ABSTRACT Objective This study assessed changes in body composition and 24‐h energy metabolism at 6 and 12 months after initiation of a 1‐month very low‐calorie ketogenic diet (VLCKD) in women with obesity. Methods Seventeen women with obesity who completed a 1‐month VLCKD underwent a 4‐week transition phase with carbohydrate reintroduction, followed by a hypocaloric balanced diet. Assessments of body composition by dual‐energy X‐ray absorptiometry (DXA) and 24‐h energy expenditure (24hEE) by a whole‐room indirect calorimeter were performed. Results Following the initial 7% weight loss, body weight further decreased at 6 months (−3.9%, p < 0.05), primarily driven by a significant decrease in fat mass (−10%, p < 0.05). From 6 to 12 months, three participants continued to lose weight, whereas most remained stable or partially regained. Lean soft tissue, decreased during the VLCKD phase, remained stable throughout follow‐up. Both 24hEE and 24‐h sleeping metabolic rate exhibited a progressive trend toward increase. Minute‐by‐minute 24hEE trajectories revealed a significant increase in metabolic rate from 1 to 6 months ( p < 0.001). The metabolic adaptation observed after 1 month of VLCKD was no longer detectable at either 6 or 12 months. Conclusions These findings provide novel insight into the physiological adaptations following VLCKD, supporting its role in supervised weight loss programs for selected patients. Trial Registration ClinicalTrials.gov identifier: NCT07418281
Basolo et al. (Mon,) studied this question.