Bariatric surgery tops GLP-1 drugs and lifestyle changes in sustained weight loss efficacy
An extensive review of medical research from 2020 to 2024 has conclusively demonstrated that bariatric surgery, also referred to as metabolic or weight-loss surgery, yields the most substantial and longest-lasting weight loss results when compared to other interventions such as GLP-1 receptor agonists and lifestyle modifications. This significant finding was unveiled at the American Society for Metabolic and Bariatric Surgery (ASMBS) 2024 Annual Scientific Meeting.
According to the research, lifestyle modifications, encompassing diet and physical exercise, typically lead to an average weight reduction of 7.4%. However, the study notes that this weight is often regained within approximately 4.1 years. In contrast, more intensive interventions like GLP-1 receptor agonists and surgical procedures have shown greater efficacy. The studies analysed involved thousands of participants across various clinical and randomised trials.
The research highlighted the effectiveness of GLP-1 semaglutide, which, with five months of weekly injections, resulted in a 10.6% reduction in body weight. A more pronounced effect was observed with tirzepatide, where nine months of treatment led to a 21.1% weight loss. Nevertheless, approximately half of this weight was regained within a year after cessation of treatment with either drug. If treatment was sustained, patients receiving tirzepatide stabilised at a 22.5% weight loss after 17-18 months, while those on semaglutide reached a plateau at 14.9% during the same timeframe.
More profound outcomes were observed with metabolic and bariatric surgeries such as gastric bypass and sleeve gastrectomy. These procedures showed a total weight loss of 31.9% and 29.5% respectively, one year post-operation. Remarkably, a weight loss of around 25% was maintained for up to a decade following the surgery.
“Metabolic and bariatric surgery remains the most effective and durable treatment for severe obesity,” explained Marina Kurian MD, a co-author of the study and bariatric surgeon at NYU Langone Health. She further emphasised the underutilisation of such surgeries, advocating for their consideration earlier in the treatment process rather than as a last resort.
In 2022, approximately 280,000 metabolic and bariatric procedures were conducted in the U.S., representing just about 1% of the eligible population based on Body Mass Index (BMI) criteria. This is in the context of a prevailing obesity rate of 42.4% among Americans, as reported by the U.S. Centers for Disease Control and Prevention (CDC). Obesity is known to compromise the immune system, enhance chronic inflammation, and escalate the risk of numerous health issues including cardiovascular diseases, stroke, type 2 diabetes, and certain types of cancer.
Dr. Ann Rogers, ASMBS President-elect and Professor of Surgery at Penn State College of Medicine, who was not involved in the study, highlighted the importance of surgical interventions in combating obesity. “While new drug treatments show great promise and could lead to more successful outcomes, particularly with better affordability and insurance coverage, we are still not fully utilising the most effective tool we have—metabolic and bariatric surgery, which is safer and more effective than ever,” she stated.
The study comprised a systematic review of various research studies that explored weight loss through lifestyle changes, GLP-1s (Semaglutide or tirzepatide), or metabolic and bariatric surgery. The review of GLP-1s was based on four randomised clinical trials conducted between 2021 and 2024. Lifestyle interventions were examined across eight studies, while surgical approaches were evaluated through a review of 35 studies, including two randomised trials, covering approximately 20,000 patients in total.
