Background

Obesity is a chronic disease requiring long-term treatment to achieve sustainable weight loss. Based on published data, three treatment approaches were compared regarding their effectiveness and stability of results: lifestyle interventions, GLP-1 receptor agonists (semaglutide and tirzepatide), and bariatric surgery (Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy).A systematic review of lifestyle interventions demonstrated a 7.4% mean weight loss at the end of the treatment period, but 0.14% of weight was regained per month post-treatment, reaching pre-intervention weights within 4.1 years.Weekly injections of semaglutide for 20 weeks and tirzepatide for 36 weeks resulted in 10.6% and 21.1% weight loss, respectively. Once injections were stopped, approximately half of that weight was regained within a year. If injections were continued, a plateau was reached after 17-18 months at 22.5% for tirzepatide and 14.9% for semaglutide. Within 2 years of semaglutide treatment, approximately 2% of the lost weight was regained.A systematic review of weight loss outcomes after RYGB and sleeve gastrectomy demonstrated a total weight loss of 31.9% and 29.5% one year after surgery, respectively. Over the following years, roughly 5-7% that weight was regained, so that both procedures resulted in a stable total weight loss of approximately 25% after 8-10 years.Lifestyle interventions do not lead to sustainable weight loss, and the effect of weight loss medication were also not permanent if the medication was not continued. In comparison, bariatric surgery showed the largest effect and resulted in sustainable weight loss in the years after treatment.