Evaluation of the effectiveness of a restricted diet therapy package combining standardised caloric intake with exercise in obese patients: A 12-month randomised controlled trial.

Objectives to background and aims: Obesity is a major global health challenge associated with increased risks of diabetes and cardiovascular disease. Although calorie restriction and exercise are cornerstone strategies for weight management, long-term adherence remains difficult in real-world settings. This randomised controlled trial aimed to evaluate the effectiveness of a structured calorie-restricted dietary therapy package combined with exercise in achieving weight loss and improving metabolic and psychological outcomes among obese adults. 

Methods: In this 12-month, parallel-group randomised controlled trial, 99 obese adults were randomly assigned to an intervention group (standardised meal kit + exercise) or a control group (standard dietary advice + exercise). Weight, glucose, lipid profiles, and mental health outcomes were assessed at baseline, 3, 6, and 12 months. LASSO regression was used to identify predictors of successful weight loss, and linear mixed-effects models evaluated associations between percentage weight loss and changes in glycaemic, lipid, and psychosocial outcomes. 

Results: By month 12, all participants in the intervention group achieved ≥5 % weight loss, with 59.18 % achieving ≥10 %, compared to 38.00 % and 6.00 % in the control group, respectively. Group assignment was the strongest predictor of weight loss success, followed by HDL levels and family history of obesity. Each 1 % reduction in body weight was significantly associated with lower FPG, 2hPG, TC, TG, and LDL-C, as well as improved SDS, SAS, and SF-36 scores. These associations remained significant after adjusting for confounders. However, interaction analyses showed no significant between-group differences in the effect of weight loss on outcomes. 

Conclusion: A standardised dietary therapy package combining calorie restriction and exercise is a feasible and effective strategy to achieve clinically meaningful weight loss and improve metabolic and psychological health in obese adults. Although both groups experienced improvements, the structured intervention enhanced adherence and overall effectiveness.