Effects of conventional sucrose-based, fructose-based and isomalt-based chocolates on postprandial metabolism in non-insulin-dependent diabetics.

Milk chocolate is rich in both sucrose and fat, and is therefore considered unsuitable for diabetics. Nevertheless there is little information on the metabolic effects of conventional chocolate or specialized formulations with reduced sucrose content. In the present study six male non-insulin-dependent diabetes mellitus patients (age range 35-60 years; body-mass index less than 28) consumed test meals of chocolate (75 g) on three separate occasions. The control chocolate contained sucrose (45.5% w/w); the test chocolates contained either fructose (45.5% w/w) or isomalt (45.1% w/w). The latter is a sweet disaccharide alcohol which has no glycaemic effect when consumed as a pure compound. Venous blood samples were obtained at 30 min intervals for 5 h, and analysed for glucose, insulin, lactate and triglycerides. All three chocolates provoked a sustained rise in blood glucose, which reached a maximum at 90 min after ingestion and returned to baseline values by 5 h. The highest blood glucose levels occurred after conventional chocolate, and differences were statistically significant at 60 and 90 min (P less than 0.05). The area under the glycaemic curve for isomalt chocolate was 36% smaller than that for conventional chocolate (P less than 0.05), and there were differences in insulin and lactate levels, consistent with the lower glycaemic effect. The glycaemic response to the fructose-based chocolate was also lower than that to control chocolate but the difference was not significant. All three chocolates led to a similar sustained rise in serum triglyceride levels. Isomalt appears to be a palatable alternative sweetener capable of reducing the glycaemic effect of diabetic confectionary.