Most women lose weight while breastfeeding with little or no effort. In fact, according to the breastfeeding advocacy organization La Leche League International, breastfeeding mothers burn 200 to 500 extra calories per day. Nevertheless, some new mothers need to follow calorie-restricted diets to help shed weight gained during pregnancy. When used appropriately, reduced-calorie diets can help nursing women lose weight without posing any risk to the health of the mother or breastfed child.
Function
According to La Leche League International, the body stores extra fat during pregnancy for the sole purpose of providing energy for breastmilk production. Even without following a consciously calorie-restricted diet, most women experience weight loss as a natural outcome of lactation. However, a calorie-restricted diet can speed the process of weight loss and enable a new mother to return to her pre-pregnancy weight with greater ease. Regardless of calorie intake, breastfeeding mothers should emphasize a balanced diet containing minimally processed foods and an adequate intake of vitamins, minerals and macronutrients.
Time Frame
Renowned lactation expert Kelly Bonyata recommends that women avoid restricting their calorie intake until two months after the baby's birth. After eight weeks, a nursing mother's breastmilk supply is well-established; dieting after this point will not generally affect supply. Most breastfeeding women experience peak weight loss between four to six months after giving birth, but weight loss will usually continue throughout the duration of breastfeeding. Women who practice sustained breastfeeding---beyond the first year---tend to lose more weight than those who wean their children during infancy.
Risks
In some cases, extreme dieting during lactation can negatively affect the health of the mother or the breastfed child. While La Leche League International states that one-day fasts have not been demonstrated to decrease breast milk supply, Kelly Bonyata warns that a sudden drop in calorie intake may decrease milk supply, particularly during the early stages of lactation. Most risks associated with dieting concern the health of the mother, rather than the child---an inadequate diet could cause nutritional deficiencies for the mother, leading to anemia, fatigue or depression.
Considerations
Precautions can prevent diet-related complications for breastfeeding mothers. Kelly Bonyata and La Leche League International both advise that nursing women consume at least 1,500 calories per day; some women may require 1,800 calories or more to meet their minimum nutritional requirements. Additionally, experts recommend against the use of crash diets, liquid diets and weight loss supplements for women who are nursing. These can adversely affect a mother's health and cause serious problems for the baby. Women with a history of anorexia nervosa may experience a relapse after giving birth and should follow reduced-calorie diets only under an expert's supervision.
Misconceptions
During any stage of life, exercise is essential for promoting optimal health and weight loss. However, many women operate under the misconception that exercise negatively impacts the taste or nutritional integrity of breastmilk. According to La Leche League, an extremely intense exercise session may slightly elevate levels of lactic acid in a mother's milk; however, this affects only the milk's taste---not its nutritional composition. Women should include a daily exercise regimen in any weight loss program. In addition to supporting a healthy weight, regular exercise can improve a mother's mental health, energy levels and cardiovascular fitness.
