Losing weight is a concern for many mothers after the birth of a baby. Mothers may ask if it is possible to lose weight and breastfeed. During pregnancy, women gain extra pounds to store energy for producing breast milk. For some women, breastfeeding makes it easier to lose weight, since additional calories are used. Mothers who do not breastfeed will need to rely totally on diet and exercise to burn additional calories.
Dr. Judith Roepke, a nutritionist at Ball State University in Indiana and a member of LLLI’s Health Advisory Council, feels that the ideal time to lose weight is during lactation. Dr. Roepke suggests that breastfeeding mothers should not consciously try to lose weight during the first two months postpartum. This extra time in the early months allows a mother’s body to recover from childbirth and establish a good milk supply. It’s common for mothers to lose weight during this period by just following a normal diet and eating to hunger. One study showed that breastfeeding mothers tend to lose more weight when their babies are three to six months old than mothers who are bottle-feeding and consuming fewer calories.

The Subcommittee on Nutrition During Lactation reports:

“On average, lactating women who eat to appetite lose weight at the rate of 0.6 to 0.8 kg (1.3 to 1.6 pounds) per month in the first 4 to 6 months, but there is a wide variation in the weight loss experience of lactating women (some women gain weight during lactation). Those who continue breastfeeding beyond 4 to 6 months ordinarily continue to lose weight, but at a slower rate than during the first 4 to 6 months.”

If a mother gains weight or has stopped losing weight after the first two months, she can increase her activity level and reduce her intake by 100 calories per day. Although mothers reducing their caloric intake by 25% safely lost about one pound (.45 kg) per week without affecting their baby’s growth, according to a study by Dusdieker, nursing mothers need at least 1800 calories per day. Diets of less than 1500 calories per day are not recommended, although fasts of less than one day have not been shown to decrease milk volume.

A review article published in 1996 confirmed that exclusively breastfeeding mothers showed a greater loss of weight with a decrease in the percentage of body fat as well as hip and lower thigh circumference at three months postpartum than mothers who were bottle- feeding or partially breastfeeding.

Crash diets, fad diets and rapid weight loss present problems for breastfeeding mothers. Environmental contaminants including PCBs and pesticides are stored in body fat. Losing weight rapidly can release these contaminants into the mother’s bloodstream quickly and it was once thought that this would increase contaminant levels in her milk. Research brought to our attention after the BREASTFEEDING ANSWER BOOK was published does not demonstrate a significant increase.

It is suggested that mothers limiting their caloric intake pay special attention to eating a balanced and varied diet, including foods rich in calcium, zinc, magnesium, vitamin B6 and folate. If adequate dietary requirements are not met, calcium, multivitamin and mineral supplements may be needed. Weight loss medications and liquid diets are not recommended for breastfeeding mothers.

If a mother has a history of anorexia, bulimia or other eating disorder, she can still successfully breastfeed her baby. However, some women with a history of eating disorders experience a worsening of symptoms after birth. If a mother is suffering from an eating disorder, suggest she seek nutritional guidance as well as help in overcoming her eating problem.

Some mothers are concerned that exercise may interfere with milk production or that slightly elevated levels of lactic acid after exercise could cause negative reactions in their nursing babies. Studies have shown that exercise has little effect on breast milk. In fact, one study by Lovelady showed exercising women having a slightly higher milk volume.

Although wide publicity was given to a study which suggested that babies were less accepting of post-exercise breast milk, after reviewing this and other studies, Dewey and McCrory concluded that “altered acceptance of breast milk due to higher lactic acid concentrations post-exercise is not likely to be a problem in most cases.”

A combination of reasonable calorie reduction and regular moderate exercise will not only help a breastfeeding mother lose weight after the birth of her baby, but will also provide cardiovascular fitness.


  • Bowles, B. et al. Pregnancy and lactation following anorexia and bulimia. JOGNN 1990; 19(3):243-48.
  • Dewey, K. and McCrory, M. Effects of dieting and physical activity on pregnancy and lactation. Am J Clin Nutr 1994; 59(Suppl.): 446S-59S
  • Dusdieker, L. et al. Is milk production impaired by dieting during lactation? Am J Clin Nutr 1994; 59:833-40.
  • Hammer, R. et al. Low fat diet and exercise in obese lactating women. Breastfeed Rev 1996;4(1):29-34.
  • Heinig, M. et al. Lactation and postpartum weight loss. Mechanisms Regulating Lactation and Infant Nutrient Utilizations 1992;30:397-400.
  • Kramer, F. et al. Breastfeeding reduces maternal lower-body fat J Am Diet Assoc 1993;93(4):429-33.
  • Lovelady, C. et al. Lactation performance of exercising women. Am J Clin Nutr 1990; 52: 103-1.
  • Mohrbacher, N. and Stock, J. BREASTFEEDING ANSWER BOOK. Schaumburg, Illinois, USA; LLLI 1997; 371-86.
  • Mussalo-Rauhamaa, H. et al. Relation between the content of organochlorine compounds in Finnish human milk and characteristics of the mother. J Tox Envir Hlth 1988;25(1):1-10.
  • Subcommittee on Nutrition during Lactation, Food and Nutrition Board, Institute of Medicine, National Academy of Sciences, Nutrition During Lactation Washington, DC: National Academy Press, 1991 p.15, 74, 140.
  • Weekly, S. Diets and eating disorders: implications for the breastfeeding mother. NAACOG Clin Issues Perinat Women Health Nurs 1992; 3(4):695-700.

Last updated January 10, 2010 by jsa.

Mel Wolk, St. Peters, Missouri, USA
From: LEAVEN, Vol. 33 No. 5, October-November 1997, p. 115

We provide articles from our publications from previous years for reference for our Leaders and members. Readers are cautioned to remember that research and medical information change over time
Ed. Note: This article highlights information on weight loss while breastfeeding featured in the 1997 revision of the BREASTFEEDING ANSWER BOOK and THE WOMANLY ART OF BREASTFEEDING. Leaders will want to check both of these resources for more information on nutrition for breastfeeding mothers.