In conclusion, though the observational nature of the studies
included in the meta-analyses means that causal inference
cannot be proven, our findings contribute to a growing body of
evidence for a positive association between sugar-sweetened
soft drink intake and type 2 diabetes risk. We demonstrated this
to be attenuated by adjustment for BMI. There was a less consistent
trend for artificially sweetened soft drinks, and together with
the effect of adjusting for BMI, this may indicate an alternative
explanation for the observed association, such as lifestyle factors
or reverse causality. The temporal nature of the association
between soft drink intake and type 2 diabetes risk and whether
BMI modifies or mediates this association are crucial issues, and
future studies should attempt to address these and longitudinally
assess both BMI and intake trends. Recommendations to limit the
consumption of sugar-sweetened soft drinks by promoting the
supply of sugar-free alternatives depend, in part, on the nature
of the association with obesity and whether alternatives to arti-
ficially sweetened soft drinks also have negative consequences.