The objective was to conduct two systematic reviews and meta-analysis of controlled feeding trials to investigate the effect of fructose on measures of glycemic control and insulin sensitivity, in humans. The glycemic control analysis of 58 trials (n=1021) showed a clinically significant reduction in HbA1c when fructose was isoenergetically substituted for other carbohydrates, without adverse effects on fasting glucose or insulin. When fructose supplemented the background diet, providing excess energy, fasting glucose was elevated. Similarly, the insulin sensitivity (IS) analysis (45 trials, n=791) found a tendency for improvement in whole-body IS with fructose substitution, with no change in hepatic IS or HOMA-IR. Fructose supplementation, however, impaired hepatic IS with a trend for impairment in whole body IS and HOMA-IR. Overall, the results suggest that replacement of moderate doses of carbohydrate with fructose may have a beneficial effect on glycaemia and IS, although this effect may be negated with excess calories.M.Sc
