Browse the evidence

Bariatric surgery (gastric bypass, sleeve gastrectomy, duodenal switch) is the most effective intervention for significant weight loss and metabolic benefits in severe obesity.

For severe obesity, bariatric surgery (like gastric bypass or sleeve gastrectomy) is the most effective way to achieve significant weight loss. It works by restricting stomach size and/or altering digestion. It also improves metabolic health. Recovery is faster with modern laparoscopic techniques.

Caloric restriction leads to a significant decrease in body weight in the short term.

Practitioners should consider caloric restriction as an effective short-term strategy for weight loss.

Lifestyle interventions (diet and exercise) remain the most cost-effective and durable strategy for weight loss and diabetes prevention, outperforming microbiome therapies in long-term weight management.

Diet and exercise are the most effective and affordable way to lose weight and prevent diabetes. They outperform probiotics and FMT for weight loss and provide durable benefits.

Adhering to national dietary guidelines using minimally processed foods (MPF) results in significantly greater weight loss and fat mass reduction compared to adhering to the same guidelines using ultraprocessed foods (UPF), primarily driven by lower energy intake.

If you want to lose weight, follow your country's official healthy eating guidelines. Doing so with minimally processed foods (like whole grains, fresh fruits, and vegetables) will help you lose more weight than doing so with ultraprocessed foods (like reformulated cereals and ready meals). However, even if you eat ultraprocessed foods, as long as they meet national nutritional standards (low sugar, salt, and fat, high fiber), you can still lose weight. The key is that minimally processed foods help you eat fewer calories naturally, likely because they are less energy-dense and take longer to eat.

Sustained weight loss of at least 5% is recommended for individuals with overweight or obesity at moderate atherosclerotic cardiovascular disease (ASCVD) risk to reduce cardiometabolic risk factors and delay type 2 diabetes onset.

If you are at moderate cardiovascular risk, aim to lose just 5% of your body weight through a daily calorie deficit of 500-750 calories and 150 minutes of weekly exercise. This modest loss is scientifically proven to significantly lower your blood pressure, improve cholesterol, and drastically reduce your risk of developing type 2 diabetes.

Bariatric surgery (Roux-en-Y or Sleeve Gastrectomy) provides superior long-term weight loss and metabolic remission compared to conservative lifestyle interventions alone.

If you have severe obesity and metabolic syndrome, lifestyle changes alone rarely sustain weight loss long-term. Bariatric surgery (like Sleeve or Gastric Bypass) is the most effective treatment, offering nearly 20% total body weight loss and high rates of diabetes/blood pressure remission that diet alone cannot achieve.

Treatment with tirzepatide resulted in a least-squares mean percent change in weight of -20.2% at week 72, compared to -13.7% with semaglutide.

Tirzepatide may be a more effective option for weight loss in obese adults without diabetes.

Tirzepatide led to a least-squares mean change in waist circumference of -18.4 cm, while semaglutide led to -13.0 cm.

Tirzepatide may also be beneficial for reducing waist circumference in obese adults without diabetes.

Participants in the tirzepatide group were more likely to achieve weight reductions of at least 10%, 15%, 20%, and 25% compared to the semaglutide group.

Tirzepatide may provide a higher chance of achieving significant weight loss milestones in obese adults without diabetes.

Retatrutide and dual agonists achieved equivalent mean weight loss of -11.0 kg, surpassing GLP-1RAs which had a mean weight loss of -9.0 kg.

Practitioners can expect retatrutide and dual agonists to provide significant weight loss compared to GLP-1RAs.

Retatrutide excels at achieving ≥ 15% weight loss with an odds ratio of 54.6.

Retatrutide may be particularly effective for patients aiming for significant weight loss.

All obesity management medications (OMMs) showed significantly greater total body weight loss percentage (TBWL%) versus placebo.

Practitioners can consider OMMs as effective options for weight loss in adult patients.

Cagrilintide-semaglutide resulted in a mean percent change in body weight of -20.4% from baseline to week 68 compared to -3.0% with placebo.

Cagrilintide-semaglutide may be an effective treatment option for significant weight loss in adults with overweight or obesity.

Participants receiving cagrilintide-semaglutide were more likely to achieve weight-loss targets of 5%, 20%, 25%, and 30% or more compared to placebo.

Cagrilintide-semaglutide may help patients achieve significant weight-loss goals.

All intermittent fasting and continuous energy restriction diet strategies reduced body weight when compared with ad-libitum diet.

Intermittent fasting and continuous energy restriction can be effective strategies for weight loss in diverse populations.

Alternate day fasting was the only form of intermittent fasting diet strategy to show benefit in body weight reduction compared with continuous energy restriction.

Alternate day fasting may be a more effective intermittent fasting strategy for weight loss compared to continuous energy restriction.

Oral semaglutide at a dose of 25 mg once daily resulted in a mean reduction in body weight of -13.6% from baseline to week 64.

Oral semaglutide may be an effective treatment option for weight loss in adults with obesity.

Participants in the oral semaglutide group were significantly more likely to achieve body-weight reductions of 5% or more, 10% or more, 15% or more, and 20% or more compared to the placebo group.

Oral semaglutide may help patients achieve significant weight loss milestones.

In Chinese adults with overweight or obesity, once-weekly mazdutide at a dose of 4 mg for 32 weeks led to a mean percentage change in body weight from baseline of -10.09%.

Mazdutide may be an effective treatment option for weight loss in adults with obesity or overweight.

In the 6-mg mazdutide group, the mean percentage change in body weight from baseline at week 32 was -12.55%.

Higher doses of mazdutide may lead to greater weight loss in adults with obesity or overweight.

73.9% of participants in the 4-mg mazdutide group achieved a weight reduction of at least 5% at week 32.

A significant proportion of adults with obesity or overweight may benefit from mazdutide treatment.

94.2% of patients achieved ≥ 5% weight loss after 6 months of tirzepatide treatment.

Practitioners can expect a high rate of significant weight loss among patients using tirzepatide.

The 5:2 total diet replacement (5:2TDR) resulted in a weight loss of -0.9 kg after 26 weeks, while the once-daily meal-replacement (DMR) group experienced a weight regain of 3.5 kg, leading to a between-group difference of -4.4 kg.

Practitioners may consider recommending 5:2TDR for better weight maintenance outcomes compared to DMR.

Both dietary interventions (5:2TDR and DMR) maintained weight losses greater than 15 kg below baseline at 26, 52, and 78 weeks.

Both interventions can be effective for long-term weight maintenance.