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Effects of lupin-enriched foods on body composition and cardiovascular disease risk factors: A 12-month randomized controlled weight loss trial

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Effects of lupin-enriched foods on body composition and cardiovascular disease risk factors: A 12-month randomized controlled weight loss trial

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Regular consumption of diets with increased protein or fibre intakes may benefit body weight and composition and cardiovascular disease risk factors. Lupin flour is a novel food ingredient high in protein and fibre. To investigate the effects of a lupin-enriched diet, during and following energy restriction, on body weight and composition and cardiovascular disease risk factors in overweight individuals. Participants (n = 131) were recruited to a 12-month parallel-design trial. They were randomly assigned to consume lupin-enriched foods or matching high-carbohydrate control foods. All participants underwent 3 months of weight loss, 1 month of weight stabilization and 8 months of weight maintenance. Body weight and composition and cardiovascular disease risk factors were assessed at baseline, 4 and 12 months. Lupin, relative to control, did not significantly influence (mean difference (95% CI)) weight loss at 4 months (0.1 kg (-1.2, 1.4)) and 12 months (-0.6 kg (-2.0, 0.8)), maintenance of weight loss from 4 to 12 months (-0.7 kg (-1.83, 0.48)) or measures of body fat and fat-free mass. Relative to control, 24-h ambulatory systolic (-1.3 mm Hg (-2.4, -0.3), P = 0.016) and diastolic (-1.0 mm Hg (-1.9, -0.2), P = 0.021) blood pressures were lower at 12 months but not at 4 months; fasting insulin concentrations and homeostasis model assessment (HOMA) scores were significantly lower at 4 months (-1.2 mU l(-1) (-1.3, -1.1), P = 0.004 and -0.6 units (-1.0, -0.19), P = 0.004) and 12 months (-1.3 mU l(-1) (-1.4, -1.1), P < 0.001 and -0.7 units (-1.1, -0.24), P = 0.002). A diet higher in protein and fibre derived from lupin-enriched foods does not enhance weight loss or improve the maintenance of weight loss. However, such a diet may provide cardiovascular health benefits in terms of insulin sensitivity and blood pressure.
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ORIGINAL ARTICLE
Effects of lupin-enriched foods on body composition
and cardiovascular disease risk factors: a 12-month
randomized controlled weight loss trial
R Belski
1,2
, TA Mori
1,2
, IB Puddey
1,2
, S Sipsas
3
, RJ Woodman
4
, TR Ackland
5
, LJ Beilin
1,2
, ER Dove
1,2
,
NB Carlyon
1,2
, V Jayaseena
2,6
and JM Hodgson
1,2
1
School of Medicine and Pharmacology, University of Western Australia, Perth, Western Australia, Australia;
2
The WAIMR
Centre for Food and Genomic Medicine, Perth, Western Australia, Australia;
3
Department of Agriculture and Food, Western
Australia, Australia;
4
School of Medicine, Flinders University, Adelaide, South Australia, Australia;
5
School of Sport Science
Exercise and Health, University of Western Australia, Perth, Western Australia, Australia and
6
School of Public Health,
Curtin Health Innovation Research Centre, Curtin University, Perth, Western Australia, Australia
Background: Regular consumption of diets with increased protein or fibre intakes may benefit body weight and composition
and cardiovascular disease risk factors. Lupin flour is a novel food ingredient high in protein and fibre.
Objective: To investigate the effects of a lupin-enriched diet, during and following energy restriction, on body weight and
composition and cardiovascular disease risk factors in overweight individuals.
Design: Participants (n¼131) were recruited to a 12-month parallel-design trial. They were randomly assigned to consume
lupin-enriched foods or matching high-carbohydrate control foods. All participants underwent 3 months of weight loss,
1 month of weight stabilization and 8 months of weight maintenance. Body weight and composition and cardiovascular disease
risk factors were assessed at baseline, 4 and 12 months.
Results: Lupin, relative to control, did not significantly influence (mean difference (95% CI)) weight loss at 4 months (0.1kg
(1.2, 1.4)) and 12 months (0.6 kg (2.0, 0.8)), maintenance of weight loss from 4 to 12 months (0.7 kg (1.83, 0.48)) or
measures of body fat and fat-free mass. Relative to control, 24-h ambulatory systolic (1.3 mm Hg (2.4, 0.3), P¼0.016) and
diastolic (1.0 mm Hg (1.9, 0.2), P¼0.021) blood pressures were lower at 12 months but not at 4 months; fasting
insulin concentrations and homeostasis model assessment (HOMA) scores were significantly lower at 4 months (1.2 mU l
–1
(1.3, 1.1), P¼0.004 and 0.6 units (1.0, 0.19), P¼0.004) and 12 months (1.3 mU l
–1
(1.4, 1.1), Po0.001 and
0.7 units (1.1, 0.24), P¼0.002).
Conclusions: A diet higher in protein and fibre derived from lupin-enriched foods does not enhance weight loss or improve the
maintenance of weight loss. However, such a diet may provide cardiovascular health benefits in terms of insulin sensitivity and
blood pressure.
International Journal of Obesity (2011) 35, 810–819; doi:10.1038/ijo.2010.213; published online 12 October 2010
Keywords: lupin; weight loss; blood pressure; insulin; lipids
Introduction
Data suggest that a higher protein or fibre diet can enhance
satiety and reduce energy intake acutely, and contribute to
body weight loss in the longer term.
1–4
Increasing both
protein and fibre in the diet can be difficult because popular
low-carbohydrate, high-protein diets tend to have quite low
fibre intakes.
5
Thus, there are limited data on the effects of
regular consumption of diets higher in both protein and
fibre at the expense of starch. Protein and fibre can
independently increase satiety,
1–5
and these effects are likely
to result via different mechanisms. Fibre appears to have
a role in satiety and satiation through energy dilution,
increased mastication, gastric distension, delayed gastric
emptying and changes in orexigenic hormones.
3
The
mechanisms for the effects of protein are less clear but
protein may influence satiety via orexigenic hormones.
6
Therefore, it could be anticipated that their combined
effects on body weight and composition would be additive.
Received 15 June 2010; revised 12 August 2010; accepted 23 August 2010;
published online 12 October 2010
Correspondence: R Belski, School of Medicine and Pharmacology, Royal Perth
Hospital Unit, GPO Box X2213, Perth, Western Australia 6847, Australia.
E-mail: regina.belski@uwa.edu.au
International Journal of Obesity (2011) 35,810– 819
&
2011 Macmillan Publishers Limited All rights reserved 0307-0565/11
www.nature.com/ijo
A practical approach to increasing both protein and fibre
content of processed foods is to incorporate high protein
and fibre ingredients into commonly consumed high-
carbohydrate foods. There is evidence that this approach
could also improve cardiovascular disease risk factors such
as blood pressure
7
and blood lipids.
8,9
Lupin flour is a novel food ingredient derived from the
endosperm of lupin. It contains 40–45% protein, 25–30%
fibre and negligible sugar and starch.
10
It is commonly used
as a minor food ingredient in baked foods, but can be used to
partially replace wheat flour in foods such as bread and
pasta, resulting in significant increases in protein and fibre
levels.
11,12
These foods remain palatable and are acceptable
to consumers.
12
We have previously shown that high protein and fibre
lupin flour-enriched bread, with 40% wheat flour replace-
ment, significantly reduced appetite and energy intake
acutely.
8
We also showed that the lupin-enriched meal
acutely suppressed plasma ghrelin,
8
an orexigenic hormone
thought to stimulate appetite.
13
If consumption of lupin
flour-enriched foods has similar effects on energy intake in
the longer term, such effects could translate into weight loss.
Diets higher in plant protein and fibre may also benefit
blood pressure,
14–17
serum lipids
18,19
and glucose and insulin
metabolism.
20,21
In a previous 16-week trial, we showed that
consumption of lupin flour-enriched bread reduced 24-h
systolic blood pressure by 3.0 mm Hg.
22
Lupin-enriched diets
have also been shown to reduce blood cholesterol concen-
trations in animals
23–25
and humans.
26
Furthermore, acute
reductions in postprandial glucose and insulin have been
demonstrated with lupin flour-enriched bread consump-
tion,
12,27
but longer-term effects are not clear.
11
The effects
of a lupin-enriched diet on body weight, body composition
and cardiovascular disease risk factors in the setting of
weight loss and longer-term maintenance of weight loss
have not been investigated.
Therefore, the objective of this study was to investigate the
effects of a lupin-enriched diet, during and following energy
restriction, on body weight, body composition and cardio-
vascular disease risk factors in overweight men and women.
Subjects and methods
Participants
Overweight and obese (body mass index 27–35kg m
–2
),
otherwise healthy volunteers aged 20–71 years were
recruited from the Western Australian (WA) population
through newspaper advertisements from August 2007
to May 2008, into a single-site study. Exclusion criteria
included history of cardiovascular or peripheral vascular
disease, diabetes, history of asthma, renal disease, liver
disease or gout, a psychiatric illness, history of major gastro-
intestinal problems, other major illnesses such as cancer,
hypertension (systolic blood pressure 4150 mm Hg or
diastolic blood pressure 495 mm Hg), use of antihyperten-
sive agents, total cholesterol 46.2 mmol l
–1
or triglycerides
42.0 mmol l
–1
, use of lipid-lowering medications, women
who were pregnant or intended to become pregnant, history
of food allergies, current/recent weight loss/gain (change of
46% body weight over last 6 months) and alcohol intake
4140 g alcohol per week for women and 4280 g alcohol per
week for men. In addition, individuals with no history of
diabetes, but with fasting plasma glucose concentrations
X6.0 mmol l
–1
were excluded. Of the B800 telephone
respondents screened by questionnaire, 231 were eligible
and willing to attend the Research Unit for a screening visit.
Of those 231 participants, 134 met the inclusion criteria and
131 were randomized and commenced the study (68 men
and 63 women). All procedures followed were in accordance
with institutional guidelines. The study was approved by the
University of Western Australia Human Research Ethics
Committee, and all participants provided written informed
consent. The study was registered with the Australian
New Zealand Clinical Trials Registry ACTRN12607000434493.
Study design
A randomized, controlled, double-blind parallel design trial
was performed. Eligible participants were randomized into
either a control group (consuming control foods) or a lupin
group (consuming foods enriched with lupin flour). Eligible
individuals were matched for body mass index, age
and gender and randomly assigned (1:1) using computer-
generated random numbers to either the control or lupin
group. The randomization was performed by an independent
person and group allocation was sealed in opaque envelopes.
Participants and researchers responsible for dietetic inter-
vention and assessment of outcomes measures were blinded
as to group assignment. The researcher responsible for food
distribution was not blinded to group assignment.
After randomization, participants commenced on a
3-month weight loss program (B35% energy restriction)
designed by a dietitian to achieve an average weight loss
in all participants of between 7 and 8% of body weight.
This incorporated the consumption of the assigned foods,
monthly dietetic visits and fortnightly dietary phone
consultations. This was followed by a 1-month weight
stabilization period where participants ceased weight loss
and maintained body weight within 1.5 kg. During the
following 8-month weight maintenance stage, participants
followed an ad libitum diet incorporating the assigned foods.
The aim during this period was to maintain the weight loss
achieved. The primary outcome variable was weight, with
the secondary outcomes being body composition, analysed
by dual-energy X-ray absorptiometry, including body fat
mass and fat-free mass, and cardiovascular disease risk factors
including blood pressure, fasting blood lipids, glucose and
insulin. All assessments of outcome variables were under-
taken at baseline, 4 months and 12 months. The study was
run with two cohorts: the first cohort completed the study
Effects of lupin on body weight and CVD risk
R Belski et al
811
International Journal of Obesity
from October 2007 to November 2008, and the second
cohort completed the study from April 2008 to May 2009.
Foods
Lupin or control foods were provided to participants and
were consumed in place of other cereal-based food products
normally used in the diet. The three foods provided were
bread, biscuits and pasta. The bread and biscuits were baked
at Bodhi’s Bakery (Fremantle, Western Australia, Australia).
The bread was sliced and supplied fresh or frozen to the
participants every month, commencing from baseline.
Participants were required to freeze the bread. The biscuits
were provided fresh every month starting at the 4-month
appointment. The pasta was produced at Belmar Foods
(Balcatta, Western Australia, Australia) and was provided
fresh every month starting at the 6-month appointment. The
food introduction was staggered to keep the initial weight
loss period of the study simple, and to aid retention in the
later phases of the study by increasing variety.
The lupin flour in the lupin products was substituted for
wheat flour, primarily wholemeal, in the control products.
The incorporation rate of lupin flour into lupin products
was 25–40% by weight. The two sets of food products were
matched as closely as possible in colour, taste and texture,
and sensory acceptability and energy, fat and sodium
content in order to assist in blinding of participants to their
treatment group allocation (Table 1).
Dietary assessment
Dietary intake was assessed using a 3-day food diary designed
by a qualified dietitian, based on a previously validated 3-day
estimated food record.
28
Participants were given both verbal
and written instructions on its completion using house-
hold measures to quantify intake. The food diaries were
completed on two weekdays and one day of the weekend.
A weekly log of alcohol intake was included in the food
diary, where participants were asked to record their alcohol
consumption over 7 days. Food intake data were analysed
using FoodWorks Professional 2007 Software (Xyris, Brisbane,
Australia) based on the Australian Food Composition
Database to determine average daily energy, protein, total
fat, cholesterol, carbohydrate, dietary fibre, mineral and
alcohol intake.
Physical activity assessment
Participants were instructed to maintain their current
physical activity levels for the first 4 months of the study
(during the weight loss period and stabilization). During
the 8-month weight maintenance stage, participants were
free to alter their usual physical activity if they wished.
Physical activity was assessed using the Stanford 7-day
Recall Interview
29
and the International Physical Activity
Questionnaire, which has previously been shown to have
an acceptable test-retest reliability and criterion validity.
30
Body weight and composition
Body weight was determined using Wedderburn digital scales
(20–200 kg) (Wedderburn, Perth, Western Australia, Austra-
lia). Participants were weighed with minimal clothing,
without shoes, and weight was recorded to the nearest
0.1 kg. Body composition was measured with dual-energy
X-ray absorptiometry (GE Lunar Prodigy, GE Lunar
Corporation, Madison, WI, USA) by a trained researcher.
11
The exclusion criteria for the dual-energy X-ray absorptio-
metry scan included a chance of pregnancy, a recent barium
test or nuclear medicine scan. At the start of each session,
quality assurance and quality control tests were performed.
Participants removed jewellery/metal objects, and wore
minimal clothing or a hospital gown. Participants were
supine on an X-ray bed, centred within the scan line with
their head 3 cm from the top border. The dual-energy X-ray
absorptiometry scanner reliability is high with coefficients of
variation of 0.6% for fat tissue and 4.5% for lean tissue.
31
Blood pressure
The 24-h ambulatory blood pressure measurements
were performed using Spacelab monitors (Model 90217;
SpaceLabs Medical Inc., Issaquah, WA, USA). The monitor
was programmed to take an oscillometric reading every
20 min during waking hours and every 30 min during
sleeping hours. The monitor cuff was fitted to the non-
dominant arm approximately 2.5 cm above the antecubital
fossa. The Spacelab machine was calibrated by taking a
reading with Spacelab monitor connected to a mercury
sphygmomanometer and at least three readings recorded by
the monitor were within ±7 mm Hg of the readings observed
on the sphygmomanometer after correcting for bleep stop
value. A valid 24 h recording was defined as a minimum
of 80% successful readings, with hourly mean blood pressure
recordings missing for o4 h of the 24 h period. The 24-h
ambulatory blood pressure provides greater statistical power
than casual (clinical) measurement. Small effects on blood
pressure may be missed using single clinical measurements.
This is partly a result of increased power with multiple
measurements over 24 h, but may also be the result of
Table 1 The composition of the lupin flour-enriched foods and control foods
per 100 g
Nutrient (per 100 g) Food provided
Lupin flour enriched Control
Bread Biscuits Pasta Bread Biscuits Pasta
Energy (MJ) 0.9 1.5 1.3 1.0 1.8 1.4
Carbohydrates (g) 27.1 35.0 48.0 42.0 64.8 66.2
Fat (g) 2.8 16.4 2.8 2.9 16.1 1.2
Protein (g) 16.0 19.0 20.1 7.6 4.2 10.7
Fibre (g) 11.1 11.2 11.0 5.4 3.6 3.2
Effects of lupin on body weight and CVD risk
R Belski et al
812
International Journal of Obesity
measuring a different parameter not influenced by the ‘white
coat’ effect.
32
Biochemistry
Venous blood samples were collected following a 12-h fast
from the antecubital vein of the forearm. Blood was collected
into BD Vacutainer (Franklin Lakes, NJ, USA) serum separator
tubes and EDTA tubes. All biochemical and haematology
analyses were performed in the PathWest Laboratory at Royal
Perth Hospital (WA, Australia). Analyses of lipids, insulin and
high-sensitivity C-reactive protein were performed on sera
stored at 80 1C in a single batch to reduce variability.
Full blood picture was performed on venous blood
collected into an EDTA tube on an Abbott Cell-Dyn 4000
(CD4K) instrument (Abbott Laboratories, Abbott Park, IL,
USA). Serum total cholesterol, high-density lipoprotein
(HDL) cholesterol and triglyceride concentrations were
analysed with a fully automated analyser (Architect
c16000; Abbott Laboratories). The assay coefficients of
variation were 0.9% for total cholesterol, 1.7% for triglyce-
rides and 2.6% for HDL cholesterol. Serum low-density
lipoprotein cholesterol was calculated using the Friedewald
equation.
33
Serum glucose was measured using a hexokinase/
G-6-PDH method (Abbott Laboratories) using a fully auto-
mated analyser (Architect c16000). The assay coefficient of
variation was 2.7%. Serum insulin was analysed by immuno-
assay (Abbott Laboratories) using a fully automated analyser
(Architect c16000), with an assay coefficient of variation
of 1.5%. The homeostasis model assessment (HOMA) score
was calculated with the following formula,
34
(serum glucose
(mmol l
–1
)serum insulin (mUml
–1
)/22.5), to estimate
changes in insulin sensitivity. High-sensitivity C-reactive
protein was analysed using BN Systems (Dade Behring,
Germany) with a BNII analyser, assay coefficient of variation
of 4.4%.
Statistics
Statistical analyses were performed using SPSS 15.0 software
(SPSS Chicago, IL, USA) or Stata 11.0 software (StataCorp,
College Station, TX, USA). The sample for this study was
calculated on the primary outcome of body weight. With
a¼0.05, 50 participants per group provided 480% power to
detect a 2-kg difference between groups. This would also
provide 480% power to detect a 10% difference in fasting
glucose and a 10% difference in low-density lipoprotein
cholesterol. Secondary outcome measures included body fat
mass, fat-free mass and fasting serum concentrations of
cholesterol, triglycerides, glucose and insulin. To allow for
dropouts, we planned to recruit at least 130 participants to
this study. The primary analysis included participants who
completed the intervention. Intention-to-treat analysis was
also performed. For descriptive data, results are presented as
mean±s.d., except for insulin and triglycerides that were
log-transformed and are reported as geometric mean and
95% confidence interval (CI). The baseline-adjusted 4- and
12-month values and between-group differences are
presented as mean (95% CI) with Po0.05 being the level of
significance in two-tailed testing. At baseline, characteristics
of participants in the two groups were compared using the
independent-samples t-test and the w
2
test for categorical
variables. The Stata ‘xtmixed’ and ‘margins’ commands were
used to assess baseline-adjusted between-group differences
at 4 and 12 months. Fixed effects in each model (except for
24-h blood pressure) were baseline value of the variable,
an indicator variable for month 4, month 12, and for
treatment group, a treatment group month 4 interaction
term and a treatment group month 12 interaction term.
A subject-specific random intercept term was also included.
For 24-h blood pressure, fixed effects were treatment group,
month (as a categorical variableFthat is, with values 0, 4 or 12),
month treatment group and hour (as a categorical vari-
able). A subject-specific random intercept and a subject-
specific random slope for hour (treated as a factor using the
R.hour notation in Stata) were included as random effects.
Results
Participants
A total of 131 participants (63 control, 68 lupin) aged 22–71
years were randomized and commenced the study. In all, 110
(55 control, 55 lupin) participants completed the trial to
4 months and 93 participants (47 control, 46 lupin; 71%)
completed the trial to 12 months (Figure 1). The reasons for
withdrawal from the lupin group included: not able to
commit to time requirements of study (n¼10), relocation to
other city (n¼5), commencement or change in medication
or health status (n¼4), inability to consume foods provided
in required amount (n¼2), and one participant failed to
disclose a pre-existing condition prior to randomization and
was withdrawn immediately. The reasons for withdrawal
from the control group included: not able to commit to time
requirements of study (n¼11), relocation to other city
(n¼1), commencement or change in medication or health
status (n¼3) and inability to consume foods provided in the
required amount (n¼1).
The two groups (control and lupin) were well matched at
baseline (Table 2). There were no significant differences in
baseline characteristics between the participants who completed
the trial to 4 months or 12 months and those who withdrew.
There were no reported adverse effects from eating either the
control or the lupin foods during the 12-month study.
Energy and nutrient intake and physical activity
Energy and nutrient intakes and levels of physical activity
were well matched between groups at baseline (Table 3).
During the 3-month weight loss period, both groups were
placed on B35% energy-restricted diet. During the 8-month
ad libitum weight maintenance period, the energy intakes of
Effects of lupin on body weight and CVD risk
R Belski et al
813
International Journal of Obesity
both groups increased but remained below baseline energy
intake. Estimated energy intakes during the weight loss and
weight maintenance periods were not significantly different
between groups (Table 3). At both 4 and 12 months, there
were higher protein and fibre intakes and lower carbohydrate
intakes in the lupin group relative to control. At 4 and 12
months, respectively, mean protein intake was higher by 19 g
per day (95% CI: 8, 29; Po0.001) and 15 g per day (95% CI:
3, 28; Po0.001); fibre intake was higher by 9 g per day (95%
CI: 6, 12; Po0.001) and 14 g per day (95% CI: 10, 18;
Po0.001); and carbohydrate intake was lower by 26 g
per day (95% CI: 47, 5; P¼0.016) and 27 g per day
(95% CI: 54, 1; P¼0.041). The differences in protein, fibre
and carbohydrate intake are close to those estimated to be
observed based solely on intake of the lupin flour-enriched
food provided. Differences in energy, fat and alcohol intakes,
sodium and potassium excretion and physical activity at both
4 and 12 months were not significant (Table 3).
Body weight and composition
Body weight and body composition measurements were not
different between groups at baseline (Table 2). The baseline-
adjusted body weight and body composition measurements
in the control and lupin groups at 4 and 12 months and the
between-group differences are presented in Table 4. There
were no significant differences between treatment groups in
body weight, fat mass, fat-free mass, android and gynoid fat
percentages at 4 or 12 months. Furthermore, there were no
significant differences between treatment groups in the
maintenance of body weight loss (0.7 kg; 95% CI: 1.8,
0.5) and fat mass loss (0.4 kg; 95% CI: 1.4, 0.6) during the
weight maintenance period (from 4 to 12 months). Subgroup
analysis according to gender and baseline age (above and
below 50 years) and an intention-to-treat analysis did not
alter the interpretation of these results (data not shown).
Cardiovascular disease risk factors
Blood pressures, and fasting blood lipids, glucose and insulin
concentrations were not significantly different between
groups at baseline (Table 2). Baseline-adjusted blood pres-
sures, and fasting blood lipids, glucose and insulin concen-
trations at 4 and 12 months are presented in Table 5. For
lupin relative to control, mean 24-h systolic and diastolic
blood pressures were significantly lower at 12 months, but
not at 4 months. There were no differences between groups
in total cholesterol, low-density lipoprotein cholesterol,
Recruitment respondents:
screened by telephone
n ~ 800
Screened in-person
n = 231
Randomized
n = 134
Commenced trial
n = 131
(68 men, 63 women)
Control Group
Baseline
n = 63
(34 men, 29 women)
Lupin Group
Baseline
n = 68
(34 men, 34 women)
4 month assessment
n = 55
(32 men, 23 women)
4 month assessment
n = 55
(29 men, 26 women)
Completed trial
n = 47
(27 men, 20 women)
Completed trial
n = 46
(25 men, 21 women)
Withdrew
n = 8
Withdrew
n = 8
Withdrew
n = 13
Withdrew
n = 9
Withdrew prior to
baseline assessments
n = 3
Figure 1 Flowchart of participants at each stage of the trial.
Effects of lupin on body weight and CVD risk
R Belski et al
814
International Journal of Obesity
triglyceride and glucose concentrations at 4 and 12 months.
HDL cholesterol was significantly lower for lupin relative to
control. This difference was almost entirely because of an
increase from baseline to 12 months in HDL cholesterol
within the control group (0.07 (95% CI: 0.01, 0.13) mmol l
–1
,
P¼0.03), with no change within the lupin group (0.00
(95% CI: 0.06, 0.06) mmol l
–1
,P¼0.94). At both 4 and
12 months, the lupin group had significantly lower fasting
insulin concentrations and HOMA scores relative to
control (Figure 2). Subgroup analyses according to gender,
baseline body mass index (above and below 30 kg m
–2
) and
baseline total cholesterol (total cholesterol above and below
the median of 5.3 mmol l
–1
) and an intention-to-treat
analysis did not alter interpretation of these results (data
not shown).
Discussion
We have investigated the effects of 12 months of regular
consumption of a lupin-enriched diet, during and following
energy restriction, on body weight, body composition, and
cardiovascular disease risk factors in overweight and obese
men and women. The higher protein and fibre lupin-
enriched diet did not significantly influence body weight
and body fat and fasting total cholesterol and glucose
concentrations. However, the lupin-enriched diet resulted
in significantly lower fasting insulin concentrations by
16 and 21%, and HOMA scores by 30 and 33% at 4 and
12 months, respectively. We also found that the lupin-
enriched diet resulted in lower blood pressure at 12 months.
There is now strong evidence that increasing the protein
and fibre content of the diet can reduce appetite acutely.
2,3
In line with this, we have previously shown that increasing
the protein and fibre content of bread with lupin flour
significantly reduced appetite and energy intake acutely.
8
In
addition, lupin fibre-enriched foods have been shown to
increase satiety.
35
Data from studies using ad libitum diets
with increased protein
36–38
or fibre
3
intake are limited. We
recently reported that an ad libitum lupin flour-enriched diet
higher in dietary protein and fibre consumed over 4 months
did not significantly influence body weight or composition
in overweight individuals.
11
There is some evidence that
longer-term regular consumption of increased protein
36,37
Table 3 Mean energy and nutrient intakes, physical activity levels and urinary analytes of participants in the lupin and control groups at baseline, 4 and 12 months
a
Control Lupin
Baseline
(n¼63)
4 months
(n¼55)
12 months
(n¼47)
Baseline
(n¼68)
4 months
(n¼55)
12 months
(n¼46)
Energy intake (MJ per day) 9.8±2.5 7.9±1.7 8.3±2.4 9.9±2.5 8.0±1.9 8.2±2.2
Total fat intake (g per day) 92±30 63±21 66±29 96±32 69±27 69±27
Protein intake (g per day) 105±29 86±26 95±29 106±29 105±26 110±27
Carbohydrate intake (g per day) 236±83 208±53 218±64 230±68 182±49 191±55
Fibre intake (g per day) 24±826
±825
±723
±835
±839
±12
Alcohol (g per day) 15±17 11±16 11±17 20±21 10±13 9±13
24 h creatinine excretion (mmol per day) 14.0±5.0 14.4±5.4 16.8±11.9 13.5±3.4 13.9±3.7 14.7±4.5
Sodium excretion (mmol per mmol creatinine) 11.4±4.6 11.3±4.5 11.5±4.4 10.7±4.0 11.3±6.1 11.9±4.7
Potassium excretion (mmol per mmol creatinine) 5.8±1.8 5.7±1.9 5.7±2.3 5.7±1.7 6.2±2.6 5.7±1.6
Activity (kcal per kg per day) 40±744
±945
±941
±644
±11 45±7
a
Values are presented as mean±s.d.
Table 2 Characteristics of participants in the control and lupin groups at
baseline
a
Control (n¼63) Lupin (n¼68)
Men/women (n) 34/29 34/34
Age (years) 46.7±9.4
b
46.5±10.1
Height (m) 1.72±0.11 1.71±0.10
Activity (kcal per kg per day) 32.4±7.3 33.2±6.4
Body weight and composition
Body weight (kg) 93.7±15.2 91.8±13.5
BMI (kg m
–2
) 31.4±2.8 31.3±2.7
Body fat mass (kg) 34.7±7.3 34.1±7.2
Body fat (%) 39.3±7.7 39.1±7.3
Fat-free mass (kg) 57.5±13.3 56.6±11.6
Android fat (%) 48.3±6.3 47.7±6.7
Gynoid fat (%) 40.7±9.7 40.8±9.0
Blood pressure
24 h Systolic pressure (mm Hg) 121±10 122±9
24 h Diastolic pressure (mm Hg) 75±875
±7
Fasting biochemical assessments
Total cholesterol (mmol l
–1
) 5.33±0.84 5.18±0.84
LDL cholesterol (mmol l
–1
) 3.33±0.76 3.29±0.77
HDL cholesterol (mmol l
–1
) 1.34±0.27 1.33±0.28
Triglycerides (mmol l
–1
)
c
1.30 (1.18, 1.44)
c
1.12 (1.02, 1.23)
Glucose (mmol l
–1
) 5.03±0.51 5.11±0.45
Insulin (mU l
–1
)
c
7.83 (6.94, 8.83) 8.29 (7.28, 9.44)
HOMA-IR (units) 2.0±1.0 2.3±2.4
High-sensitivity C-reactive
protein (mg l
–1
)
2.93±4.37 2.93±3.27
Abbreviations: BMI, body mass index; HDL, high-density lipoprotein; HOMA-IR,
homeostasis model assessment of insulin resistance; LDL, low-density lipo-
protein.
a
Between-group differences analysed using the independent samples
t-test and the w
2
test for categorical variables. There were no significant
differences between groups for any of the variables reported.
b
Values are
presented as mean±s.d.
c
Geometric mean (95% confidence interval).
Effects of lupin on body weight and CVD risk
R Belski et al
815
International Journal of Obesity
or fibre
39
diets can assist weight loss with energy restriction
in overweight individuals. However, several intervention
studies have failed to demonstrate benefit.
We have shown that a lupin-enriched diet did not
significantly influence body weight, body fat mass or weight
regain. The lack of a significant between-group difference in
Table 4 Mean baseline-adjusted body weight and composition measurements and between-group differences of participants in the control and lupin groups
at 4 and 12 months
a
At 4 months At 12 months
Control (n¼55) Lupin (n¼55) Difference Control (n¼47) Lupin (n¼46) Difference
Mean (95% CI) Mean (95% CI) Mean (95% CI) Mean (95% CI) Mean (95% CI) Mean (95% CI)
Body weight (kg) 85.4 (84.5, 86.3) 85.5 (84.6, 86.4) 0.1 (1.2, 1.4) 85.8 (84.8, 86.8) 85.2 (84.2, 86.2) 0.6 (2.0, 0.8)
Body fat mass (kg) 29.5 (28.6, 30.3) 29.0 (28.1, 29.9) 0.5 (1.7, 0.7) 29.9 (28.9, 30.8) 28.9 (28.0, 29.9) 0.9 (2.2, 0.4)
Fat-free mass (kg) 55.7 (55.3, 56.2) 56.2 (55.8, 56.6) 0.5 (0.1, 1.1) 55.9 (55.5, 56.4) 56.1 (55.6, 56.6) 0.2 (0.5, 0.8)
Android fat (%) 43.7 (42.8, 44.7) 44.1 (43.1, 45.1) 0.4 (1.0, 1.7) 44.3 (43.3, 45.4) 44.0 (43.0, 45.1) 0.3 (1.8, 1.2)
Gynoid fat (%) 38.7 (38.0, 39.4) 38.4 (37.7, 39.1) 0.3 (1.3, 0.7) 38.7 (37.9, 39.4) 38.2 (37.5, 39.0) 0.5 (1.5, 0.6)
a
Values are baseline-adjusted mean or mean between-group difference (95% confidence intervals).
Table 5 Mean baseline-adjusted blood pressure, fasting biochemical measurements and between-group differences of participants in the control and lupin groups
at 4 and 12 months
a
At 4 months At 12 months
Control (n ¼55) Lupin (n¼55) Difference Control (n ¼47) Lupin (n¼46) Difference
Mean (95% CI) Mean (95% CI) Mean (95% CI) Mean (95% CI) Mean (95% CI) Mean (95% CI)
24 h Systolic ABPM (mm Hg) 118.5 (117.8, 119.2) 119.0 (118.4, 119.7) 0.51 (0.5, 1.5) 120.9 (120.1, 121.7) 119.6 (118.8, 120.3) 1.33 (2.4, 0.3)*
24 h Diastolic ABPM (mm Hg) 73.4 (72.9, 74.0) 73.6 (73.1, 74.1) 0.19 (0.6, 1.0) 74.3 (73.7, 74.9) 73.3 (72.7, 73.9) 1.0 (1.9, 0.2)*
Total cholesterol (mmoll
–1
) 5.03 (4.90, 5.16) 5.08 (4.95, 5.21) 0.05 (0.13, 0.24) 5.04 (4.90, 5.18) 5.08 (4.94, 5.22) 0.04 (0.16, 0.24)
LDL cholesterol (mmoll
–1
) 3.20 (3.09, 3.31) 3.23 (3.12, 3.34) 0.03 (0.12, 0.18) 3.18 (3.06, 3.30) 3.20 (3.09, 3.32) 0.03 (0.14, 0.19)
HDL cholesterol (mmoll
–1
) 1.39 (1.35, 1.42) 1.32 (1.28, 1.36) 0.06 (0.12, 0.01)* 1.42 (1.38, 1.46) 1.34 (1.29, 1.38) 0.08 (0.14, 0.02)*
Triglycerides (mmol l
–1
)
b
0.95 (0.89, 1.02) 1.03 (0.96, 1.11) 0.08 (0.02, 0.18) 0.96 (0.89, 1.04) 1.05 (0.97, 1.13) 0.08 (0.02, 0.19)
Glucose (mmol l
–1
) 5.12 (5.03, 5.21) 5.06 (4.97, 5.15) 0.05 (0.18, 0.07) 5.13 (5.03, 5.22) 5.08 (4.98, 5.18) 0.05 (0.18, 0.09)
Insulin (mU l
–1
)
b
7.18 (6.61, 7.81) 6.03 (5.54, 5.55) 1.19 (1.34, 1.06)* 7.56 (6.90, 8.28) 5.96 (5.44, 6.53) 1.27 (1.44, 1.11)*
HOMA-IR (units) 1.96 (1.68, 2.24) 1.37 (1.09, 1.66) 0.59 (0.99, 0.19)* 2.06 (1.75, 2.37) 1.39 (1.08, 1.70) 0.67 (1.11, 0.24)*
High-sensitivity CRP (mgl
–1
) 3.68 (2.80, 4.56) 3.12 (2.22, 4.01) 0.56 (1.82, 0.69) 2.71 (1.74, 3.68) 2.56 (1.60, 3.51) 0.15 (1.52, 1.21)
Abbreviations: ABPM, ambulatory blood pressure monitoring; CRP, C-reactive protein; HDL, high-density lipoprotein; HOMA-IR, homeostasis model assessment of
insulin resistance; LDL, low-density lipoprotein.
a
Values are baseline-adjusted mean or mean between-group difference (95% confidence intervals).
b
Geometric
mean (95% confidence interval). *Statistically significant (Po0.05).
04
12
5.4
5.2
5
4.8
4.6
4.4
0
HOMA- IR (units)
Glucose Concentration (mmol/L)
Months
0412
Months
Control
Lupin
0412
Months
2.3
2
1.9
1.8
1.7
1.6
0
2.2
2.1
2.4
Insulin Concentration (mU/L)
10.5
10
9.5
9
8
7
6.5
0
7.5
8.5
Figure 2 Glucose and insulin concentrations and HOMA scores at baseline, 4 months and 12 months for participants in the control (X) and lupin (O) groups.
Values presented are mean and s.e.m.
Effects of lupin on body weight and CVD risk
R Belski et al
816
International Journal of Obesity
body weight suggests that effects of lupin-enriched foods on
satiety may be, in part, counterbalanced by other dietary,
lifestyle and/or environmental factors that influence energy
balance in the longer term.
40
The observed differences in
body weight in our study were small (o1 kg). Although
effects of this magnitude may be important for long-term
maintenance of healthy body weight, our study was only
powered to detect a 2-kg body weight difference between the
groups. A recent meta-analysis suggests a small benefit of
higher protein diets on fat-free mass retention (B1.2 kg), but
not on body weight or fat loss.
4
The observed differences in
fat-free mass in the current study were not significant. The
difference in protein intake of 15–19 g per day in our trial
was modest compared with most previous trials in which
differences have usually been 430 g per day.
2
However, the
higher protein intake was concurrent with higher dietary
fibre intake (additional 9–14 g per day), which would be
regarded as considerable.
3
The total fibre intakes of
B35 g per day during weight loss and B39 g per day during
weight maintenance in the lupin group would also be
regarded as high and substantial enough to impact satiation
and satiety.
3
The type of fibre present in lupin may also be
important. Lupinus angustifolius, the species of lupin used in
these studies, contains B70% insoluble fibre.
41
Insoluble
fibre may be less effective than soluble fibre in reducing
appetite.
3
However, the results of this trial when taken
together with results of our previous trials
11,12
bring into
question the importance of acute effects of dietary nutrients
on appetite and energy intake for longer-term effects on
body weight and composition.
In the current study the lupin treatment resulted in a
significant reduction in fasting insulin concentrations and
HOMA scores following weight loss at 4 months. These
differences were maintained during weight maintenance to
12 months. In a recently published study, involving a similar
population of overweight men and women, we found that
4 months of regular consumption of an ad libitum lupin-
enriched diet did not alter fasting glucose or insulin
concentrations.
11
This suggests that weight loss in over-
weight individuals may be important to attain improve-
ments in insulin sensitivity with a lupin-enriched diet. If a
lupin-enriched diet can improve insulin sensitivity, the
components responsible remain uncertain. It is possible that
both the fibre and protein in lupin flour could contribute to
improved insulin sensitivity. We and others have previously
shown that lupin flour-enriched foods can acutely reduce
postprandial glycaemia and insulinaemia.
12,27
Such effects, if
maintained in the longer term, may contribute to improved
insulin sensitivity. Data from the Framingham Offspring
Cohort study suggest that an extra 14 g of dietary fibre per
day would improve HOMA scores by 0.6 units.
42
In the
present study the difference in fibre intake at 12 months was
14 g per day and the difference in HOMA score was 0.7 units.
Acutely, dietary protein enhances insulin secretion,
43,44
leading to increased glucose disposal. Although data from
epidemiological studies indicate that this may not result in
improved insulin sensitivity,
45,46
positive effects of higher
protein intakes have been observed in some intervention
studies.
21,47,48
The lack of effect on glucose concentrations
in the current study may be because of population selection.
All participants were non-diabetic and had otherwise
normal fasting glucose concentrations at screening of
o6.0 mmol l
–1
.
Regular consumption of lupin flour-enriched foods
resulted in lower systolic and diastolic blood pressure at
12 months, but not at 4 months. Available data suggest that
higher plant protein
15
and dietary fibre
17
intakes, and
substitution of carbohydrate in the diet with protein and
fibre can benefit blood pressure.
22
We previously showed
that 4 months of regular consumption of an ad libitum
lupin flour-enriched diet resulted in lower systolic blood
pressure by 3 mm Hg in overweight individuals.
22
The lack
of difference in systolic blood pressure at 4 months and
the estimated systolic blood pressure difference at 12 months
of 1.3 mm Hg indicates that weight loss resulting in lower
blood pressure may have obscured some of the effects of the
lupin flour-enriched diet. Another possible explanation of
the smaller observed effect size is that the lupin flour was
substituted primarily for wholemeal wheat flour. Most
previous trials have used a refined carbohydrate as the
control.
14–16,22
Limited data from human and animal studies suggest that
a lupin-enriched diet may benefit serum lipids and lipo-
protein.
24,49
However, we previously showed that an
ad libitum lupin flour-enriched diet over 4 months also had
no benefit on the serum lipid profile.
11
The lack of effect on
blood lipids in our studies may be because of a number of
factors. Most of our participants had normal lipid profiles at
baseline. Nevertheless, subgroup analyses in participants
with baseline total cholesterol above or below 5.3 mmol l
–1
(median) failed to show any between-group differences,
which is a result similar to our previous trial.
11
The lack of
changes in serum lipids may also be because of the physical
and structural characteristics of the lupin fibre, which is
primarily insoluble.
41
It is primarily soluble/viscous fibres
that have been found to significantly reduce total cholesterol
concentrations.
41
The findings of a significant increase in
HDL cholesterol from baseline to the end of intervention in
the control group, with no change in the lupin group, are
also consistent with our previous study.
11
The mechanism
for this is uncertain.
Our study was designed to investigate the functional
effects of 12 months of regular consumption of a lupin-
enriched diet. The study design did not allow demonstration
of the effect of lupin per se, independent from any generic
effects of increasing protein and fibre. However, the use of
lupin flour is a novel approach to increase the consumption
of both protein and fibre in significant amounts with a single
food ingredient. This may be more difficult using more than
one ingredient, or using selected high-protein and high-fibre
foods. In addition, most of the available evidence for
effects of protein and fibre on weight management and
Effects of lupin on body weight and CVD risk
R Belski et al
817
International Journal of Obesity
cardiovascular disease risk factors derives from studies
investigating these dietary components independently from
one another. The current study is therefore unique in
studying the functional effects of a higher protein and fibre
lupin-enriched diet, following both an energy-restricted
weight loss diet and an ad libitum weight maintenance diet.
In conclusion, regular consumption of lupin flour-
enriched foods during and following energy restriction did
not significantly influence body weight. The changes in
insulin concentrations and insulin sensitivity at 4 and 12
months indicate that even among non-diabetic individuals
with normal blood glucose levels, lupin flour-enriched foods
may improve insulin sensitivity in overweight individuals
when combined with weight loss. The observed effects
on blood pressure are consistent with a growing body of
evidence suggesting that diets higher in plant proteins and
dietary fibre lower blood pressure.
Conflict of interest
The authors declare no conflict of interest.
Acknowledgements
This study was funded by The Western Australian
Government, Department of Industry and Resources. We
thank Dr Kay Cox for her assistance with recommending
appropriate physical activity assessment tools. We also thank
Bodhi’s Bakery, Fremantle, WA, for baking the bread and
biscuits and Belmar Foods, Balcatta, WA, for manufacturing
and providing the pasta.
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Effects of lupin on body weight and CVD risk
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819
International Journal of Obesity
... Table 1 lists study locations and the species of lupin under investigation. Five studies recruited healthy men and women [15][16][17][18][19], three recruited healthy men only [20][21][22], four studies involved men and women with type 2 diabetes [23][24][25][26], five with hypercholesterolaemia [27][28][29][30][31] and four involved people who were overweight or obese [32][33][34][35]. The number of completing participants ranged from n = 5 to n = 175 per study. ...
... Eleven studies measured serum lipids refs. [19,22,23,25,[27][28][29][30][31]34,35], of which 64% had one or more positive outcomes (i.e., showed statistically significant within-study difference(s) from baseline and/or control in a direction considered optimal for good health, depending on the health marker tested). Three studies did not report differences in serum lipids [19,23,34], while one study reported reduced HDL cholesterol with other lipids unchanged [35]. ...
... [19,22,23,25,[27][28][29][30][31]34,35], of which 64% had one or more positive outcomes (i.e., showed statistically significant within-study difference(s) from baseline and/or control in a direction considered optimal for good health, depending on the health marker tested). Three studies did not report differences in serum lipids [19,23,34], while one study reported reduced HDL cholesterol with other lipids unchanged [35]. ...
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Lupins have a unique nutrient profile among legumes and may have beneficial health effects when included in the diet. The aim of this systematic review was to investigate the effects of lupin on a range of health outcome measures. Databases included MEDLINE, Embase and CINAHL, and focused on controlled intervention studies on healthy adults and those with chronic disease such as type 2 diabetes, cardiovascular disease and overweight. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocol was followed. Investigated intervention diets utilised whole lupin, lupin protein or lupin fibre, and outcomes were measured by markers of chronic disease, body weight and satiety. Quality assessment of results was performed using the Cochrane revised risk of bias tool. Overall, 21 studies with 998 participants were included: 12 using whole lupin, four used lupin protein and five lupin fibre. Beneficial changes were observed in 71% of studies that measured blood pressure, 83% measuring satiety and 64% measuring serum lipids. Unintended weight loss occurred in 25% of studies. Whole lupin demonstrated more consistent beneficial effects for satiety, glycaemic control and blood pressure than lupin protein or lupin fibre. Heterogeneity, low study numbers and a small participant base indicated further studies are required to strengthen current evidence particularly regarding the protein and dietary fibre components of lupin.
... Several studies investigated comparisons of dietary protein with fiber (two papers) [67,68], with fat (one paper) [69], or with no supplementation (no placebo used) (two papers) [70,71]. Several studies only compared effects of specific proteins (lupin, animal vs. vegetable protein and glycomacropeptide) and were included only in the secondary meta-analysis (three papers) [72][73][74]. See Table 2 and Supplementary Material Table S1 for information on study features and participant characteristics. ...
... In the six studies [33,36,51,[72][73][74] assessing different effects from specific proteins (whey protein vs. soy or casein, lupin flour vs. wheat flour, animal vs. vegetable protein, glycomacropeptide-enriched whey protein isolae vs. skim milk powder), no specific protein seemed to be superior compared to the matching controls. However, only one [72] of the six studies reported the estimated difference including the variance. ...
... In the six studies [33,36,51,[72][73][74] assessing different effects from specific proteins (whey protein vs. soy or casein, lupin flour vs. wheat flour, animal vs. vegetable protein, glycomacropeptide-enriched whey protein isolae vs. skim milk powder), no specific protein seemed to be superior compared to the matching controls. However, only one [72] of the six studies reported the estimated difference including the variance. Thereby, the variance was imputed for the remaining five studies, introducing a significant risk of bias. ...
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The primary aim was to systematically review the current evidence investigating if dietary interventions rich in protein lead to improved body weight management in adults with excessive body weight. The secondary aim was to investigate potential modifying effects of phenotyping. A systematic literature search in PubMed, Web of Science, and Cochrane Library identified 375 randomized controlled trials with 43 unique trials meeting the inclusion criteria. The Cochrane collaboration tool was used for a thorough risk of bias assessment. Based on 37 studies evaluating effects of dietary protein on body weight, the participants with increased protein intake (ranging from 18–59 energy percentage [E%]) were found to reduce body weight by 1.6 (1.2; 2.0) kg (mean [95% confidence interval]) compared to controls (isocaloric interventions with energy reduction introduced in certain studies). Individuals with prediabetes were found to benefit more from a diet high in protein compared to individuals with normoglycemia, as did individuals without the obesity risk allele (AA genotype) compared to individuals with the obesity risk alleles (AG and GG genotypes). Thus, diets rich in protein would seem to have a moderate beneficial effect on body weight management.
... No studies have been reported investigating the effect of LKF ingestion on blood pressure; however, several studies have shown beneficial effects on blood pressure from consumption of lupin kernel flour-containing foods in non-diabetic participants [64,65]. The authors hypothesised that the effect was due to the increased protein and fibre in the lupin flour-containing diet. ...
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The kernels (dehulled seeds) of lupins (Lupinus spp.) contain far higher dietary fibre levels than other legumes. This fibre is a complex mixture of non-starch polysaccharides making up the thickened cell walls of the kernel. The fibre has properties of both insoluble and soluble fibres. It is a major by-product of the manufacture of lupin protein isolates, which can be dried to produce a purified fibre food ingredient. Such an ingredient possesses a neutral odour and flavour, a smooth texture, and high water-binding and oil-binding properties. These properties allow its incorporation into foods with minimum reduction in their acceptability. The lupin kernel fibre (LKF) has demonstrated beneficial effects in clinical studies on biomarkers for metabolic diseases such as obesity, type 2 diabetes, and cardiovascular disease. It can be described as a “prebiotic fibre” since it improves gut micro-floral balance and the chemical environment within the colon. Thus, LKF is a health-functional ingredient with great opportunity for more widespread use in foods; however, it is evident that more non-thermal methods for the manufacture of lupin kernel fibre should be explored, including their effects on the physicochemical properties of the fibre and the effect on health outcomes in long term clinical trials.
... The hydrolysate alone improved some electrocardiographic parameters, decreased plasma activity of ACE and improved the kidney function, but also provided many synergistic effects with exercise [165]. Belski et al. reported that consuming a lupin-enriched diet over a period of 12 months can lower blood pressure and blood cholesterol concentrations as well as improve insulin sensitivity in human subjects [166]. ...
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Pulses and whole grains are considered staple foods that provide a significant amount of calories, fibre and protein, making them key food sources in a nutritionally balanced diet. Additionally , pulses and whole grains contain many bioactive compounds such as dietary fibre, resistant starch, phenolic compounds and mono-and polyunsaturated fatty acids that are known to combat chronic disease. Notably, recent research has demonstrated that protein derived from pulse and whole grain sources contains bioactive peptides that also possess disease-fighting properties. Mechanisms of action include inhibition or alteration of enzyme activities, vasodilatation, modulation of lipid metabolism and gut microbiome and oxidative stress reduction. Consumer demand for plant-based proteins has skyrocketed primarily based on the perceived health benefits and lower carbon footprint of consuming foods from plant sources versus animal. Therefore, more research should be invested in discovering the health-promoting effects that pulse and whole grain proteins have to offer.
... It has a high protein and fiber content (Erbas et al., 2005;Tizazu and Emire, 2010). It also has positive roles in combating obesity, diabetes, and cardiovascular disease (Magni et al., 2004;Belski et al., 2010;Duranti and Morazzoni, 2011). However, the extensive use of lupin for food or feed is hindered by its alkaloid content (Yeheyis et al., 2010). ...
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The genetic diversity in 48 lupin (Lupinus albus (L.) accessions collected from the Amhara region, Ethiopia, was assessed using seed storage protein markers (SDS-PAGE). A total of 30 different protein bands with sizes ranging from 11 to 100 kDa were detected. The average number of protein bands, the percentage of polymorphism, and gene diversity in the accessions were 16.96, 20.35, and 0.072, respectively. Genetic diversity estimates showed that West Gojam and Bahir Dar areas could be the most important sources for lupin genetic resources. The pair-wise comparison of genetic distances (GDs) among the accessions ranged from 0.011 to 0.378. The most distantly related accessions were accession 6, collected from the West Gojam zone, and accession 28 from the Bahir Dar area. Principal coordinate analysis (PCoA) showed the absence of a distinct group, and most of the accessions were intermixed. Population structure analysis revealed that the 48 lupin accessions could be assigned to three clusters. Similar to PCoA, no defined grouping based on geographic origin was observed. Accessions from different geographic origins being grouped together could be attributed to a common origin for the various accessions in the different zones, or it could be the result of seed-mediated gene flow among different lupin growing areas of the country.
Article
Lupin protein hydrolysates (LPHs) are gaining attention in the food and nutraceutical industries due to their several beneficial health effects. Recently, we have shown that LPH treatment reduces liver cholesterol and triglyceride levels in hypercholesterolemic mice. The aim of this study was to elucidate the effects of LPH treatment on the molecular mechanism underlying liver cholesterol metabolism in ApoE-/- mice fed the Western diet. After identifying the composition of the peptide within the LPH mixture and determining its ability to reduce HMGCoAR activity in vitro, its effect on the LDLR and PCSK9 pathways was measured in liver tissue from the same mice. Thus, the LPH reduced the protein levels of HMGCoAR and increased the phosphorylated inactive form of HMGCoAR and the pHMGCoAR/HMGCoAR ratio, which led to the deactivation of de novo cholesterol synthesis. Furthermore, the LPH decreased the protein levels of SREBP2, a key upstream transcription factor involved in the expression of HMGCoAR and LDLR. Consequently, LDLR protein levels decreased in the liver of LPH-treated animals. Interestingly, the LPH also increased the protein levels of pAMPK responsible for HMGCoAR phosphorylation. Furthermore, the LPH controlled the PSCK9 signal pathway by decreasing its transcription factor, the HNF1-α protein. Consequently, lower PSCK9 protein levels were found in the liver of LPH-treated mice. This is the first study elucidating the molecular mechanism at the basis of the hypocholesterolemic effects exerted by the LPH in an in vivo model. All these findings point out LPHs as a future lipid-lowering ingredient to develop new functional foods.
Chapter
Pulse proteins (PP) are gaining popularity as compared to animal proteins due to perceived sustainably, allergen-free, gluten-free, low cost and increasing vegan population. The post-translational processing and variations in agronomic as well as environmental factors caused variations in physicochemical and functional properties of PP. These proteins have lower digestibility that can be improved by hydrolyzing into peptides and amino acids. Though absorption and utilization of hydrolyzed protein products in the presence of anti-nutritional factors is reduced and mechanism is unrevealed. The amount of these factors can be reduced or eliminated by altering their biosynthesis pathways and adopting appropriate processing methods. Germination and fermentation of pulses reduce the content of antinutritional factors leading to improved protein digestibility. Emulsification properties of protein depend on the distinct amino acid order and composition as well as surface hydrophobicity. Efforts are also being made to improve functional properties such as emulsification, solubility etc. by forming Maillard conjugates. Undesirable beany odor in the pulses also restricts their applications in food products. The reduction in beany odor by fermenting pulses using appropriate microbial consortia has been suggested. Aquafaba, a viscous liquid from cooked pulses has potential to develop vegan products.
Chapter
Inflammation and oxidative stress-related metabolic disorders are on the genesis of several highly prevalent noncommunicable diseases, including cardiovascular diseases, which currently represent the leading cause of premature death worldwide. However, evidence suggests that healthy dietary habits may exert positive antiinflammatory and antioxidant effects by preventing the onset or modulating such chronic conditions. In this context, pulse-based functional foods and ingredients have emerged as versatile and convenient vehicles to promote higher nutritional intake with additional health benefits. In this chapter, we describe the potential use of pulses and their bioactive compounds in the development of functional foods and ingredients capable of modulating inflammation and oxidative stress, discussing challenges and opportunities for both the scientific community and food industry. The most promising bioactive compounds appear to comprise carbohydrates and nondigestible components, proteins and bioactive peptides, tocopherols and carotenoids, phytosterols, saponins, and polyphenols. Both the direct and indirect influences of these compounds over inflammation and oxidative stress-related health disorders have been reported. Nevertheless, the development of functional foods incorporating pulse-based ingredients poses several challenges. The largest difficulty relates to ensuring the sustenance of biologic activity throughout food supply chain and after consumption. More research regarding the optimization of growing and processing conditions that lead to better functional properties of pulses and pulse-based products is needed. Pulse flours, as well as their fiber and protein fractions, have become a convenient choice as pulse-based functional ingredients, mainly incorporated into baked products, providing important metabolic benefits. However, the bioavailability, efficacy and safety of pulse bioactive compounds require more thorough investigation, particularly during shelf-life periods. Also, since lentils, chickpeas, and beans have the highest concentrations of bioactive compounds (particularly their colorful cultivars), increased attention of researchers and food industry to these foods is justified. Lastly, more human controlled clinical trials testing the biological effects of pulse-based novel foods are required.
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There is a renewed interest on the reliance of food-based bioactive compounds as sources of nutritive factors and health-beneficial chemical compounds. Among these food components, several proteins from foods have been shown to promote health and wellness as seen in proteins such as α/γ-conglutins from the seeds of Lupinus species (Lupin), a genus of leguminous plant that are widely used in traditional medicine for treating chronic diseases. Lupin-derived peptides (LDPs) are increasingly being explored and they have been shown to possess multifunctional health improving properties. This paper discusses the intestinal transport, bioavailability and biological activities of LDPs, focusing on molecular mechanisms of action as reported in in vitro, cell culture, animal and human studies. The potentials of several LDPs to demonstrate multitarget mechanism of regulation of glucose and lipid metabolism, chemo- and osteoprotective properties, and antioxidant and anti-inflammatory activities position LDPs as good candidates for nutraceutical development for the prevention and management of medical conditions whose etiology are multifactorial.
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Previous studies comparing low-carbohydrate and low-fat diets have not included a comprehensive behavioral treatment, resulting in suboptimal weight loss. To evaluate the effects of 2-year treatment with a low-carbohydrate or low-fat diet, each of which was combined with a comprehensive lifestyle modification program. Randomized parallel-group trial. (ClinicalTrials.gov registration number: NCT00143936) 3 academic medical centers. 307 participants with a mean age of 45.5 years (SD, 9.7 years) and mean body mass index of 36.1 kg/m(2) (SD, 3.5 kg/m(2)). A low-carbohydrate diet, which consisted of limited carbohydrate intake (20 g/d for 3 months) in the form of low-glycemic index vegetables with unrestricted consumption of fat and protein. After 3 months, participants in the low-carbohydrate diet group increased their carbohydrate intake (5 g/d per wk) until a stable and desired weight was achieved. A low-fat diet consisted of limited energy intake (1200 to 1800 kcal/d; <or=30% calories from fat). Both diets were combined with comprehensive behavioral treatment. Weight at 2 years was the primary outcome. Secondary measures included weight at 3, 6, and 12 months and serum lipid concentrations, blood pressure, urinary ketones, symptoms, bone mineral density, and body composition throughout the study. Weight loss was approximately 11 kg (11%) at 1 year and 7 kg (7%) at 2 years. There were no differences in weight, body composition, or bone mineral density between the groups at any time point. During the first 6 months, the low-carbohydrate diet group had greater reductions in diastolic blood pressure, triglyceride levels, and very-low-density lipoprotein cholesterol levels, lesser reductions in low-density lipoprotein cholesterol levels, and more adverse symptoms than did the low-fat diet group. The low-carbohydrate diet group had greater increases in high-density lipoprotein cholesterol levels at all time points, approximating a 23% increase at 2 years. Intensive behavioral treatment was provided, patients with dyslipidemia and diabetes were excluded, and attrition at 2 years was high. Successful weight loss can be achieved with either a low-fat or low-carbohydrate diet when coupled with behavioral treatment. A low-carbohydrate diet is associated with favorable changes in cardiovascular disease risk factors at 2 years. National Institutes of Health.
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The design of dietary, metabolic, and intervention studies should reflect the meal patterning of free-living individuals, but this design has not been systematically reviewed recently. Our objective was to examine meal-patterning trends [meals and snacks, termed eating occasions (EOs)] in a sample of US children and adults. This was a nationally representative cross-sectional study of US data sets from 1977 to 1978, 1994 to 1998, and 2003 to 2006 in 28,404 children (2-18 y of age) and 36,846 adults (> or = 19 y of age). The main outcomes of interest included the number and size (energy/d) of meal and snack EOs, the composition (food or beverage) of each EO, and the time interval between each EO. The number of EOs increased over the previous 30 y among all ages. For adults and children, the change in the number of EOs from 1977 to 2006 was greatest for those in the 75th and 90th percentiles, although the mean number increased across all percentiles. Energy intake, particularly from snacking, increased for both groups in all percentiles of the distribution. The time between EOs decreased by 1 h for adults and children (to 3.0 and 3.5 h in 2003-2006, respectively). Overwhelmingly, meals consisted of both food and beverages, but the percentage of snacking occasions that consisted of beverages only increased considerably among children. US children and adults are consuming foods more frequently throughout the day than they did 30 y ago. Researchers undertaking future clinical, preload, and related food studies need to consider these marked shifts as they attempt to design their research to fit the reality of the eating patterns of free-living individuals.
Conference Paper
Objective: This ancillary study of PREMIER sought to determine the effects on insulin sensitivity of a comprehensive behavioral intervention for hypertension with and without the Dietary Approaches to Stop Hypertension (DASH) dietary pattern. Research design and methods: Participants were assigned to one of three nonpharmacologic interventions for blood pressure (group A, advice only; group B, established; and group C, established plus DASH). The established intervention included weight loss, reduced sodium intake, increased physical activity, and moderate alcohol intake; the DASH dietary pattern was added to the established intervention for those in group C. The DASH dietary pattern is high in fruits, vegetables, and low-fat dairy products while being lower in total fat, saturated fat, and cholesterol. It is abundant in nutrients such as magnesium, calcium, and protein, which have been associated with improved insulin sensitivity. Insulin sensitivity was measured at baseline and at 6 months using the frequently sampled intravenous glucose tolerance test with minimal model analysis. Results: Both intervention groups decreased total calories, percentage of calories from fat, and sodium intake to similar levels, with similar amounts of energy expenditure and weight loss. Covariate differences seen only in group C included increased intake of protein, potassium, calcium, and magnesium. Compared with control subjects, insulin sensitivity improved significantly only in group C, from 1.96 to 2.95 (P = 0.047). Group B did have a significant decrease in fasting insulin and glucose, but the changes in insulin sensitivity did not reach statistical significance when compared with control subjects. Conclusions: These results suggest that including the DASH dietary pattern as part of a comprehensive intervention for blood pressure control enhances insulin action beyond the effects of a comprehensive intervention that does not include DASH.
Article
Background: Previous studies comparing low-carbohydrate and low-fat diets have not included a comprehensive behavioral treatment, resulting in suboptimal weight loss. Objective: To evaluate the effects of 2-year treatment with a low-carbohydrate or low-fat diet, each of which was combined with a comprehensive lifestyle modification program. Design: Randomized parallel-group trial. (ClinicalTrials.gov registration number: NCT00143936) Setting: 3 academic medical centers. Patients: 307 participants with a mean age of 45.5 years (SD, 9.7 years) and mean body mass index of 36.1 kg/m(2) (SD, 3.5 kg/m(2)). Intervention: A low-carbohydrate diet, which consisted of limited carbohydrate intake (20 g/d for 3 months) in the form of low-glycemic index vegetables with unrestricted consumption of fat and protein. After 3 months, participants in the low-carbohydrate diet group increased their carbohydrate intake (5 g/d per wk) until a stable and desired weight was achieved. A low-fat diet consisted of limited energy intake (1200 to 1800 kcal/d; <or=30% calories from fat). Both diets were combined with comprehensive behavioral treatment. Measurements: Weight at 2 years was the primary outcome. Secondary measures included weight at 3, 6, and 12 months and serum lipid concentrations, blood pressure, urinary ketones, symptoms, bone mineral density, and body composition throughout the study. Results: Weight loss was approximately 11 kg (11%) at 1 year and 7 kg (7%) at 2 years. There were no differences in weight, body composition, or bone mineral density between the groups at any time point. During the first 6 months, the low-carbohydrate diet group had greater reductions in diastolic blood pressure, triglyceride levels, and very-low-density lipoprotein cholesterol levels, lesser reductions in low-density lipoprotein cholesterol levels, and more adverse symptoms than did the low-fat diet group. The low-carbohydrate diet group had greater increases in high-density lipoprotein cholesterol levels at all time points, approximating a 23% increase at 2 years. Limitation: Intensive behavioral treatment was provided, patients with dyslipidemia and diabetes were excluded, and attrition at 2 years was high. Conclusion: Successful weight loss can be achieved with either a low-fat or low-carbohydrate diet when coupled with behavioral treatment. A low-carbohydrate diet is associated with favorable changes in cardiovascular disease risk factors at 2 years. Primary funding source: National Institutes of Health.
Article
The hulls and cotyledons from three Western Australian cultivars (Gungurru, Yorrel and Danja) of Lupinus angustifolius, all of low alkaloid content, were analysed separately for their carbohydrate content and composition. Only minor differences in composition between these three cultivars were observed. More notably, the cotyledons of all the cultivars contained levels of non-starch polysaccharides (NSP), ranging from 290 to 310 g kg−1 dry weight considerably higher than had been measured previously in cultivars of this species. Galactose, arabinose and uronic acid residues accounted for approximately 67%, 13% and 10%, respectively, of the cotyledon NSP. Although only a small proportion of the cotyledon NSP is soluble, a much larger proportion could be extracted with hot EDTA treatment. The oligosaccharide content of the cotyledons ranged from 74 to 80 g kg−1 dry weight. Cotyledons had very low contents of cellulose, lignin and starch. Hulls consisted predominantly of NSP, with values ranging from 856 to 891 g kg−1 dry weight. Glucose, xylose, uronic acids and arabinose were the principal sugar residues present reflecting the compositions of the major constituent polysaccharides, cellulose, hemicelluloses and pectins. Only low levels of lignin were measured in hulls. Cotyledon NSP and hulls from these cultivars may have considerable value as sources of dietary fibre in the human diet.
Article
We previously have shown that ingested beef protein is just as potent as glucose in stimulating a rise in insulin concentration in type II diabetic patients. A synergistic effect was seen when given with glucose. Therefore, we considered it important to determine if other common dietary proteins also strongly stimulate an increase in insulin concentration when given with glucose. Seventeen type II (non-insulin-dependent) untreated diabetic subjects were given single breakfast meals consisting of 50 g glucose, or 50 g glucose plus 25 g protein in the form of lean beef, turkey, gelatin, egg white, cottage cheese, fish, or soy. The peripheral plasma concentrations of glucose, insulin, glucagon, alpha amino nitrogen, urea nitrogen, free fatty acids, and triglycerides were measured. Following ingestion of the meals containing protein, the plasma insulin concentration was increased further and remained elevated longer compared with the meal containing glucose alone. The relative area under the insulin response curve was greatest following ingestion of the meal containing cottage cheese (360%) and was least with egg white (190%) compared with that following glucose alone (100%). The glucose response was diminished following ingestion of the meals containing protein with the exception of the egg white meals. The peripheral glucagon concentration was decreased following ingestion of glucose alone and increased following all the meals containing protein. The alpha amino nitrogen concentration varied considerably. It was decreased after glucose alone, was unchanged after egg white ingestion, and was greatest after ingestion of gelatin. The free fatty acid concentration decrease was 4- to 8-fold greater after the ingestion of protein with glucose compared with ingestion of glucose alone.
Article
It is unclear whether low-carbohydrate, high-protein, weight-loss diets benefit body mass and composition beyond energy restriction alone. The objective was to use meta-regression to determine the effects of variations in protein and carbohydrate intakes on body mass and composition during energy restriction. English-language studies with a dietary intervention of > or =4200 kJ/d (1000 kcal/d), with a duration of > or =4 wk, and conducted in subjects aged > or =19 y were considered eligible for inclusion. A self-reported intake in conjunction with a biological marker of macronutrient intake was required as a minimum level of dietary control. A total of 87 studies comprising 165 intervention groups met the inclusion criteria. After control for energy intake, diets consisting of < or =35-41.4% energy from carbohydrate were associated with a 1.74 kg greater loss of body mass, a 0.69 kg greater loss of fat-free mass, a 1.29% greater loss in percentage body fat, and a 2.05 kg greater loss of fat mass than were diets with a higher percentage of energy from carbohydrate. In studies that were conducted for >12 wk, these differences increased to 6.56 kg, 1.74 kg, 3.55%, and 5.57 kg, respectively. Protein intakes of >1.05 g/kg were associated with 0.60 kg additional fat-free mass retention compared with diets with protein intakes < or =1.05 g/kg. In studies conducted for >12 wk, this difference increased to 1.21 kg. No significant effects of protein intake on loss of either body mass or fat mass were observed. Low-carbohydrate, high-protein diets favorably affect body mass and composition independent of energy intake, which in part supports the proposed metabolic advantage of these diets.