How effective and safe are screening methods and treatments for obesity?

Systematic review with narrative synthesis.

The review found no RCTs that studied the efficacy of obesity screening. Recent RCTs found that high intensity counselling or behavioural interventions and pharmacological interventions could result in moderate weight loss (see Table 1). The RCTs found that side effects were common (11 to 79%) with pharmacological treatment but not usually serious. Three RCTs found no significant differences in weight loss among different methods of gastric banding surgery (open vs. laparoscopic) or different placements of the gastric band (oesophogastric vs. retrogastric; gastric vs. oesophogastric). All gastric banding groups experienced considerable weight loss (from 17kg to over 40kg at 1–2 years follow-up). The RCTs did not report on mortality, but one large cohort study of different surgical techniques reported post-operative mortality of 0.2%.

Table 1 Summary of outcomes of recent RCTs  Intervention  Number RCTs  RCTs finding significant (P⩽0.05) benefit with intervention  Mean weight loss difference versus control (kg)†  Follow up (months)  Counselling/behavioural  High intensity  6  4  Up to −5.5  12 to 54  Moderate intensity  2  1  −0.25 to −3.5  12 to 18  Low intensity  3  1  NR  12 to 36  Pharmacological  Sibutramine  6  5  −2.8 to −7.8  6 to 12  Orlistat  7  6  +0.5 to −4.5  6 to 12.5  Metformin  2  1  Up to −2.0  6 to 33.6  Placebo/no treatment/usual care controlled RCTs not included in previous systematic reviews.  †Where reported; NR=not reported

Counselling or behavioural interventions and pharmacotherapy can result in moderate weight loss (approximately 3 to 5kg) over at least 6–12 months. Pharmacotherapy does have adverse effects. Surgery results in considerable weight loss in very obese people, but there is a risk of mortality.