Low glycaemic-index foods

Accumulating data indicate that a diet characterized by low glycaemic-index (GI) foods not only improves certain metabolic ramifications of insulin re sistance, but also reduces insulin resistance per se. Epidemiological data also suggest a protective role against development of non-insulin-dependent diabetes mellitus and cardiovascular disease. A major disadvantage in this connection is the shortage of low-GI foods, and many common starchy staple foods, such as bread products, breakfast cereals and potato products, have a high GI. Studies in our laboratory show that it is possible to significa ntly lower the GI of starchy foods, for example by choice of raw material a nd/or by optimizing the processing conditions. Such low-GI foods may or may not influence glucose tolerance at a subsequent meal. Consequently, certai n low-GI breakfasts capable of maintaining a net increment in blood glucose and insulin at the time of the next meal significantly reduced post-prandi al glycaemia and insulinaemia following a standardized lunch meal, whereas others had no 'second-meal' impact. These results imply that certain low-GI foods may be more efficient in modulating metabolism in the long term. Alt hough the literature supports a linear correlation between the GI and insul inaemic index (II) of foods, this is not always the case. Consequently, mil k products elicited elevated IIs, indistinguishable from a white bread refe rence meal, despite GIs in the lower range. This inconsistent behaviour of milk products has not been acknowledged, and potential metabolic consequenc es remain to be elucidated.