Weight Gain and Body Composition Changes During and After Breast Cancer Treatment: A Systematic Review

Abstract

Background: Weight gain and adverse changes in body composition are common among women undergoing treatment for breast cancer. These changes may negatively affect metabolic health, quality of life, treatment outcomes, and long-term survivorship.

Objective: To systematically synthesize current evidence on weight gain, adiposity, body composition, and related metabolic alterations during and after breast cancer treatment in adult women.

Methods: A systematic review was conducted to identify studies evaluating changes in body weight, body mass index, adiposity, body composition, or metabolic markers during or after breast cancer treatment. Primary observational and interventional studies were included in the qualitative synthesis, while review articles and commentaries were used to provide contextual background. Owing to heterogeneity in study design, patient populations, treatment modalities, and outcome measures, findings were synthesized narratively.

Results: Seven primary studies met the eligibility criteria for qualitative synthesis. Overall, the evidence indicates that clinically meaningful weight gain and unfavorable body composition changes occur in a substantial proportion of women receiving treatment for breast cancer, particularly during chemotherapy and the early survivorship period. Common findings included short-term weight gain during the first year after diagnosis or treatment, persistence of excess weight over longer follow-up, increased fat mass and adiposity, and deterioration in cardiometabolic risk factors. Baseline body mass index, chemotherapy, endocrine therapy, dietary patterns, physical activity, and neighborhood food environment were identified as important factors influencing these outcomes.

Conclusions: Current evidence supports routine monitoring of body weight and body composition throughout breast cancer treatment and survivorship. Early preventive interventions emphasizing healthy dietary patterns, regular physical activity, and identification of patients at increased metabolic risk may help mitigate treatment-related weight gain and improve long-term health outcomes. Further high-quality prospective studies are needed to clarify underlying mechanisms and evaluate effective intervention strategies.