Abstract

To examine the level of oxidation between different carbohydrate foodstuffs ingested one hour before exercise, three experiments were conducted in men. They performed a series of exercise tests of two hours duration at 60 VO2max preceded in experiment I by ingestion of one of five isocaloric (836 kJ) successive meals of bread, potatoes, rice, spaghetti, or glucose; in experiment II, by either spaghetti or glucose, both naturally 13-C enriched; in experiment III, by one of four 13-C labelled meals containing starches differing in their proportion of amylose and amylopectin and in their culinary preparation. Results show: 1) The following glucose and insulin response from the highest to the lowest was: glucose>potatoes>bread>rice>spaghetti and after 30 min of exercise a significantly lower blood glucose concentration observed after glucose and potato diets compared to the rice and spaghetti meals. The level of 13-CO2 production from the food ingested in experiments II and III was expressed in terms of Atom Percent Excess (APE). Data suggests that spaghetti is oxidized to a lesser degree than glucose. The comparison between starches shows that gelatinized amylopectin is metabolized to the same extent as glucose when there is a progressive decline in the level of oxidation from gelantinized amylose and crude amylopectin to crude amylose. Verf.-Referat