Effect of Distinct Lifestyle Interventions on Mobilization of Fat Storage Pools: CENTRAL Magnetic Resonance Imaging Randomized Controlled Trial.

Background: We aimed to assess whether distinct lifestyle strategies can differentially affect specific body adipose depots. Methods: We performed an 18-month randomized controlled trial among 278 sedentary adults with abdominal obesity (75%) or dyslipidemia in an isolated workplace with a monitored provided lunch. Participants were randomized to isocaloric low-fat or Mediterranean/low-carbohydrate (MED/LC) diet+28 g walnuts/day with/without added moderate physical activity (PA; 80% aerobic; supervised/free gym membership). Overall primary outcome was body fat redistribution, and the main specific end point was visceral adipose tissue (VAT). We further followed the dynamics of different fat depots (deep and superficial subcutaneous, liver, pericardial, muscle, pancreas, and renal sinus) by magnetic resonance imaging. Results: Of 278 participants (age, 48 years, 89% men, body mass index, 30.8 kg/m 2 ), 86% completed the trial with good adherence. The low-fat group preferentially decreased reported fat intake (−21.0% versus −11.5% for the MED/LC; P P + groups significantly increased the metabolic equivalents per week versus the PA − groups (19.0 versus 2.1; P =0.009). Whereas final moderate weight loss was indifferent, exercise attenuated the waist circumference rebound with the greatest effect in the MED/LC PA+ group ( P + with either diet had a significantly greater effect on decreasing VAT (mean of difference, −6.67cm 2 ; 95% confidence interval, −14.8 to −0.45) compared with PA − . The MED/LC diet was superior to the low-fat diet in decreasing intrahepatic, intrapericardial, and pancreatic fats ( P Conclusions: Moderate weight loss alone inadequately reflects the significant lifestyle effects on atherogenic and diabetogenic fat depots. The MED/LC diet mobilizes specific ectopic fat depots, and exercise has an independent contribution to VAT loss. Fat depots exhibit diverse responsiveness and are differentially related to cardiometabolic markers. Distinct lifestyle protocols may uniquely induce fat mobilization from specific anatomic sites. Clinical Trial Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01530724.