| Outcome; intervention focus | Effect on % weight loss | Statistical heterogeneity (within group) p value (I2 value, %) | Test for between-group differences p value (I2 value, %) | No. of participants | No. of studies | Quality of evidence rating | ||||
|---|---|---|---|---|---|---|---|---|---|---|
| RR (95% CI) | Absolute risk reduction, % | No. needed to treat (95% CI) | ||||||||
| Loss of ≥ 5% baseline body weight | ||||||||||
| Overall | 1.77 (1.58–1.99) | 20.42 | 5 | (4–7) | < 0.00001 | (69) | NA | 9 857 | 24 | Low |
| Behavioural | 1.75 (1.35–2.27) | 11.67 | 9 | (5–18) | 0.01 | (57) | 0.88 (0) | 2 841 | 11 | Low |
| Pharmacologic + behavioural | 1.79 (1.57–2.04) | 24.26 | 4 | (3–6) | < 0.00001 | (76) | 7 016 | 13 | Low | |
| Loss of ≥ 10% baseline body weight | ||||||||||
| Overall | 1.91 (1.69–2.16) | 11.24 | 9 | (7–12) | 0.27 | (16) | NA | 7 523 | 16 | Low |
| Behavioural | 2.04 (1.30–3.21) | 8.01 | 12 | (6–44) | 0.81 | (0) | 0.81 (0) | 744 | 3 | Moderate |
| Pharmacologic + behavioural | 1.92 (1.67–2.21) | 11.81 | 8 | (6–12) | 0.14 | (31) | 6 779 | 13 | Low | |
| Incidence of type 2 diabetes | ||||||||||
| Overall | 0.62 (0.50–0.77) | 5.75 | 17 | (13–29) | 0.02 | (54) | NA | 8 624 | 9 | Moderate |
| Behavioural | 0.55 (0.42–0.72) | 8.88 | 11 | (9–18) | 0.25 | (23) | 0.11 (60) | 3 198 | 7 | Moderate |
| Pharmacologic + behavioural | 0.72 (0.59–0.87) | 3.60 | 28 | (19–60) | 0.26 | (27) | 5 426 | 3 | Moderate | |
Note: CI = confidence interval, NA = not applicable, RR = risk ratio.