Nutritional Interventions for Weight Loss in Lactating Women: A Comprehensive Systematic Review of Clinical Trials.

BACKGROUND: Effective postpartum weight management is essential for maternal health, yet the impact of specific nutritional strategies during lactation remains poorly defined. OBJECTIVES: This systematic review evaluated the impact of nutritional interventions on weight management among lactating women. METHODS: A systematic search was conducted in PubMed, Web of Science, Scopus, and Bireme/LILACS (December 2022; updated March 2026). We included clinical trials assessing nutritional interventions for weight management during the lactation period. Study quality was evaluated using the Risk of Bias Tool 2 and the Risk of Bias in Non-Randomized Studies of Interventions. RESULTS: Seven clinical trials met the inclusion criteria, initiated during pregnancy (n = 1) or lactation (n = 6), with intervention durations ranging from 11 days to 12 months. Caloric restriction (deficit of 500 kcal/day) combined with macronutrient adjustment was associated with significant postpartum weight loss and improved body composition. Conversely, micronutrient supplementation alone demonstrated no effect on weight reduction. The evidence is constrained by a limited number of studies, heterogeneous intervention protocols, varying postpartum stages, and incomplete reporting, which restricts the generalizability of the findings. CONCLUSIONS: While evidence remains limited, caloric restriction for durations exceeding 1 month appears to promote weight loss in lactating women without self-reported adverse effects on breastfeeding performance. However, caution is important regarding the use of caloric restriction during lactation, due to the knowledge gap concerning its impacts on the mother-infant dyad and breast milk composition.