Balancing exercise and food intake with lactation to promote post-partum weight loss.
ABSTRACT Excess weight gain during pregnancy and post-partum weight retention are risk factors for obesity. While many studies report average weight retained from pregnancy is only 0·5-3·0 kg; between 14 and 20% of women are 5 kg heavier at 6-18 months post-partum than they were before pregnancy. Among normal-weight women, lactation usually promotes weight loss to a moderate extent, but not among those with BMI≥35 kg/m2. While exercise and energy restriction may promote weight loss during lactation, their effect on milk volume and composition and, consequently, infant growth must be considered. The effect of exercise on lactation performance has been investigated. Moderate aerobic exercise of 45 min/d, 5 d/week improved cardiovascular fitness, plasma lipids and insulin response; however, it did not promote post-partum weight loss. Breast milk volume and composition were not affected. The effect of exercise with energy restriction in overweight women on the growth of their infants has also been studied. At 1 month post-partum, women restricted their energy intake by 2092 kJ/d and exercised 45 min/d, 4 d/week for 10 weeks. Women in the diet and exercise group lost more weight than the control group (4·8 (sd 1·7) kg v. 0·8 (sd 2·3) kg); however, there were no differences in infant growth. Based on the current evidence, it is recommended that once lactation is established, overweight women may restrict their energy intake by 2092 kJ/d and exercise aerobically 4 d/week to promote a weight loss of 0·5 kg/week.
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ABSTRACT: There are few studies on body composition and the effects of diet on weight postpartum women. The aim was to evaluate the body composition and bone parameters in lactating rats treated with diet containing flaxseed flour during postweaning period.Nutricion hospitalaria. 01/2014; 30(n02):366-371.
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ABSTRACT: For women of reproductive age, excessive gestational weight gain (GWG) and/or postpartum weight retention can increase the risk of obesity. This systematic review evaluates the effectiveness of lifestyle modification control trials that utilize exercise interventions, with or without dietary intervention, on weight loss among postpartum women. A search of randomized clinical trials (RCT) was performed using the follow databases and the bibliography of candidate studies: MEDLINE, Web of Science, EMBASE, CENTRAL/Cochrane and Physiotherapy Evidence Database (PEDro). English language RCT papers published up to October 31st, 2012 which present changes on maternal body weight from baseline to the end of exercise intervention were included. The primary meta-analysis examined the effect of exercise interventions, with or without complementary dietary intervention, on weight loss during the postpartum period compared to usual standard of care. Five subgroup analyses were performed to examine differences in study interventions and exercise modalities: duration of intervention, quality of study methodology, supervision of exercise intervention, exercise intervention goals used and the type of dietary intervention. In total 11 studies met eligibility criteria with 769 participants, 409 under intervention and 360 in the control group. The primary meta-analysis included all 11 studies and found a mean difference (MD) on weight loss of -2.57 kg (95% CI -3.66 to -1.47). The subgroup analysis demonstrated that the most effective interventions in reducing weight in postpartum women were exercise programs with objectively defined goals, such as the use of heart rate monitors or pedometer (MD of -4.09 kg -95% CI -4.94 to -3.25, I(2)=0%), and exercise combined with intensive dietary intervention (MD of -4.34 kg -95% CI -5.15 to -3.52, I(2)=0%). Thus, there is benefit from overall lifestyle interventions on weight loss in postpartum women and exercise plus intensive diet and objective targets are the most effective intervention strategies.International Journal of Obesity accepted article preview online, 19 September 2013. doi:10.1038/ijo.2013.183.International journal of obesity (2005) 09/2013; · 5.22 Impact Factor
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ABSTRACT: Background The postpartum period is a vulnerable time for excess weight retention, particularly for the increasing number of women who are overweight at the start of their pregnancy and subsequently find it difficult to lose additional weight gained during pregnancy. Although postpartum weight management interventions play an important role in breaking this potentially vicious cycle of weight gain, the effectiveness of such interventions in breastfeeding women remains unclear. Our aim was to systematically review the literature about the effectiveness of weight management interventions in breastfeeding women.Methods Seven electronic databases were searched for eligible papers. Intervention studies included were carried out exclusively in breastfeeding mothers, ≤2 years postpartum and with a body mass index greater than 18.5 kg/m2, with an outcome measure of change in weight and/or body composition.ResultsSix studies met the selection criteria, and were stratified according to the type of intervention and outcome measures. Despite considerable heterogeneity among studies, the dietary-based intervention studies appeared to be the most efficacious in promoting weight loss; however, few studies were tailored toward the needs of breastfeeding women.Conclusions Weight management interventions which include an energy-restricted diet may play a key role in successful postpartum weight loss for breastfeeding mothers.Birth 04/2014; · 2.93 Impact Factor
Proceedings of the Nutrition Society
A meeting of the Nutrition Society hosted by the Irish Section was held at the University of Ulster, Coleraine on 16–18 June 2010
Symposium on ‘Nutrition: getting the balance right in 2010’
Session 1: Balancing intake and output: food v. exercise
Balancing exercise and food intake with lactation to promote
post-partum weight loss
Nutrition Department, The University of North Carolina at Greensboro, PO Box 26170, Greensboro, NC 27402-6170, USA
Excess weight gain during pregnancy and post-partum weight retention are risk factors for
obesity. While many studies report average weight retained from pregnancy is only 0.5–3.0kg;
between 14 and 20% of women are 5kg heavier at 6–18 months post-partum than they were
before pregnancy. Among normal-weight women, lactation usually promotes weight loss to a
moderate extent, but not among those with BMI ‡ 35kg/m2. While exercise and energy
restriction may promote weight loss during lactation, their effect on milk volume and compo-
sition and, consequently, infant growth must be considered. The effect of exercise on lactation
performance has been investigated. Moderate aerobic exercise of 45min/d, 5d/week improved
cardiovascular fitness, plasma lipids and insulin response; however, it did not promote post-
partum weight loss. Breast milk volume and composition were not affected. The effect of
exercise with energy restriction in overweight women on the growth of their infants has also
been studied. At 1 month post-partum, women restricted their energy intake by 2092kJ/d and
exercised 45min/d, 4d/week for 10 weeks. Women in the diet and exercise group lost more
weight than the control group (4.8 (SD 1.7) kg v. 0.8 (SD 2.3) kg); however, there were no
differences in infant growth. Based on the current evidence, it is recommended that once
lactation is established, overweight women may restrict their energy intake by 2092kJ/d and
exercise aerobically 4d/week to promote a weight loss of 0.5kg/week.
Lactation: Post-partum weight loss: Energy restriction: Exercise
The prevalence of obesity is increasing among women in
their childbearing years. In 2007, the rate of overweight
and obesity among UK women aged 25–34 years was 44%
and increased to 58% in women aged 35–44 years(1).
Excessive weight gain during pregnancy and retention of
weight in the post-partum period are risk factors for obe-
sity in later life(2). Average post-partum weight retention,
defined as the difference in pre-pregnancy weight and
weight at 1-year post-partum, ranges from 0.5 to 3.0kg;
however, 14–20% of women retain more than 4.5kg one
year after childbirth(3). This paper will review research
findings on the role of lactation, exercise and diet on
reducing post-partum weight retention.
Rooney and Schauberger(2)examined weight change
among 540 women during pregnancy, 6 months post-
partum and then 5–10 years later. Average weight retention
at 6 months post-partum was 1.7kg. Average weight gain
was 6.3kg at long-term follow-up measurements. The sig-
nificant predictors of weight gain in the later years were
excessive weight gain during pregnancy, post-partum
weight retention, breastfeeding and exercise. Women with
no post-partum weight retention gained 2.4kg a decade
later, compared to 8.3kg among those who retained weight
gain during pregnancy. Women who breastfed for at least
12 weeks had the smallest weight gain in follow-up;
women who did not breastfeed had the largest gain.
Women who reported exercising in the post-partum period
gained less weight one decade later compared to those who
reported not exercising.
The energycost oflactation
2092kJ/d(4). This additional energy requirement may be
met by increasing energy intake, decreasing energy
Corresponding author: Professor Cheryl Lovelady, fax +1 336 334-4129, email email@example.com
Proceedings of the Nutrition Society (2011), 70, 181–184
gThe Author 2011First published online 24 February 2011
Proceedings of the Nutrition Society
expenditure and/or mobilising maternal fat stores. This
results in weight change during lactation being highly
variable among women. For example, some women may
gain weight during lactation due to increasing energy
intake beyond the requirement for breast milk production,
whereas others may lose weight because they did not
increase their energy intake and adipose stores were uti-
lised to support lactation. The UK recommendations for
the additional energy intake during lactation range from
1883 to 2385kJ/d, depending on the month post-partum(5).
The USA and Canada suggest an additional 1381kJ/d
during the first 6 months of lactation(4). This recommen-
dation is based on the energy content of milk (estimated to
be 2092kJ/d) minus the mobilisation of fat stores (esti-
mated to be 711kJ/d). It was assumed that women do not
change their energy expenditure from their pre-pregnancy
activities through the post-partum period. However, this
assumption may not be accurate among all lactating
women. Dewey et al.(6)measured energy expenditure (not
including the energy costs of breast milk) in fully breast-
feeding women and reported an increase of almost 837kJ/d
from 6 weeks to 12 weeks post-partum. These results
suggest that women may be very sedentary and spend a
larger amount of time sitting and nursing their infants in
the early weeks after childbirth. As infants become older
and feed less frequently, mothers may return to the same
activity level they had before pregnancy. This change in
energy expenditure may explain why many women do not
lose weight in the early months of breastfeeding.
Research on weight loss with lactation supports this
theory. When reviewing the literature on breastfeeding and
post-partum weight retention, the majority of studies only
show a significant relationship when women breastfeed
fully for at least 6 months post-partum. Baker et al.(7)
reviewed weight changes in 36030 Danish women and
estimated that women lost 0.06–0.09kg for every week of
full breastfeeding. However, breastfeeding was negatively
associated with post-partum weight retention only in
women with BMI<35kg/m2. Krause et al.(8)reported
similar results among 14330 low-income, racially diverse
women in the USA. There was no association between
breastfeeding and post-partum weight retention at 3
months post-partum. However, at 6 months post-partum,
weight retention was 1.38kg lower in women who fully
breastfed and 0.84kg lower in women who combined
breastfeeding with formula, compared to women who only
formula fed their infants. Both studies controlled for other
factors affecting post-partum weight loss such as maternal
age, pre-pregnant BMI, gestational weight gain, ethnicity
and marital status and still found these significant rela-
tionships with breastfeeding and post-partum weight loss.
While these recent, large epidemiological studies report
that breastfeeding is positively related to post-partum
weight loss, the effect is small. In addition to breastfeed-
ing, diet and physical activity need to be considered in
recommendations for post-partum weight loss. However,
the effects of exercise and reduced energy intake on breast
milk volume and composition, and consequently infant
growth and health, must be considered.
The first intervention trial on the effects of aerobic
exercise in fully breastfeeding women was reported by
Dewey et al.(6). At 6 weeks post-partum, sedentary women
were randomised to either an exercise group, which con-
sisted of brisk walking at 60–70% of maximum heart rate
for 45min/d, 5d/week, for 12 weeks; or a control group
who remained sedentary. The duration of the initial session
was 20min; with subsequent sessions increasing by 5min
every 3d until 45min/d was achieved. Research assistants
travelled to participants’ homes and monitored the exercise
sessions. There were no dietary restrictions and women in
both groups were advised not to change their eating habits.
There was no significant difference in weight loss
between groups after the 12-week study. Both groups lost
an average of 1.6kg, which was predominantly fat mass.
Participants were expending an average of 1761kJ in their
45min exercise session. However, they compensated for
this by increasing their energy intake. The reported daily
energy intake of the exercise group was 1377kJ higher
than the control group at the end of the intervention. This
resulted in a similar energy deficit and weight loss among
exercising and sedentary women. Yet, the exercise group
significantly improved their insulin response to a test meal,
cardiovascular fitness, and HDL cholesterol levels more
than the control group(9). Breast milk volume and compo-
sition was not different between exercising and sedentary
Lovelady et al.(10)investigated the addition of energy
restriction to the same exercise protocol to examine the
effects of weight loss in overweight, lactating women on
the growth of their infants. Sedentary (defined as engaging
in exercise no more than once per week during the
Table 1. Body composition, cardiovascular fitness level and energy
intake before and after the intervention in the diet-and-exercise
and control (Data from reference 10) groups (Mean values and
BaselineEnd of study Change
Body fat (% weight)
Fat mass (kg)
Fat-free mass (kg)
Cardiovascular fitness (VO2ml/kg/min)
Energy intake (kJ/d)
- 2276 1971
- 987 2125
*Significantly different from the control group, P<0.01.
†Significantly different from the control group, P<0.05.
Proceedings of the Nutrition Society
previous 3 months), fully breastfeeding women were
randomised at 4 weeks post-partum to either restrict energy
intake by 2092kJ/d and exercise aerobically for 45min/d
(diet-and-exercise group), 4d/week; or to maintain their
usual dietary intake and not exercise (control group). Energy
requirement for lactation was estimated for each partici-
pant, using the Harris–Benedict equation; which considers
age, weight and height and activity level. A moderate level
activity factor was used in the equation. Additional energy
(2636kJ) was added to cover the needs for lactation.
The prescription for energy intake for weight loss was
determined by subtracting 2092kJ from this estimated
energy requirement. No participant was prescribed a diet of
less than 7531kJ/d. After the 10-week intervention, the
diet-and-exercise group lost an average of 4.8 (SD 1.7) kg
(primarily fat mass) compared to 0.8 (SD 2.3) kg in the
control group (Table 1). Ten of the twenty-one women in
the diet-and-exercise group (48%) compared to four of the
nineteen women in the control group (21%) were within
1kg of their pre-pregnancy weight at the end of the study.
Cardiovascular fitness improved an average of 13% in the
diet-and-exercise group compared to an increase of 2% in
the control group. Women in the diet-and-exercise group
significantly decreased their intake of fats, sweetened
drinks, sweets and desserts, and snack foods such as chips
compared to the control group(11). Average energy intake
and percentage of energy from fat at the end of the study
was significantly lower in the diet-and exercise group
(diet-and-exercise = 6983 (SD 1226) kJ, 23.5 (SD 5.2)% v.
control = 8962 (SD 2259) kJ, 31.4 (SD 3.6)%). Gain in
infant weight and length were similar in both groups.
Lovelady et al.(12)recently reported results on the
effects of aerobic and resistance training on body compo-
sition in fully breastfeeding women. At 4 weeks post-
partum, women were randomly assigned to either an
intervention consisting of aerobic exercise 3d/week and
resistance exercise 3d/week or to a sedentary group. The
resistance programme was conducted in the home of the
participants, supervised by a research assistant. Participants
used handheld adjustable weights and stability balls to
perform squats, bench presses, standing military presses,
stiff-leg dead lifts, high pulls, pushups, bent-over dumbbell
rows, wall sits, abdominal planks and abdominal crunches.
The aerobic portion consisted of brisk walking, following
the protocol described in the previous studies. Participants
in both groups were asked not to change their dietary
intake during the study.
Both groups lost approximately 3.6kg during the
16-week study. The control group decreased their energy
intake by an average of 1766kJ compared to the exercise
group’s decrease of 782kJ. The combination of increased
energy expenditure and decreased energy intake in the
exercise group was probably similar to the energy deficit of
only reduced energy intake in the control women, resulting
in the same weight loss between groups. The exercise
group increased their strength and endurance by 34–221%
for all exercises compared to changes of - 5.7% to 12% in
the control group. Cardiovascular fitness increased by
11.4% in the exercise group v. 6.9% in the control group;
however, this difference was not significant. Infant weight
gain and growth were similar in both groups.
The results of these intervention studies suggest that
exercise alone, without energy restriction does not promote
weight loss in lactating women. Exercise sessions were
monitored by research assistants and compliance was high
in all three studies. While average weight loss was not
different from sedentary participants; aerobic exercise
improved plasma lipids, insulin response to a test meal
and cardiovascular fitness. Resistance exercise increased
muscular strength and endurance.
Recent epidemiological studies suggest that full breast-
feeding for at least 6 months promotes post-partum weight
loss in women with BMI<35kg/m2. Yet, some women
may need to add exercise and dietary energy restriction to
enhance weight loss in the post-partum period and reduce
the risk of obesity in later life. Once lactation is estab-
lished, overweight and obese women may restrict their
energy intake by 2092kJ/d to promote a weight loss of
0.5kg/week. Research suggests that this rate of weight loss
will not affect infant growth. In conclusion, exercise alone,
without energy restriction does not promote post-partum
weight loss. Instead, full breastfeeding for at least
6 months post-partum, and energy restriction with aerobic
exercise, may be a successful strategy to promote post-
partum weight loss.
The author declares no conflicts of interest. The author’s
work was funded by the National Institutes of Health and
the North Carolina Agricultural Research Service. The
author thanks Grainne O’Higgins and Deborah West for
their assistance in preparation of the manuscript.
1. National Health Service Information Centre for Health
and Social Care (2008) Health Survey for England 2007.
2. Rooney BL & Schauberger CW (2002) Excess pregnancy
weight gain and long-term obesity: One decade later. Obstet
Gynecol 100, 245–252.
3. Gunderson EP, Abrams B & Selvin S (2000) The relative
importance of gestational gain and maternal characteristics
associated with the risk of becoming overweight after preg-
nancy. Int J Obesity 24, 1660–1668.
4. Institute of Medicine (2002) Dietary Reference Intakes for
Energy, Carbohydrate, Fiber, Fatty Acids, Cholesterol, Pro-
tein, Amino Acids (Macronutrients). Washington, DC:
National Academies Press.
5. Scientific Advisory Committee on Nutrition (2002) Key
Dietary Recommendations. http://www.food.gov.uk/science/
6. Dewey KG, Lovelady CA, Nommsen-Rivers LA et al. (1994)
A randomized study of the effects of aerobic exercise by
lactating women on breast-milk volume and composition.
N Engl J Med 330, 449–453.
7. Baker JL, Gamborg M, Heitmann BL et al. (2008) Breast-
feeding reduces postpartum weight retention. Am J Clin Nutr
8. Krause KM, Lovelady CA, Chowdhury N et al. (2010) The
effect of breastfeeding on postpartum weight retention: Data
from the North Carolina WIC programme. Pub Health Nutr.
Exercise and energy restriction during lactation 183
Proceedings of the Nutrition Society
9. Lovelady CA, Nommsen-Rivers LA, McCrory MA et al.
(1995) Effects of exercise on plasma lipids and metabolism
of lactating women. Med Sci Sports Exerc 27, 22–28.
10. Lovelady CA, Garner KE, Moreno KL et al. (2000) The
effect of weight loss in overweight, lactating women on the
growth of their infants. N Eng J Med 342, 449–453.
11. Lovelady CA, Garner KE, Moreno KL et al. (2006) The
effects of dieting on food and nutrient intake of lactating
women. J Am Diet Assoc 106, 908–912.
12. Lovelady CA, Bopp MJ, Colleran HL et al. (2009) Effect of
exercise training on loss of bone mineral density during lac-
tation. Med Sci Sports Exer 41, 1902–1907.
184 C. Lovelady