Comparing Intensive Weight Loss Program and Bariatric Surgery for Adults Aged 18 to 60 With Severe and Complex Obesity

What this Trial Is About

The trial investigates the benefits and risks of an intensive weight loss intervention compared with bariatric surgery for adults with severe and complex obesity. The goal is to understand how these approaches compare and to guide future treatment options for people who currently have bariatric surgery as the only effective choice. This research is led by the Lighthouse Consortium on Obesity Management LightCOM and aims to inform care pathways for obesity treatment. The intensive weight loss intervention lasts two years and includes three phases an induction phase with total dietary replacements and behavioral support plus weight loss medication if needed a weight loss continuation phase with gradual reintroduction of healthy foods, physical activity, behavioral support, and medication as required and a maintenance phase with continued healthy diet, activity, and medication as needed, with return to induction if weight regain occurs. The comparator group receives bariatric surgery, either Roux-en-Y gastric bypass or sleeve gastrectomy. Participants will undergo assessments over 104 weeks including measures of metabolic syndrome MetS-Z, body weight, gait speed, and mental health scores. The study includes regular monitoring of diet, medication use, physical activity, and adherence. Safety and long-term outcomes are followed throughout the two-year study period to evaluate the effects of each intervention on obesity and related health aspects.

Intensive Weight Loss Intervention Versus Bariatric Surgery for Adults With Severe and Complex Obesity: the LightBAR Randomised Trial