Recent research in Northern Ireland suggests that high sugar intake does not directly affect insulin resistance and subsequent diabetes risk. Researchers from Belfast's Royal Victoria Hospital and Queen's University report in the American Diabetes Association's journal Diabetes that no significant difference in the measures of insulin resistance was observed in their study.

Such findings are based on a small randomised, controlled, cross-over trial of 13 healthy men receiving either a high-sugar diet (providing 25 per cent of their energy) or a diet providing 10 per cent of their energy as sugar for 6 weeks (about average for a British adult).

While sugar has traditionally been linked to the development of diabetes, these findings challenge that thinking, and show that intakes more than double what is currently recommended do not appear to have an adverse effect on markers of diabetes risk. Of course it was a small and very short-term study.

The researchers set out to test guidelines for the healthy population that advise a restriction in sucrose intake, and assigned the men (average age 33, average BMI 26.6 kg per sq.m) to sequential 6-week dietary interventions separated by 4-weeks.

The equal calorie diets were prepared to have approximately the same carbohydrate, fat and protein content, with the only difference being that sucrose was used in place of starch. The high sucrose diet contained, on average, 200g per day while the low sucrose diet contained 80g of sucrose.

The researchers report that no weight changes were recorded for either group, and there was no significant differences in glucose uptake and production. Interestingly, no significant adverse effects for a number of other metabolic and physiologic parameters were observed between the groups, including elasticity of the arteries, and glycaemic profiles.

This study basically showed that a high-sucrose intake as part of an eucaloric, weight-maintaining diet had no detrimental effect on insulin sensitivity, glycaemic profiles, or measures of vascular compliance in healthy non-diabetic subjects. This may point to other dietary factors such as excess calories and lifestyle factors such as physical inactivity and weight gain as being more important than carbohydrate type in the development of diabetes.

Source: Diabetes
Volume 55, Pages 3566-3572, doi: 10.2337/db06-0220
"Effect of eucaloric high- and low- sucrose diets with identical macronutrient profile on insulin resistance and vascular risk; A randomised controlled trial"
Authors: R.N. Black, M. Spence, R.O. McMahon, G.J. Cuskelly, C.N. Ennis, D.R. McCance, I.S. Young, P.M. Bell, S.J. Hunter