The Impact of Different Nutritional Approaches on Body Composition in People Living with Obesity.

Objective: This narrative review aimed to provide an overview of the current evidence on the impact of various nutritional strategies on body composition in people living with obesity (PLwO), with particular attention to fat mass (FM), fat-free mass (FFM), and fat distribution.

Results: Obesity is increasingly linked to cardiometabolic complications, yet common diagnostic metrics such as body mass index (BMI) do not capture changes in FM or FFM. Recent studies highlight the variable effects of different dietary interventions on body compartments. High-protein and ketogenic diets are associated with greater preservation of FFM and reductions in visceral adipose tissue (VAT), while the Mediterranean diet shows promise for long-term adherence and improvements in metabolic health. Intermittent fasting and time-restricted eating demonstrate efficacy in FM reduction but present mixed results regarding FFM retention and sustainability. Dietary strategies exert diverse effects on body composition in PLwO, underscoring the importance of tailoring interventions to individual metabolic profiles and health goals. Personalized nutrition approaches that prioritize the preservation of lean mass and reduction of VAT, along with sustainable adherence, are critical for optimizing obesity management beyond weight loss alone.