From the Guidelines
Breastfeeding women tend to lose 0.5-1.0 kg/month after the first postpartum month, which is a significant difference in weight loss compared to non-lactating women, due to the increased energy expenditure of approximately 500 extra calories daily required for milk production 1.
Key Factors Influencing Weight Loss
- The energy content of human milk, which is approximately 0.62 kcal/g (2.6 kJ/g), with the main source of energy being fat 1
- The total volume of milk produced by a mother, which is nearly 780 mL/day, resulting in an energy expenditure of 60-70 kcal/100 mL 1
- Maternal factors, such as pregnancy duration, and child characteristics, which can affect human milk energy content 1
- The importance of a balanced diet, with breastfeeding mothers requiring approximately 500 more kcal/day than non-pregnant women, to support milk production and weight loss 1
Comparison with Non-Lactating Women
- Non-lactating women may need to rely more on calorie restriction and exercise to achieve weight loss, aiming for a 500-calorie daily deficit through diet and physical activity
- Breastfeeding women, on the other hand, can benefit from the increased energy expenditure of milk production, as well as hormonal changes that help contract the uterus and potentially reduce abdominal fat 1
Recommendations for Breastfeeding Women
- Combine breastfeeding with a nutritious diet of about 1800-2200 calories daily, avoiding dropping below 1500-1800 calories to maintain milk supply
- Gradually introduce exercise starting 6-8 weeks postpartum, with healthcare provider approval
- Stay hydrated with 8-10 glasses of water daily, and aim for sufficient sleep when possible
- Monitor weight loss progress and adjust diet and exercise habits as needed to achieve a healthy weight loss of 0.5-1.0 kg/month 1
From the Research
Weight Loss in Lactating and Non-Lactating Women
- The difference in weight loss between lactating and non-lactating women is influenced by various factors, including energy balance, dietary intake, and physical activity 2, 3.
- Lactating women have additional energy needs, approximately 670 kcal/day, to support milk production, and a gradual weight loss of less than 2 kg/month is considered safe and does not adversely affect lactation 2, 3.
- Exercise, particularly aerobic exercise, can enhance cardiovascular fitness and maintain lean body mass, but it is not likely to increase the rate of weight loss unless dietary intake is controlled 2.
- Maternal plasma prolactin concentration increases under conditions of negative energy balance, which may serve to protect lactation 2.
Comparison of Weight Loss
- A study found that lactating women who fully breastfed for 3-6 months and ≥6 months had lower postpartum weight retention compared to those who fully breastfed for 1-3 months 4.
- The adjusted means for weight retention among mothers who fully breastfed for 1-3 months, 3-6 months, and ≥6 months were 3.40 ± 1.16 kg, 1.41 ± 0.69 kg, and 0.97 ± 0.32 kg, respectively 4.
- However, the difference in weight retention between those who reported full breastfeeding for 3-6 months and ≥6 months was not significant from 3 to 6 months postpartum 4.
Factors Influencing Weight Loss
- Maternal weight status, diet, and supplement use can influence breastfeeding and complementary feeding practices, with obese women having a higher risk of failure to initiate breastfeeding and delayed onset of lactogenesis 5.
- Prevention of obesity in women of reproductive age and counseling of obese women after delivery may be targeted to improve infant feeding practices 5.