most viable option for inducing muscle
hypertrophy after RT.
This study has several limitations that should be men-
tioned. Firstly, this research only included body compos-
ition measurements and did not include blood measures.
In addition, limited outcome measurements, small num-
ber of subjects and intervention time (8 weeks) reduce
the impact of the study. On the other hand, dietary as-
sessment of appetite suppression by high-fat diet was
not performed. So, it is possible to have variations in en-
ergy intake even though participants were instructed to
follow specific dietary recommendations. Moreover,
since KD may affect negatively training volume, we
should consider integrating performance measurements
or load volume to see changes. In addition, rated
perceived exertion might give interesting information
about changes during KD adaptation and progression of
RT protocol.
According to our results, we concluded that subjects
who underwent RT during a KD experienced a greater
reduction in FM and VAT, when compared to the NKD
group. The greater reduction in VAT may have some
clinical relevance due to its inverse association to
cardio-metabolic risk. Further studies are necessary to
evaluate the advantages of this combination (RT and
KD) in subjects with excess of body FM, with particular
attention to the reported significant reduction in VAT,
which might be highly beneficial to this population given
that LBM is maintained. Indeed, this research showed
no significant changes nor effect size on LBM, despite
hyperenergetic condition and high protein intake
(2.0 gkg
) in resistance-trained men of the KD
group. Thus, we conclude that low-carbohydrate dietary
approaches, such as KD, would not be an optimum
strategy for building muscle mass in trained men under
the training conditions of this study (mechanical
tension-focused RT protocol during 8 weeks).
ANOVA: One-way analysis of variance; BMI: Body mass index; BW: Body
weight; CG: Control group; DXA: Dual-energy x-ray absorptiometry; ES: Effect
size; FM: Fat mass; KB: Ketogenic bodies; KD: Ketogenic diet; LBM: Lean body
mass; NKD: Non-ketogenic diet; RT: Resistance training; VAT: Visceral adipose
tissue; ηp
: Partial eta squared effect size
We are grateful to MSc. Kelly Salgado for her helpful statistics advice.
Supported by University of Málaga (Campus of International Excellence
Andalucía Tech).
Availability of data and materials
The datasets used and analyzed during the current study are available from
the corresponding author on reasonable request.
SV served as study coordinator. SV and IG conceived and designed the
experiments. JBP and RR served as lab coordinator and project manager for
the study coordination. SV, RR, and JBP assisted in data collection. SV, SE, and
IG designed the nutritional protocols. SV oversight nutrition and training. JLP
and RBK analyzed the data. JLP, RBK, JBP, and DAB assisted in analysis, and
manuscript review. SV, JLP, DAB and JBP wrote the paper. RBK assisted in the
statistics advice, discussion analysis, and manuscript preparation. All authors
read and approved the final manuscript.
Ethics approval and consent to participate
Participation in the study was voluntary, with written consent being
obtained from each subject before the initiation of data collection. This
study was conducted after review and approval by the Ethics Committee of
the EADE-University of Wales Trinity Saint David (Málaga, Spain). Committees
reference number: EADECAFYD2017-3.
Consent for publication
Not applicable.
Competing interests
The authors declare that they have no competing interests.
Springer Nature remains neutral with regard to jurisdictional claims in
published maps and institutional affiliations.
Author details
EADE-University of Wales Trinity Saint David, Málaga, Spain.
Human Kinetics
and Body Composition Laboratory, Faculty of Education Sciences, University
of Málaga, Málaga, Spain.
Research Group in Physical Activity, Sports and
Health Sciences, Universidad de Córdoba, Montería, Colombia.
of Biochemistry and Molecular Biology, Universidad Distrital Francisco José
de Caldas, Bogotá, Colombia.
BetterbyScience, Málaga, Spain.
Exercise &
Sport Nutrition Lab, Human Clinical Research Facility, Texas A&M University,
College Station, TX, USA.
Received: 8 March 2018 Accepted: 26 June 2018
1. Evans M, Cogan KE, Egan B. Metabolism of ketone bodies during exercise
and training: physiological basis for exogenous supplementation. J Physiol.
2. Aragon AA, Schoenfeld BJ, Wildman R, Kleiner S, VanDusseldorp T, Taylor L,
Earnest CP, Arciero PJ, Wilborn C, Kalman DS, et al. International society of
sports nutrition position stand: diets and body composition. J Int Soc Sports
Nutr. 2017;14:16.
3. Paoli A, Grimaldi K, Toniolo L, Canato M, Bianco A, Fratter A. Nutrition and
acne: therapeutic potential of ketogenic diets. Skin Pharmacol Physiol. 2012;
4. Paoli A. Ketogenic diet for obesity: friend or foe? Int J Environ Res Public
Health. 2014;11:2092107.
5. Bueno NB, de Melo IS, de Oliveira SL, da Rocha Ataide T. Very-low-
carbohydrate ketogenic diet v. Low-fat diet for long-term weight loss: a
meta-analysis of randomised controlled trials. Br J Nutr. 2013;110:117887.
6. Gibson AA, Sainsbury A. Strategies to improve adherence to dietary weight
loss interventions in research and real-world settings. Behav Sci (Basel).
Vargas et al. Journal of the International Society of Sports Nutrition (2018) 15:31 Page 7 of 9
7. Goday A, Bellido D, Sajoux I, Crujeiras AB, Burguera B, Garcia-Luna PP,
Oleaga A, Moreno B, Casanueva FF. Short-term safety, tolerability and
efficacy of a very low-calorie-ketogenic diet interventional weight loss
program versus hypocaloric diet in patients with type 2 diabetes mellitus.
Nutr Diab. 2016;6:e230.
8. Hussain TA, Mathew TC, Dashti AA, Asfar S, Al-Zaid N, Dashti HM. Effect of
low-calorie versus low-carbohydrate ketogenic diet in type 2 diabetes.
Nutrition. 2012;28:101621.
9. Youngson NA, Morris MJ, Ballard B. The mechanisms mediating the
antiepileptic effects of the ketogenic diet, and potential opportunities for
improvement with metabolism-altering drugs. Seizure. 2017;52:159.
10. Martin-McGill KJ, Jenkinson MD, Tudur Smith C, Marson AG. The modified
ketogenic diet for adults with refractory epilepsy: an evaluation of a set up
service. Seizure. 2017;52:16.
11. Martin K, Jackson CF, Levy RG, Cooper PN. Ketogenic diet and other dietary
treatments for epilepsy. Cochrane Database Syst Rev. 2016;2:Cd001903.
12. Klement RJ. Beneficial effects of ketogenic diets for cancer patients: a realist
review with focus on evidence and confirmation. Med Oncol. 2017;34:132.
13. Oliveira CL, Mattingly S, Schirrmacher R, Sawyer MB, Fine EJ, Prado CM. A
nutritional perspective of ketogenic diet in Cancer: a narrative review. J
Acad Nutr Diet. 2018;118:66888.
14. Erickson N, Boscheri A, Linke B, Huebner J. Systematic review: isocaloric
ketogenic dietary regimes for cancer patients. Med Oncol. 2017;34:72.
15. Smyl C. Ketogenic diet and Cancer-a perspective. Recent Results Cancer Res.
16. Walczyk T, Wick JY. The ketogenic diet: making a comeback. Consult Pharm.
17. Chang CK, Borer K, Lin PJ. Low-carbohydrate-high-fat diet: can it help
exercise performance? J Hum Kinet. 2017;56:8192.
18. Burke LM, Ross ML, Garvican-Lewis LA, Welvaert M, Heikura IA, Forbes SG,
Mirtschin JG, Cato LE, Strobel N, Sharma AP, Hawley JA. Low carbohydrate,
high fat diet impairs exercise economy and negates the performance
benefit from intensified training in elite race walkers. J Physiol. 2017;595:
19. Burke LM. Re-examining high-fat diets for sports performance: did we call
the Nail in the Coffintoo soon? Sports Med. 2015;45(Suppl 1):S3349.
20. Paoli A, Bianco A, Grimaldi KA. The ketogenic diet and sport: a possible
marriage? Exerc Sport Sci Rev. 2015;43:15362.
21. World Medical Association. Declaration of Helsinki: ethical principles for
medical research involving human subjects. J Am Coll Dent. 2014;81:148.
22. Helms E, Valdez A, Morgan A: The Muscle and Strength Pyramid: Nutrition. 2015.
23. Rozenek R, Ward P, Long S, Garhammer J. Effects of high-calorie
supplements on body composition and muscular strength following
resistance training. J Sports Med Phys Fitness. 2002;42:3407.
24. Garthe I, Raastad T, Refsnes PE, Sundgot-Borgen J. Effect of nutritional
intervention on body composition and performance in elite athletes. Eur J
Sport Sci. 2013;13:295303.
25. Jager R, Kerksick CM, Campbell BI, Cribb PJ, Wells SD, Skwiat TM, Purpura M,
Ziegenfuss TN, Ferrando AA, Arent SM, et al. International Society of Sports
Nutrition Position Stand: protein and exercise. J Int Soc Sports Nutr. 2017;14:20.
26. Hall KD, Chen KY, Guo J, Lam YY, Leibel RL, Mayer LE, Reitman ML,
Rosenbaum M, Smith SR, Walsh BT, Ravussin E. Energy expenditure and
body composition changes after an isocaloric ketogenic diet in overweight
and obese men. Am J Clin Nutr. 2016;104:32433.
27. Wilson JM, Lowery RP, Roberts MD, Sharp MH, Joy JM, Shields KA, Partl
J, Volek JS, DAgostino D. The effects of ketogenic dieting on body
composition, strength, power, and hormonal profiles in resistance
training males. J Strength Cond Res. 2017.
28. Chen JL, Yeh DP, Lee JP, Chen CY, Huang CY, Lee SD, Chen CC, Kuo TB, Kao
CL, Kuo CH. Parasympathetic nervous activity mirrors recovery status in
weightlifting performance after training. J Strength Cond Res. 2011;25:154652.
29. Schoenfeld BJ. The mechanisms of muscle hypertrophy and their
application to resistance training. J Strength Cond Res. 2010;24:285772.
30. Grgic J, Lazinica B, Mikulic P, Krieger JW, Schoenfeld BJ. The effects of short
versus long inter-set rest intervals in resistance training on measures of
muscle hypertrophy: a systematic review. Eur J Sport Sci. 2017;17:98393.
31. Schoenfeld BJ, Pope ZK, Benik FM, Hester GM, Sellers J, Nooner JL, Schnaiter
JA, Bond-Williams KE, Carter AS, Ross CL, et al. Longer Interset rest periods
enhance muscle strength and hypertrophy in resistance-trained men. J
Strength Cond Res. 2016;30:180512.
32. Proske U, Morgan DL. Muscle damage from eccentric exercise: mechanism,
mechanical signs, adaptation and clinical applications. J Physiol. 2001;537:33345.
33. Schoenfeld BJ, Ogborn D, Krieger JW. Effects of resistance training
frequency on measures of muscle hypertrophy: a systematic review and
meta-analysis. Sports Med. 2016;46:168997.
34. Fleck SJ, Kraemer W. Designing resistance training programs. Champaign:
Human Kinetics; 2014.
35. Dalton RL, Sowinski RJ, Grubic TJ, Collins PB, Coletta AM, Reyes AG, Sanchez
B, Koozehchian M, Jung YP, Rasmussen C, et al. Hematological and
hemodynamic responses to acute and short-term Creatine nitrate
supplementation. Nutrients. 2017;9(12).
36. Nakagawa S, Cuthill IC. Effect size, confidence interval and statistical significance: a
practical guide for biologists. Biol Rev Camb Philos Soc. 2007;82:591605.
37. Park HM: Comparing group means: t-tests and one-way ANOVA using Stata,
SAS, R, and SPSS. 2009.
38. Noakes M, Foster PR, Keogh JB, James AP, Mamo JC, Clifton PM.
Comparison of isocaloric very low carbohydrate/high saturated fat and high
carbohydrate/low saturated fat diets on body composition and
cardiovascular risk. Nutr Metab (Lond). 2006;3:7.
39. Brehm BJ, Seeley RJ, Daniels SR, DAlessio DA. A randomized trial comparing
a very low carbohydrate diet and a calorie-restricted low fat diet on body
weight and cardiovascular risk factors in healthy women. J Clin Endocrinol
Metab. 2003;88:161723.
40. Brehm BJ, Spang SE, Lattin BL, Seeley RJ, Daniels SR, DAlessio DA. The role
of energy expenditure in the differential weight loss in obese women on low-
fat and low-carbohydrate diets. J Clin Endocrinol Metab. 2005;90:147582.
41. Brinkworth GD, Noakes M, Clifton PM, Buckley JD. Effects of a low
carbohydrate weight loss diet on exercise capacity and tolerance in obese
subjects. Obesity (Silver Spring). 2009;17:191623.
42. Johnstone AM, Horgan GW, Murison SD, Bremner DM, Lobley GE. Effects of
a high-protein ketogenic diet on hunger, appetite, and weight loss in obese
men feeding ad libitum. Am J Clin Nutr. 2008;87:4455.
43. RuthMR,PortAM,ShahM,BourlandAC,IstfanNW,NelsonKP,Gokce
N, Apovian CM. Consuming a hypocaloric high fat low carbohydrate
diet for 12 weeks lowers C-reactive protein, and raises serum
adiponectin and high density lipoprotein-cholesterol in obese subjects.
Metabolism. 2013;62:177987.
44. Wood RJ, Fernandez ML, Sharman MJ, Silvestre R, Greene CM, Zern TL,
Shrestha S, Judelson DA, Gomez AL, Kraemer WJ, Volek JS. Effects of a
carbohydrate-restricted diet with and without supplemental soluble fiber
on plasma low-density lipoprotein cholesterol and other clinical markers of
cardiovascular risk. Metabolism. 2007;56:5867.
45. Gomez-Arbelaez D, Bellido D, Castro AI, Ordonez-Mayan L, Carreira J, Galban C,
Martinez-Olmos MA, Crujeiras AB, Sajoux I, Casanueva FF. Body composition
changes after very-low-calorie ketogenic diet in obesity evaluated by 3
standardized methods. J Clin Endocrinol Metab. 2017;102:48898.
46. Volek JS, Sharman MJ, Love DM, Avery NG, Gomez AL, Scheett TP, Kraemer
WJ. Body composition and hormonal responses to a carbohydrate-restricted
diet. Metabolism. 2002;51:86470.
47. Upadhyay J, Farr O, Perakakis N, Ghaly W, Mantzoros C. Obesity as a disease.
Med Clin N Am. 2018;102:1333.
48. Ismail I, Keating SE, Baker MK, Johnson NA. A systematic review and meta-
analysis of the effect of aerobic vs. resistance exercise training on visceral
fat. Obes Rev. 2012;13:6891.
49. Willis LH, Slentz CA, Bateman LA, Shields AT, Piner LW, Bales CW, Houmard JA,
Kraus WE. Effects of aerobic and/or resistance training on body mass and fat
mass in overweight or obese adults. J Appl Physiol. 2012;113:18317.
50. Roberts MD, Holland AM, Kephart WC, Mobley CB, Mumford PW, Lowery RP,
Fox CD, McCloskey AE, Shake JJ, Mesquita P, et al. A putative low-
carbohydrate ketogenic diet elicits mild nutritional ketosis but does not
impair the acute or chronic hypertrophic responses to resistance exercise in
rodents. J Appl Physiol (1985). 2016;120:117385.
51. Holland AM, Kephart WC, Mumford PW, Mobley CB, Lowery RP, Shake JJ,
Patel RK, Healy JC, McCullough DJ, Kluess HA, et al. Effects of a ketogenic
diet on adipose tissue, liver, and serum biomarkers in sedentary rats and
rats that exercised via resisted voluntary wheel running. Am J Physiol Regul
Integr Comp Physiol. 2016;311:R33751.
52. Schoenfeld BJ. Science and development of muscle hypertrophy.
Champaign: Human Kinetics; 2016.
53. Schoenfeld BJ. Potential mechanisms for a role of metabolic stress in
hypertrophic adaptations to resistance training. Sports Med. 2013;43:17994.
Vargas et al. Journal of the International Society of Sports Nutrition (2018) 15:31 Page 8 of 9
54. Rauch JT, Silva JE, Lowery RP, McCleary SA, Shields KA, Ormes JA, Sharp MH,
Weiner SI, Georges JI, Volek JS, et al. The effects of ketogenic dieting on
skeletal muscle and fat mass. J Int Soc Sports Nutr. 2014;11:P40.
55. Okamura T, Hashimoto Y, Hamaguchi M, Obora A, Kojima T, Fukui M.
Ectopic fat obesity presents the greatest risk for incident type 2 diabetes: a
population-based longitudinal study. Int J Obes. 2018.
56. Schousboe JT, Langsetmo L, Schwartz AV, Taylor BC, Vo TN, Kats AM,
Barrett-Connor E, Orwoll ES, Marshall LM, Miljkovic I, et al. Comparison of
associations of DXA and CT visceral adipose tissue measures with insulin
resistance, lipid levels, and inflammatory markers. J Clin Densitom. 2017;20:
Vargas et al. Journal of the International Society of Sports Nutrition (2018) 15:31 Page 9 of 9
... This reduction may impair training session performance by limiting energy regeneration, leading to an inability to sustain elevated force production throughout the training session (25). For example, some studies have reported impaired performance and adaptations following a low-CHO diet (17,25,31,43). Moreover, some studies report blunted gains in muscle mass when RT is combined with lower-versus higher-CHO diets (17,18,31,43), suggesting that low-CHO diets are suboptimal for maximizing muscle growth. ...
... For example, some studies have reported impaired performance and adaptations following a low-CHO diet (17,25,31,43). Moreover, some studies report blunted gains in muscle mass when RT is combined with lower-versus higher-CHO diets (17,18,31,43), suggesting that low-CHO diets are suboptimal for maximizing muscle growth. However, it should be noted that the low-CHO-diet groups in these studies were most likely in a caloric deficit, which conceivably impairs anabolic responses to RT (2). ...
... Despite some investigations showing a benefit of low-CHO diets in reducing fat mass (17,31,32,43), our results indicated no effect for either condition in this body composition component. Given the well-established theory that energy balance dictates changes in body mass (39), it is possible to believe that the participants in both groups were not in a caloric deficit. ...
Full-text available
This study's purpose was to compare the effects of different carbohydrate (CHO) intakes on body composition and muscular strength following eight weeks of resistance training (RT) in pre-conditioned men. In addition, we explored the individual responses to different CHO intakes. Twenty-nine young men volunteered to participate in this study. The participants were divided into two groups according to their relative CHO intake: lower (L-CHO; n = 14) and higher (H-CHO; n = 15). Participants performed a RT program four days a week for eight weeks. The lean soft tissue (LST) and fat mass were determined by dual-energy X-ray absorptiometry. Muscular strength was determined by a one-repetition maximum (1RM) test in the bench press, squat, and arm curl exercises. Both groups increased LST (P < 0.05) with no statistical differences between conditions (L-CHO = +0.8% vs. H-CHO = +3.5%). Neither group demonstrated changes in fat mass. Both groups increased 1RM (P < 0.05) in the bench press (L-CHO = +3.6% vs. H-CHO = +5.8%) and squat (L-CHO = +7.5% vs. H-CHO = +9.4%); however, only H-CHO significantly increased arm curl 1RM (P < 0.05) at post-training (L-CHO = +3.0% vs. H-CHO = +6.6%). Responsiveness was greater in H-CHO vs. L-CHO for LST and arm curl 1RM. In conclusion, lower and higher CHO intakes promote similar increase in LST and muscular strength; however, a greater intake may improve the responsiveness to gains in lean mass and arm curl strength in pre-conditioned men.
... Research targeting body composition has focused for decades on obese patients [9], or those of normal weight but not trained [10,11]. The application of this nutritional strategy in resistance-trained participants began recently, with data obtained from our laboratory [12] and the investigations of Greene et al. [13] and Kephart et al. [14]. As a result of this, more studies have emerged that expand the evidence related to KDs and resistance-trained participants. ...
... The loss of FFM in the meta-analysis of Ashtary-Larky [8] may be due to the fact that, of the thirteen studies evaluated, eight were carried out ad libitum [13,14,29,[32][33][34][35][36], and one of them did not report the nutritional data [37]. Therefore, only four studies included specific prescriptions for the consumption of total calories [12,27,28,38]. However, while Vargas et al. [12] initially prescribed ≈39 kcal·kg −1 ·d −1 , there was no nutritional record; therefore, we cannot say that the participants consumed the total energy required. ...
... Therefore, only four studies included specific prescriptions for the consumption of total calories [12,27,28,38]. However, while Vargas et al. [12] initially prescribed ≈39 kcal·kg −1 ·d −1 , there was no nutritional record; therefore, we cannot say that the participants consumed the total energy required. The same difficulty applies to the study by Rhyu et al. [38] where experimental records are unavailable. ...
Full-text available
Reviews focused on the ketogenic diet (KD) based on the increase in fat-free mass (FFM) have been carried out with pathological populations or, failing that, without population differentiation. The aim of this review and meta-analysis was to verify whether a ketogenic diet without programmed energy restriction generates increases in fat-free mass (FFM) in resistance-trained participants. We evaluated the effect of the ketogenic diet, in conjunction with resistance training, on fat-free mass in trained participants. Boolean algorithms from various databases (PubMed, Scopus. and Web of Science) were used, and a total of five studies were located that related to both ketogenic diets and resistance-trained participants. In all, 111 athletes or resistance-trained participants (87 male and 24 female) were evaluated in the studies analyzed. We found no significant differences between groups in the FFM variables, and more research is needed to perform studies with similar ketogenic diets and control diet interventions. Ketogenic diets, taking into account the possible side effects, can be an alternative for increasing muscle mass as long as energy surplus is generated; however, their application for eight weeks or more without interruption does not seem to be the best option due to the satiety and lack of adherence generated.
... The high-performance liquid chromatography method, with photodiode array detection, was used for the assessment of serum antioxidants. In order to obtain more reliable results, a fasting sample was obtained and the exposure of the serum to sunlight or other sources of full spectrum radiation was avoided [26]. Serum antioxidant data were expressed in µmol/L, with the exception of retinol, which was expressed in µg/dL. ...
Full-text available
Aging is associated with an increased reactive oxygen species that can decrease muscle strength. Thus, antioxidant substances could be positively associated with muscle strength in older adults. To investigate the association between serum antioxidants and muscle strength in older adults. A cross-sectional study evaluating 1172 individuals (627 men and 545 women), aged 50 to 85 years from NHANES 2001–2002, was performed. Carotenoids (α-carotene, trans-β-carotene, cis-β-carotene, β-cryptoxanthin, lutein/zeaxanthin combination, trans-lycopene), vitamin E, and retinol were analyzed via the high-performance liquid chromatography method. Muscle strength was evaluated by the isokinetic knee extension test. Linear regression was performed to evaluate the association between tertiles of serum antioxidant levels and strength, adjusted for confounders (energy and protein intake, body mass index, sex, age, C-reactive protein, uric acid, race/ethnicity, marital status, annual household income, educational level, physical activity, smoking, hypertension, arthritis, and diabetes). Alpha-carotene levels (p-trend = 0.027) were positively associated with muscle strength. However, serum vitamin E, trans-β-carotene, cis-β-carotene, β-cryptoxanthin, carotenoids, and retinol levels were not associated with strength. Serum α-carotene, but not other antioxidants, was positively associated with muscle strength in older adults.
... In this diet, the consumption of foods such as fish, eggs, cheese, chicken, beef and vegetable oils are quite normal and the consumption of nuts and various seeds is somewhat limited and moderate amounts of vegetables, water, tea, or sometimes low carb diets were consumed. To ensure the status of ketogenic metabolism, daily urine ketone test strip (ACON brand, San Diego, CA92121, USA) was used to control the level of dietary ketones (18,19). ...
Exercise and dietary interventions have been described to positively affect metabolic syndrome (MetS) via molecular induced changes. The purpose of this study was to investigate the effects of dietary carbohydrate restriction and aerobic exercise on Retinol Binding Protein 4 (RBP4) and Fatty Acid Binding Protein 5 (FABP5) in middle-aged men with metabolic syndrome. The study had a randomized, double-blinded, parallel controlled design. Forty middle-aged men with metabolic syndrome (age: 53.97 ± 2.85 years, body mass index = 31.09 ± 1.04 kg/m ² ) were randomly assigned to four groups, aerobic exercise (AE; n=10), Ketogenic diet (KD; n=10), AE combined with KD (AE+KD; n=10) or control (C; n=10). RBP4, FABP5, body composition [body mass, body mass index and body fat], insulin resistance, insulin sensitivity, and MetS factors were evaluated prior to and after the 12-weeks intervention. AE+KD significantly decreased the body fat percentage (p = 0.006), body mass index (p = 0.001), Zmets (p = 0.017), RBP4 (p = 0.017) and the homeostasis model of insulin resistance (HOMA-IR) (p = 0.001) as compared to control group and marginally significantly decreased the Zmets as compared to exercise group (p = 0.086). KD significantly decreased RBP4 levels as compared to control group (p = 0.041). Only the AE intervention (p = 0.045) significantly decreased FABP5 levels. Combining intervention of carbohydrate restriction with AE compared with carbohydrate restriction and AE alone, improved RBP4, HOMA-IR as well as different body composition and MetS factors in middle-aged men with metabolic syndrome.
... Body weight, body mass index, fat mass, and waist circumference could be significantly reduced [51][52][53][54][55]. Patients with NAFLD undergoing a ketogenic diet achieved superior weight loss, with significant visceral adipose tissue and liver fat fraction reductions when compared to the standard diet [56]. Ketogenic diets might be an alternative dietary approach to decrease fat mass and visceral adipose tissue without decreasing lean body mass [57,58]. Our meta-analysis confirmed that ketogenic diets could decrease the fat mass of cancer patients. ...
Full-text available
A ketogenic diet characterized by high fat and low carbohydrate can drive the body to produce a large number of ketone bodies, altering human metabolism. Unlike normal cells, tumor cells have difficulty in consuming ketone bodies. Therefore, the application of ketogenic diets in cancer therapy is gaining attention. However, the effect of ketogenic diets on body parameters of cancer patients is not well established. This meta-analysis aimed to summarize the effects of ketogenic diets on cancer patients in earlier controlled trials. PubMed, Embase, and Cochrane Library were searched for clinical trials that enrolled cancer patients who received ketogenic diets intervention. Ten controlled trials were included in this meta-analysis. Data were extracted and checked by three authors independently. Pooled effect sizes revealed a significant effect of ketogenic diets on body weight (SMD −1.83, 95% CI −2.30 to −1.35; p < 0.00001) and fat mass (SMD −1.52, 95% CI −1.92 to −1.07; p < 0.00001). No significant effect on blood glucose, insulin, or lipid profile except triglycerides was found in the analysis. It had no effect on liver and kidney function except that GGT were decreased a little. There were no significant changes in IGF-1 and TNF-α related to tumor growth. Mental health improvement of cancer patients was supported by several trials. Taken together, findings in this study confirmed that the ketogenic diet was a safe approach for cancer patients reducing body weight and fat mass. In addition, cancer treatment-related indicators changed insignificantly. Ketogenic diets may be beneficial to the quality of life of cancer patients. However, intervention duration in most studies is shorter than 6 months, and the effect of a long-term ketogenic diet is still required further validation. More trials with a larger sample size are necessary to give a more conclusive result; PROSPERO registration number: CRD42021277559.
... 2.6.1. Dual Energy X-ray Absorptiometry DXA scans were performed following all current technical recommendations and the laboratory procedures reported in previous articles published by our research group [35][36][37]. A Lunar Prodigy™ unit was used (General Electric Healthcare, Madison, WI, USA). ...
Full-text available
The estimation of body fat percentage (%BF) from anthropometry-related data requires population-specific equations to avoid incorrect interpretations in young athletes. Waist girth (WG) has been described as potential predictor of fat mass (FM) in several populations; however, there are no valid WG-based equations to estimate body composition in young Colombian athletes. The aim of this STandardisierte BerichtsROutine für Sekundärdaten Analysen STROSA-based study was twofold: i) to validate the relative fat mass (RFM) and its pediatric version (RFMp) compared to dual-energy x-ray absorptiometry (DXA) and ii) to develop a new equation (F20CA) to estimate the fat mass in Colombian children and adolescent elite athletes. A total of 114 young athletes that belong to the 'Team Medellín' program (58F, 56M; 51 children, 63 adolescents; 14.85 [2.38] years; 55.09 [12.16] kg; 162.38 [11.53] cm) participated in this cross-sectional study. The statistical analysis revealed a poor correlation, agreement and concordance of RFMp and RFM estimations with DXA measurements. After model specification using both Ordinary Least Square method and Bayesian analysis, the regression output revealed that sex, body mass-to-waist ratio, and waist-to-stature ratio were the statistically significant predictor variables that account for variability in FM. The new F20CA equation is expressed as FM (kg) = 5.46 * (Sex) + 0.21 * (BM/W [kg/m]) + 81.7 * (W/Stature [cm/cm]) − 41.8 (R 2 = 0.683; SEE = 2.468 kg), where sex is 0 for males and 1 for females. A moderate-to-high correlation and agreement of the F20CA was confirmed within the internal validation data set (R 2 = 0.689; ICC [95%CI] = 0.805 [0.615, 0.904]; RMSE = 2.613 kg). The Bland-Altman analysis corroborated the high concordance between the reference method (DXA) and the F20CA-estimated FM (bias [95% LoA] = 1.02 [−3.77, 5.81] kg), indicating the two methods could be considered interchangeable. Even though external validation is needed, practitioners are advised to use the F20CA in young Colombian athletes with similar characteristics to those who participated in this study.
... It appears that a non-calorie-restricted KD can be used for optimizing BM and body composition. (8) Literature suggests that KD might be an alternative dietary approach to decrease fat mass and visceral adipose tissue without decreasing lean body mass. (9,10) Individuals using ketogenic diet experience fast weight loss in the initial 4 weeks or less. ...
Full-text available
Objective: To find out the effect of a ketogenic Diet (KD) on the biochemical and anthropometric parameters. Methodology: This experimental study was conducted at the physiology laboratory of Khyber Medical University from January 2022 to June 2022. Using non probability convenience sampling, forty-six subjects were recruited for the study following the inclusion and exclusion criteria. Non-probability convenience sampling method was used. Subjects were given KD for twenty-eight days. Blood samples were collected for biochemical parameters along with anthropometric measurements on Day 1 and Day 29 of the study. Paired sample t test was used for pre- and post-trial comparison and ANOVA was used for comparison at day 0, and 29th day. Results: All the physical and chemical parameters like weight, body mass index, MUAC, biceps, Triceps, sub-scapular, waist circumference, hip circumference, fasting blood sugar, ketone level, glucose ketone index, body fat and water mass muscle mass reduced from 1st day to 29th day statically. Two parameters (height and visceral mass) show an insignificant change in results from day 1st to day 29th.
... 2.5.1. Body Composition DXA measurements will be performed following all current recommendations and the laboratory procedures reported in previous articles published by our research group [46][47][48]. To perform the scans, a Lunar Prodigy™ unit will be used (General Electric Healthcare, Madison, WI, USA). ...
Full-text available
Waist girth (WG) represents a quick, simple, and inexpensive tool that correlates with excess of fat mass in humans; however, this measurement does not provide information on body composition. The evaluation of body composition is one of the main components in the assessment of nutritional status. Indeed, the use of anthropometry-based equations to estimate body fat and fat-free mass is a frequent strategy. Considering the lack of validation in the Colombian population, the aim of this research study (the F20 Project) is to externally validate WG-based equations (e.g., relative fat mass), and also to develop and validate new models that include WG to estimate body composition in Colombian adults compared to DXA. This cross-sectional study will be carried out following the guidelines for Strengthening the Reporting of Observational Studies in Epidemiology–Nutritional Epidemiology (STROBE–nut). Using stratified probabilistic sampling, the study population will be adults with different levels of physical activity residing in Medellín and its metropolitan area. The results of this study will not only validate the estimation performance of the current WG-based equations, but they will also develop new equations to estimate body composition in the Colombian population. This will improve professional practice in health, exercise, and sports sciences ( ID #NCT05450588).
Full-text available
As humans age, we lose skeletal muscle mass, even in the absence of disease (sarcopenia), increasing the risk of death. Low mitochondrial mass and activity contributes to sarcopenia. It is our hypothesis that, a ketogenic diet improves skeletal muscle mitochondrial mass and function when they have declined due to aging or disease, but not in athletes where mitochondrial quality is high.
Exercise and diet are two essential interventions in weight control. The purpose of this study was to compare the effectiveness of two exercise training types during a ketogenic diet (KD) on appetite sensation, appetite-regulating hormones, and body composition in overweight or obese man. Thirty-six men, overweight or with obesity, voluntarily participated in this study. The participants were randomly assigned into three groups, including KD ( n = 12), aerobic training during KD (AT-KD) ( n = 12), and resistance training during KD (RT-KD) ( n = 12) groups. The participants followed a low-carbohydrate diet for 6 weeks. Exercise training programs consisted of three sessions per week over 6 weeks. Appetite sensation was analyzed using a visual analogue scale (VAS) in fasting and postprandial states. The Enzyme-Linked Immunosorbent Assay (ELISA) method analyzed appetite-regulating hormones, including spexin, leptin, and acylated ghrelin, in a fasting state. Body composition was measured using bioelectrical impedance analysis (BIA). Furthermore, the ketosis state was monitored by measuring urinary ketones weekly. The results indicated that in both AT-KD and RT-KD groups, spexin and acylated ghrelin increased while leptin decreased without any between-group differences. Hunger and prospective food consumption (PFC) declined while satiety and fullness increased in all groups. The AT-KD group experienced a significant decrease in hunger and PFC, while fullness increased compared with the KD group. Fat mass, weight, and body mass index (BMI) decreased in all groups. Lean body mass increased in the RT-KD group (+2.66 kg) compared with both AT-KD and KD groups (−1.71 and −1.33 kg, respectively). This study demonstrated that AT-KD and RT-KD effectively altered appetite-regulating hormones and suppressed appetite sensation. In addition, both interventions had a favorable effect on weight loss and body fat reduction, with a more pronounced effect of RT-KD on maintaining lean body mass in overweight or obese men.
Full-text available
Objectives: Obesity is a risk factor for type 2 diabetes mellitus. Among obesity, visceral fat obesity, and ectopic fat obesity, it has been unclear which has the greatest effect on incident diabetes. Methods: In this historical cohort study of 8430 men and 7034 women, we investigated the effect of obesity phenotypes on incident diabetes. Obesity, visceral fat obesity, and ectopic fat obesity were defined as body mass index ≥25 kg/m2, waist circumference ≥90 cm in men or ≥80 cm in women, and having fatty liver diagnosed by abdominal ultrasonography, respectively. We divided the participants into eight groups according to the presence or absence of the three obesity phenotypes. Results: During the median 5.8 years follow-up for men and 5.1 years follow-up for women, 286 men and 87 women developed diabetes. Compared to the non-obese group, the hazard ratios (HRs) of incident diabetes in the only-obesity, only-visceral fat obesity, only-ectopic fat obesity groups, and with all-three types of obesity group were 1.85 (95%CI 1.06-3.26, p = 0.05) in men and 1.79 (0.24-13.21, p = 0.60) in women, 3.41 (2.51-4.64, p < 0.001) in men and 2.30 (0.87-6.05, p = 0.12) in women, 4.74 (1.91-11.70, p < 0.001) in men and 13.99 (7.23-27.09, p < 0.001) in women and 10.5 (8.02-13.8, p < 0.001) in men and 30.0 (18.0-50.0, p < 0.001) in women. Moreover, the risk of incident diabetes of the groups with ectopic fat obesity were almost higher than that of the four groups without ectopic fat obesity. Conclusion: Ectopic fat obesity presented the greatest risk of incident type 2 diabetes.
Full-text available
In a double-blind, crossover, randomized and placebo-controlled trial; 28 men and women ingested a placebo (PLA), 3 g of creatine nitrate (CNL), and 6 g of creatine nitrate (CNH) for 6 days. Participants repeated the experiment with the alternate supplements after a 7-day washout. Hemodynamic responses to a postural challenge, fasting blood samples, and bench press, leg press, and cycling time trial performance and recovery were assessed. Data were analyzed by univariate, multivariate, and repeated measures general linear models (GLM). No significant differences were found among treatments for hemodynamic responses, clinical blood markers or self-reported side effects. After 5 days of supplementation, one repetition maximum (1RM) bench press improved significantly for CNH (mean change, 95% CI; 6.1 [3.5, 8.7] kg) but not PLA (0.7 [−1.6, 3.0] kg or CNL (2.0 [−0.9, 4.9] kg, CNH, p = 0.01). CNH participants also tended to experience an attenuated loss in 1RM strength during the recovery performance tests following supplementation on day 5 (PLA: −9.3 [−13.5, −5.0], CNL: −9.3 [−13.5, −5.1], CNH: −3.9 [−6.6, −1.2] kg, p = 0.07). After 5 days, pre-supplementation 1RM leg press values increased significantly, only with CNH (24.7 [8.8, 40.6] kg, but not PLA (13.9 [−15.7, 43.5] or CNL (14.6 [−0.5, 29.7]). Further, post-supplementation 1RM leg press recovery did not decrease significantly for CNH (−13.3 [−31.9, 5.3], but did for PLA (−30.5 [−53.4, −7.7] and CNL (−29.0 [−49.5, −8.4]). CNL treatment promoted an increase in bench press repetitions at 70% of 1RM during recovery on day 5 (PLA: 0.4 [−0.8, 1.6], CNL: 0.9 [0.35, 1.5], CNH: 0.5 [−0.2, 0.3], p = 0.56), greater leg press endurance prior to supplementation on day 5 (PLA: −0.2 [−1.6, 1.2], CNL: 0.9 [0.2, 1.6], CNH: 0.2 [−0.5, 0.9], p = 0.25) and greater leg press endurance during recovery on day 5 (PLA: −0.03 [−1.2, 1.1], CNL: 1.1 [0.3, 1.9], CNH: 0.4 [−0.4, 1.2], p = 0.23). Cycling time trial performance (4 km) was not affected. Results indicate that creatine nitrate supplementation, up to a 6 g dose, for 6 days, appears to be safe and provide some ergogenic benefit.
Full-text available
The ketogenic diet (KD) is increasingly being used to treat patients with intractable epilepsy. Despite decades of research, the reason for its success, when anticonvulsants have failed, is still not completely understood. There are, however, many candidate mechanisms which can be grouped into those that alter neuronal excitability at the synapse, and those that confer neuroprotection. The molecular underpinning of these mechanisms centres on the shift from glucose- to lipid-based energy generation that accompanies a high fat/low carbohydrate diet. Here we describe how changes in the relative abundances of energy substrates (ketone bodies), intermediates of glycolysis and fat metabolism, and metabolic end products (ATP, reactive oxygen species) underlie many of the antiepileptic effects of the KD. We propose that the success of the KD for treating epilepsy lies in the large variety of antiepileptic mechanisms that it confers. Different subsets of the mechanisms may be clinicallyrelevant in different patients. We extend this to suggest that the broad benefits of the KD could therefore be achieved by pharmacologically promoting the production of ketone bodies in the liver as they represent a key mediator that is common to all of the proposed mechanisms.
Full-text available
Dietary interventions are the cornerstone of obesity treatment. The optimal dietary approach to weight loss is a hotly debated topic among health professionals and the lay public alike. An emerging body of evidence suggests that a higher level of adherence to a diet, regardless of the type of diet, is an important factor in weight loss success over the short and long term. Key strategies to improve adherence include designing dietary weight loss interventions (such as ketogenic diets) that help to control the increased drive to eat that accompanies weight loss, tailoring dietary interventions to a person's dietary preferences (and nutritional requirements), and promoting self-monitoring of food intake. The aim of this paper is to examine these strategies, which can be used to improve adherence and thereby increase the success of dietary weight loss interventions.
Full-text available
Although the effects of short versus long inter-set rest intervals in resistance training on measures of muscle hypertrophy have been investigated in several studies, the findings are equivocal and the practical implications remain unclear. In an attempt to provide clarity on the topic, we performed a systematic literature search of PubMed/MEDLINE, Scopus, Web of Science, Cochrane Library, and Physiotherapy Evidence Database (PEDro) electronic databases. Six studies were found to have met the inclusion criteria: (a) an experimental trial published in an English-language peer-reviewed journal; (b) the study compared the use of short (≤60 s) to long (>60 s) inter-set rest intervals in a traditional dynamic resistance exercise using both concentric and eccentric muscle actions, with the only difference in resistance training among groups being the inter-set rest interval duration; (c) at least one method of measuring changes in muscle mass was used in the study; (d) the study lasted for a minimum of four weeks, employed a training frequency of ≥2 resistance training days per week, and (e) used human participants without known chronic disease or injury. Current evidence indicates that both short and long inter-set rest intervals may be useful when training for achieving gains in muscle hypertrophy. Novel findings involving trained participants using measures sensitive to detect changes in muscle hypertrophy suggest a possible advantage for the use of long rest intervals to elicit hypertrophic effects. However, due to the paucity of studies with similar designs, further research is needed to provide a clear differentiation between these two approaches.
Full-text available
Background: Ketogenic diets (KDs) have gained popularity among patients and researchers alike due to their putative anti-tumor mechanisms. However, the question remains which conclusions can be drawn from the available human data thus far concerning the safety and efficacy of KDs for cancer patients. Methods: A realist review utilizing a matrix-analytical approach was conducted according the RAMESES publication standards. All available human studies were systematically analyzed and supplemented with results from animal studies. Evidence and confirmation were treated as separate concepts. Results: 29 animal and 24 human studies were included in the analysis. The majority of animal studies (72%) yielded evidence for an anti-tumor effect of KDs. Evidential support for such effects in humans was weak and limited to individual cases, but a probabilistic argument shows that the available data strengthen the belief in the anti-tumor effect hypothesis at least for some individuals. Evidence for pro-tumor effects was lacking completely. Conclusions: Feasibility of KDs for cancer patients has been shown in various contexts. The probability of achieving an anti-tumor effect seems greater than that of causing serious side effects when offering KDs to cancer patients. Future controlled trials would provide stronger evidence for or against the anti-tumor effect hypothesis
Obesity is a complex disease with many causal factors, associated with multiple comorbidities that contribute to significant morbidity and mortality. It is a highly prevalent disease that poses an enormous health and economic burden to society. This article reviews the mechanisms of obesity and its related comorbidities.
Purpose: The ketogenic diet (KD) has been proven to be effective in children with refractory epilepsy and is recommended by the National Institute of Health and Care Excellence (NICE). There is no randomised control trial (RCT) evidence for the clinical or cost effectiveness of KD in adults, for whom the KD is not currently recommended. We assessed the feasibility of the modified ketogenic diet (MKD) in adults with refractory epilepsy along with the willingness of patients to participate in a future RCT. Methods: The service evaluation was undertaken in two parts; questionnaire and diet evaluation. Results: 102 patients completed a questionnaire, of which 51 patients were willing to try the MKD for 3 months to assess effect on seizures. Forty three patients were willing to participate in a clinical trial to investigate deliverability, efficacy and tolerability. Thirty seven of which would still be willing to participate if the trial were randomised. Of the 17 patients who commenced the diet, 9 completed the 12 week period, 7 of which stayed on the diet for the longer term. Constipation (n=6) and loose stools (n=3) were the only reported adverse effects. Conclusion: Our results indicate that there is demand for a ketogenic diet service in adults. The MKD is well tolerated, feasible and financially viable to deliver to adults with epilepsy in the NHS. There is also interest in and willingness to participate in a UK based RCT that would ultimately inform decisions about commissioning appropriate services.
Americans have embraced a large number of diets in an attempt to manage obesity, improve quality of life, and address specific health problems. Among diets developed to address health problems, the ketogenic diet has had a long and variable history. Developed in the 1920s by a faith healer to help children with epilepsy, this diet induces a state that mimics carbohydrate starvation. As medications became available and effectively addressed seizures, the diet fell out of favor. During the last few decades, researchers and clinicians have learned that it can be useful in children and adults with refractory epilepsy and a variety of other conditions. Once again, pharmacists may encounter patients who are employing dietary management of serious health problems. This very high-fat diet almost eliminates carbohydrates from the patient's food selection. The result is the substitution of ketone bodies as a source of energy. Today's ketogenic diet has been modified with scientifically proven adjustments to increase palatability and help with adherence. Effective for some forms of epilepsy, the ketogenic diet also seems to have some utility in Alzheimer's disease, Parkinson's disease, and glaucoma, and many Americans are using it to lose weight. Consultant pharmacists may field questions about this diet, its potential to correct or alleviate health conditions, and its limitations. The article discusses the ketogenic diet's strengths, limitations, potential mechanisms, and use in a number of conditions with an emphasis on the elderly.