Planetary Health Diet Adherence Improves Weight and Body Composition During Energy Restriction

OBJECTIVE: Obesity management relies on energy restriction, yet the contribution of dietary quality to weight-loss and body composition outcomes during hypocaloric interventions remains poorly characterized. This study evaluated whether adherence to the Planetary Health Diet (PHD), as a measure of diet quality, and its key components is associated with weight loss and body composition during energy restriction. METHODS: Data from 403 adults with overweight or obesity were analyzed at baseline and at 3, and 6 months across two controlled dietary interventions prescribing a 30% energy deficit. PHD adherence was quantified using an energy-adjusted score based on EAT-Lancet dietary targets. Excellent weight loss was defined as ≥ 10% body weight reduction. Associations were assessed using mixed models, logistic regression, and mediation analyses. RESULTS: ; 95% CI: -1.62 to -0.31; p = 0.005). Each 10-point increase in adherence increased odds of achieving ≥ 10% weight loss by 49% (OR = 1.49; 95% CI: 1.03-2.16). Red and processed meat reduction and higher whole-grain intake mediated associations. CONCLUSIONS: Greater PHD adherence during energy restriction was associated with greater weight loss and improved body composition. TRAIL REGISTRATION: ClinicalTrials.gov identifiers NCT02737267 and NCT03183193.