Study of weight loss intervention to find an effective strategy for obesity management and the TARGET of weight loss amount for reducing health disorders (SLIM-TARGET): a randomized controlled trial.

This randomized controlled study aimed to clarify weight loss targets for improving obesity-related disorders in individuals with overweight or obesity. A total of 294 participants with six obesity-related conditions were assigned to either a standard or intensive treatment group, with 12-month weight loss targets of ≥3% and ≥7%, respectively. The standard group followed the Japanese Guidelines for the Management of Obesity Disease 2016. The intensive group received frequent nutritional guidance, enhanced diet and exercise therapy, and additional pharmacotherapy. The primary outcome was weight loss and improvement in at least two obesity-related disorders at 12 months. Secondary outcomes included remission of health disorders, improvement in at least one health disorder, and visceral fat reduction. At 12 months, the weight loss was -2.5% in the intensive group and -1.7% in the standard group, with no significant difference in the primary outcome. However, remission of health disorders was achieved in 16.9% of the intensive group compared with 6.2% of the standard group (adjusted odds ratio 3.079; 95% CI 1.075-8.823; p = 0.036). Visceral fat reduction was greater in the intensive group (-20.46 cm2 vs. -8.9 cm2; p = 0.039). Intensive treatment significantly improved blood pressure early and increased treatment motivation scores by 10.9% (95% CI: 1.2-20.6) at 24 months (p = 0.004). In both groups, ≥60% of the participants showed improvement in at least one disorder. Despite not achieving the target weight loss, resulting in no significant difference in the primary outcome, the intensive treatment increased remission percentages, improved early blood pressure control, and enhanced long-term treatment motivation. The study was registered at UMIN Clinical Trials Registry (UMIN ID: UMIN000031862).