Research

Mixed

Behavioral interventions (diet, exercise, or lifestyle) and pharmacologic interventions (orlistat or metformin) combined with behavioral strategies both result in clinically significant weight loss and reduced incidence of type 2 diabetes in overweight and obese adults.

For adults with overweight or obesity, combining dietary changes with increased physical activity is effective for weight loss. Adding orlistat or metformin to this behavioral plan can enhance weight loss and reduce the risk of type 2 diabetes, particularly in those with prediabetes. While exercise alone may not be sufficient for significant weight loss, combining it with diet is beneficial. Be aware that orlistat can cause mild gastrointestinal side effects, which often subside.

ModerateSupportsMEDIUM confidence
There is moderate quality evidence that behavioural and pharmacologic plus behavioural treatments for overweight and obesity in adults lead to clinically important reductions in weight and incidence of type 2 diabetes in prediabetic populations.
Leslea Peirson et al. · CMAJ Open · 2014

Why this rating

Moderate quality evidence per GRADE framework, downgraded for risk of bias and heterogeneity.

Source

Treatment for overweight and obesity in adult populations: a systematic review and meta-analysis

Leslea Peirson et al. · CMAJ Open · 2014

DOI 10.9778/cmajo.20140012

Meta-analysis · 68 studiesCited 90×
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

This is one finding among thousands. Every one is graded and traced to its source, so you can see what the evidence actually supports. Browse the research →