Table 3. Summary of certainty of evidence for each outcome. Outcome No. of studies Participants (n) Effect estimate Heterogeneity (I2) Certainty of evidence Reasons for downgrading BMI 13 310 MD = -2.58 kg/m2, 95% CI: -3.35 to -1.81 10% Moderate Risk of bias BFP 13 305 MD = -2.95%, 95% CI: -4.45 to -1.46 10% Moderate Risk of bias WC 5 132 MD = -8.15 cm, 95% CI: -11.60 to -4.71 17% Moderate Risk of bias LBM 10 210 MD = -3.00 kg, 95% CI: -5.87 to -0.14 74% Low Risk of bias; inconsistency; potential publication bias TG 5 146 SMD = -0.57, 95% CI: -0.93 to -0.20 30% Low Risk of bias; imprecision SBP 6 162 MD = -6.62 mmHg, 95% CI: -10.16 to -3.09 55% Low Risk of bias; inconsistency DBP 7 178 MD = -2.60 mmHg, 95% CI: -4.56 to -0.65 0% Moderate Risk of bias TC 6 172 SMD = -0.31, 95% CI: -0.62 to 0.00 29% Low Risk of bias; imprecision LDL-C 6 168 SMD = -0.28, 95% CI: -0.59 to 0.03 20% Low Risk of bias; imprecision HDL-C 7 181 SMD = 0.30, 95% CI: 0.00 to 0.60 44% Low Risk of bias; imprecision High = very confident that the true effect lies close to that of the estimate; Moderate = moderate confidence in the effect estimate; Low = limited confidence in the effect estimate; Very low = very little confidence in the effect estimate.