Table 3.

GRADE assessment for the effect of lifestyle changes on T2D risk.

Outcome	No. of Studies	Study Design	Certainty Assessment					RR [95% CI]	Certainty
			Risk of Bias	Inconsistency	Indirectness	Imprecision	Other Considerations
T2D risk reduction	Seven	randomized trials	not serious	not serious a	not serious	not serious	none	0.53 [0.41, 0.67]	⨁⨁⨁⨁ HIGH

CI = confidence interval; GRADE = grading of recommendations assessment, development, and evaluation; RR = risk ratio; T2D = type 2 diabetes. ^a Although there was significant heterogeneity (I² = 65%, p = 0.01), the removal of one study [34] explained some of the heterogeneity, which changed it from significant to non-significant (I² = 36%, p = 0.16). However, the estimate of effect did not change appreciably. Furthermore, this inconsistency was not considered serious as the magnitude of effect remained large and in the same direction across all the studies (RR < 0.72).