Twenty-three RCTs (n=14,569) were included in the review. Sample sizes ranged from 86 to 3,277 participants.
RCTs in non-diabetic participants (15 studies): All three weight loss drugs resulted in significant improvements in fasting glucose and fasting insulin in seven of 14 studies. Further results were reported.
RCTs in diabetic participants (eight studies): Glycated haemoglobin decreased by between 0.28% and 1.1% with orlistat (five studies) and by 0.3% to 0.6% with sibutramine and rimonabant (three studies). Differences were statistically significant between active drug and diet groups in all studies except one sibutramine study.