One study has suggested that short term weight loss of 2. Decrease the calories gradually. A sudden drop in calories can reduce milk supply. Some moms notice this during an illness, although dehydration andor medication use could also be a factor in reduced milk supply when mom is sick. It has been hypothesized that a sudden calorie decrease can cause moms body to go into starvation mode and cut nonessential resources such as milk production. Avoid quick fix solutions. Liquid diets, low carb diets, fad diets, weight loss medication, etc. What might happen if a nursing mother loses weight too quickly In most instances of too rapid weight loss, it is not the breastmilk composition or supply that would suffer, but moms nutrition andor health. Excessive dieting can result in a reduced milk supply. According to Breastfeeding and Human Lactation 3rd Edition, Riordan, pp 4. I was unable to find a definition of severely restricted but I expect that it is significantly under 1. Ive included information on a study on this subject below. See also the info at this website regarding environmental contaminants and breastfeeding. Three great tips for weight loss whether you are nursing or not Make dietary changes decrease your fat intake to 2. Recommended Intake of protein for nursing mothers is 6. Spread your calorie intake out instead of 2 3 meals, eat 3 smaller meals with snacks between. Your body will be less likely to go into starvation mode if you are eating small amounts throughout the day. Twice Baked Potatoes With Ground Beef. Exercise moderately so that you burn more fat while keeping lean muscle mass. Resistanceweight training is a good way to build muscle mass. A person with more muscle mass burns more calories, even when resting. Specific weight loss methods. Weight Watchers, Body for Life. Weight Watchers and Body for Life are generally considered to be fine for breastfeeding mothers. Weight Watchers has a program specifically aimed at nursing mothers. As always, avoid cutting calories too abruptly or losing weight too quickly. South Beach Diet, Atkins Diet. See Low carb diets and breastfeeding. Herbal weight loss products. See Herbal weight loss products and breastfeeding. Additional information other websites. Books. Research. Lovelady CA, et al. Weight change during lactation does not alter the concentrations of chlorinated organic contaminants in breast milk of women with low exposure. J Hum Lact 1. 99. Dec 1. 54 3. 07 1. The results of this study suggest that moderate weight loss 4. Mc. Crory MA. Does dieting during lactation put infant growth at risk Nutr Rev 2. Jan 5. Pt 1 1. 8 2. For some women, postpartum retention of weight gained during pregnancy may contribute to obesity. A recent 1. 0 week randomized intervention showed that infants of initially overweight, lactating mothers who exercised and dieted to lose an average of 0. Lovelady CA, et al. The effect of weight loss in overweight, lactating women on the growth of their infants. N Engl J Med 2. 00. Feb 1. 7 3. 427 4. This study found that weight loss of approximately 0. Mc. Crory MA, et al. Randomized trial of the short term effects of dieting compared with dieting plus aerobic exercise on lactation performance link is to full article. Am J Clin Nutr 1. May 6. 95 9. 59 6. This study found that short term weight loss approximately 1 kg2. Longer term studies are needed to confirm these findings. Dewey KG. Effects of maternal caloric restriction and exercise during lactation link is to full article. J Nutr 1. 99. 8 Feb 1. Suppl 3. 86. S 3. S. Studies suggest that, for women who are not underweight initially, lactation is not adversely affected by moderate rates of weight loss no more than 2 kg4. A short period of more rapid weight loss is not harmful to lactation. It is unknown, however, whether there are risks associated with longer periods of rapid weight loss. Journal search on dieting and exercise during lactation.