Individual Variability in Energy Compensation After a 12-Week Supervised Exercise Intervention

This prospective, single-arm interventional study will investigate why adults receiving the same prescribed dose and relative intensity of exercise show divergent changes in energy balance, body weight, and body composition. A total of 150 sedentary Chinese adults aged 18-40 years with overweight or obesity will complete a 12-week, supervised treadmill exercise programme. Exercise will be performed five times per week at an intensity corresponding to 60% of each participant\'s measured maximal oxygen uptake. Prescribed exercise energy expenditure will increase progressively from 150 kcal per session in Weeks 1-4 to 250 kcal per session in Weeks 5-8 and 350 kcal per session in Weeks 9-12. The primary objective is to quantify inter-individual variability in energy compensation after the standardized intervention. Detailed measurements will characterize total and resting energy expenditure, energy intake, appetite, physical activity, body composition, glucose dynamics, cardiorespiratory fitness, brain responses to food-related stimuli, and molecular phenotypes. Multi-omics analyses will include gut microbiome, metabolomic, proteomic, extracellular-vesicle, peripheral blood mononuclear cell, and transcriptomic assessments. The study will explore physiological, behavioral, and molecular factors associated with divergent compensatory responses. No randomized comparator group is included; therefore, causal comparisons between exercise and non-exercise conditions are outside the study scope.