Ninety-nine studies in total:
13 RCTs on children and adolescents.
1 RCT and 2 non-randomised trials on preventive interventions.
13 RCTs on behavioural interventions.
12 RCTs on behavioural interventions with dietary component.
5 RCTs on behavioural interventions with dietary and exercise components.
2 RCTs on dietary interventions.
1 RCT on dietary and exercise interventions.
13 RCTs on pharmacological interventions.
15 RCTs on surgical interventions.
9 RCTs on maintenance.
11 RCTs on comprehensive interventions.
The methodological quality of many of the included studies was poor. Small sample sizes, high drop-out rates and a lack of intention-to-treat analysis made the interpretation of results difficult.
Family therapy programmes were effective in preventing the progression of obesity in already obese children.
Behavioural, diet and exercise programmes have all been shown to be effective in the treatment of adult obesity, particularly when two or more approaches are used in combination.
Pharmacological interventions appear to produce weight loss for up to 9 months, after which time a proportion of participants regain weight.
Surgery is normally considered only for morbidly obese patients. The weight loss associated with surgical interventions is greater and more sustained than that achieved by non-surgical methods. However, surgery is associated with complications that may affect the patient's quality of life.
Maintenance strategies have been shown to be effective at reducing the amount of weight regain following weight loss after treatment.