In a July 2012 review, Tappy and Mittendorfer looked at whether the current science behind fructose supports implementation of new public health policies for which fructose critics have been clamoring. They concluded that, “There is clearly a need for more clinically relevant research before taking drastic public health actions to specifically target fructose-containing caloric sweeteners…because there is little evidence that fructose itself causes significant metabolic alterations when consumed in amounts consistent with current dietary habits.”
The authors noted that some observational studies have reported an association between sugar intake and body weight. These associations, however, became insignificant once total energy intake was accounted for. Such findings suggest that overall energy intake, and not sugar intake, is responsible for weight gain. In further support of this, the authors highlighted a meta-analysis of 41 short term intervention studies that found that fructose led to increased body weight when it was a part of an excessive energy diet but not when it was a part of a balanced energy diet.
In observational studies reporting associations between sugar intake and non-communicable diseases (i.e. diabetes or nonalcoholic fatty liver disease), the authors noted that associations were typically dependent on body weight. They also noted that many clinical studies using relevant amounts of fructose, reported no adverse effects of fructose on blood pressure or insulin levels in study participants.