Il ruolo della sensibilità all'insulina nelle variazioni della massa magra durante la perdita di peso con o senza esercizio fisico

This study aimed to investigate the association between baseline insulin sensitivity (S I ) and changes in total lean mass (LM) and appendicular LM (ALM) during a diet‐induced weight loss program with or without exercise. We conducted a secondary data analysis from a controlled weight loss study in premenopausal women with overweight aged 21–41. Women were randomized into three groups: diet‐only, diet plus aerobic exercise, or diet plus resistance exercise. Body composition was assessed using dual‐absorptiometry X‐ray and S I using an intravenous glucose tolerance test. Multiple linear regression was used to determine if baseline S I was predictive of changes in total LM and ALM. There were significant group‐S I interactions on changes in total LM ( β = 0.474, p = 0.003, adjusted r 2 = 0.371) and ALM ( β = 0 0.462, p = 0.009, adjusted r 2 = 0.231) after adjusting for covariates, indicating that greater baseline S I was associated with less LM loss only in women who did not exercise. Higher baseline S I is associated with greater retention of LM when weight loss is induced with diet alone, but not when exercise (aerobic or resistance) is included. This reinforces the importance of including exercise in all weight loss interventions. Trial Registration: ClinicalTrials.gov identifier: NCT00067873