Weight Loss While Breastfeeding

You may wonder if you can return to your pre-pregnancy shape and weight after your baby’s birth. If you follow a reasonably well-balanced diet and eat in line with your appetite, you’ll probably lose some weight naturally in the next few months. Breastfeeding mothers tend to lose more weight than mothers who don’t breastfeed (La Leche League International, 2024; Smethers et al, 2023). Research shows that the impact of breastfeeding on weight loss is strongest in mothers who are overweight before pregnancy. (Smethers et al., 2023). You need fuel to make milk. Breastfeeding burns about 500-700 kcal (calories) or 2,100 – 2,900 kJ (kilojoules) per day. Some of this energy can come from stored body fat. However, this extra fuel burning may not always translate to weight loss after birth. Factors like type of delivery, physical activity level, and others can influence weight loss after birth (Dellapiana et al., 2024). It’s usually recommended that you wait at least six to eight weeks after birth before actively trying to lose weight. Your body is recovering from birth and getting used to making milk. If you have a concern about your individual  health issues, you may wish to consult with a healthcare provider about the safety of any changes in diet or exercise. Pregnancy weight wasn’t gained overnight so it may not disappear very quickly, either! A slow and steady weight loss of one pound (about half a kilogram) per week or four pounds (about 2 kilograms) per month is generally considered safe and sustainable (Academy of Nutrition and Dietetics, 2022). Combining exercise with reducing calories can be more effective for losing weight after birth than either alone (Dellapiana et al., 2024). You can start gentle movement soon after giving birth. It’s usually safe to start more vigorous exercise around 6-12 weeks  – check with your healthcare provider if you’re not sure. Work back into a routine gradually. Try a brisk walk with your baby, gentle yoga, swimming, or another favorite form of physical fitness to encourage your body to shed those extra pounds. Exercise is great for other aspects of health and fitness, too. Exercise doesn’t affect the volume, quality, or taste of your milk (Lauwers & Swisher, 2021; Campbell et al., 2024) – so have fun with it! For more information about exercise and breastfeeding see Exercise FAQ. The Art of Breastfeeding (9th edition, La Leche League International, 2024) has lots of tips on taking “microbreaks” for exercise (Chapter 14, pages. 391-2). Low carbohydrate diets such as the Atkins or Paleo methods are thought to be safe, as long as you eat a good variety of fruits, vegetables, proteins, and enough total calories (Lauwers & Swisher, 2021). Severe restriction of any macronutrient (such as protein, carbohydrates, or fats) is not recommended during breastfeeding (Hart et al, 2022). Some case studies suggest that very low-carb or strict “keto” diets while breastfeeding may result in serious medical effects such as lactational ketoacidosis (see glossary). In some of these cases the mothers’ bodies were under extra stress, for example from infection, very strenuous exercise, or nursing more than one child. All the mothers made a good recovery (de Amorim et al., 2024). However, it is best to check with a dietitian or healthcare provider if you’re considering one of these diets while breastfeeding. Intermittent fasting (IF) means eating only at certain times. For example, you might eat during an eight-hour “eating window” and then fast for 16 hours. Time-restricted eating is not recommended during breastfeeding (Hart et al., 2022). We don’t have enough information to know whether it’s safe. In theory, it could put you at risk of nutrition deficiencies. Instead, eating smaller, balanced meals more frequently throughout the day can help maintain your energy levels and prevent overeating (Campbell et al., 2024). For more information about fasting and breastfeeding see Fasting FAQ. Supplements, shakes, and similar items marketed for weight loss are not generally recommended during breastfeeding. They often haven’t been researched for use during breastfeeding and they’re not subject to the kind of quality control and safety regulation that medications are (Campbell et al., 2024). The use of prescription medications for weight loss is not recommended during the first year of breastfeeding. Oral weight loss medications are generally not recommended as they may enter milk and cause side effects in the baby, such as decreased appetite. Injectable medications are less likely to enter milk. However, they can cause nausea, vomiting, diarrhea, and very low calorie intake for the person taking the medication. This could reduce your milk production and affect the nutrients in your milk. If your baby is older than a year and eating plenty of family foods, this may be less of a concern. Research is ongoing about the use of weight loss medications during breastfeeding. Check with your healthcare provider about the safety of any medication you’re thinking of taking (Campbell et al., 2024). Weight loss during breastfeeding is possible and can be safe for both you and your baby. The keys are to eat a wide variety of nutritious foods, keep physically active, and follow gradual, safe weight loss practices. Macronutrient: Macronutrients are dietary components that your body needs in large amounts, namely protein, carbohydrates, and fats. Micronutrients, such as vitamins and minerals, are nutrients that are needed in smaller amounts. Nutrient-dense: Nutrient-dense foods provide a substantial amount of nutrients such as vitamins, minerals, protein, and healthy fats for the number of calories they contain. Foods that are not nutrient-dense tend to be higher in calories and less nutritiousLactational ketoacidosis: Lactational ketoacidosis is a rare health emergency usually related to very low carbohydrate and/or calorie consumption during lactation. This condition causes symptoms such as nausea, vomiting, malaise (general feeling of sickness), abdominal pain, and abnormal findings on blood and urine tests. Academy of Nutrition and Dietetics. (2022). Losing weight while breastfeeding. Eat Right. https://www.eatright.org/health/pregnancy/breastfeeding-and-formula/losing-weight-while-breastfeeding Campbell, N., Krutsch, K., & Garner, C.D. (2024) Weight loss in lactation. InfantRisk Center. https://www.infantrisk.com/content/weight-loss-lactation de Amorim, A. L. B., Rodrigues, E. F., Sussi, E. L., & Neri, L. C. L. (2024). Carbohydrate restriction during lactation: A systematic review. Nutrition research (New York, N.Y.), 125, 91–100. https://doi.org/10.1016/j.nutres.2024.02.007 Dellapiana, G., Nguyen, Q. T., & Naqvi, M. (2024). Navigating Postpartum weight loss: Evidence and interventions. Current Obstetrics and Gynecology Reports. https://doi.org/10.1007/s13669-024-00398-7 Hart, T. L., Petersen, K. S., & Kris-Etherton, P. M. (2022). Nutrition recommendations for a healthy pregnancy and lactation in women with overweight and obesity – strategies for weight loss before and after pregnancy. Fertility and Sterility, 118(3), 434–446. https://doi.org/10.1016/j.fertnstert.2022.07.027 La Leche League International. (2024). The Art of Breastfeeding (9th ed.). Penguin Random House. Lauwers, J. & Swisher, A. (2021). Counseling the Nursing Mother: A Lactation Consultant’s Guide. Burlington, MA: Jones & Bartlett Learning. Smethers, A. D., Trabulsi, J. C., Stallings, V. A., Papas, M. A., & Mennella, J. A. (2023). Factors Affecting BMI Changes in Mothers during the First Year Postpartum. Nutrients, 15(6), 1364. https://doi.org/10.3390/nu15061364 Updated November, 2024