Ten RCTs were included in the review (n=3,677). Sample sizes ranged from 30 to 1,162 participants. Two studies were rated as being of good quality and eight were rated as fair (according to the CONSORT criteria). Attrition rates ranged from 9% to 67%.
None of the four studies of primary care provider counselling alone resulted in clinically significant weight loss (losses in active arms ranged from 0.1kg to 2.3kg). Two of three studies of lifestyle counselling with pharmacotherapy produced clinically significant weight loss (losses in the active arms in the three studies ranged from 1.7kg to 7.5kg). Weight losses in active treatment arms in studies of collaborative interventions ranged from 0.4kg to 7.7kg.