Acute fuel selection in response to high-sucrose and high-starch meals in healthy men

Abstract

Background: Despite considerable controversy over the inclusion of sucrose in the diets of people with diabetes, the acute metabolism of sucrose is not completely understood. Objective: Our objective was to investigate the metabolism of the monomeric constituents of sucrose after a high-sucrose meal. Design: Three test meals were consumed in a randomized, crossover design by 7 healthy male volunteers. Two of the meals were high in sucrose; one was supplemented with 200 mg uniformly labeled [13C]fructose and one was supplemented with 200 mg [13C]glucose. The other meal was high in starch, supplemented with 200 mg [13C]glucose. Fifty percent of energy was supplied as sucrose in the high-sucrose meals and as starch in the high- starch meal. Breath 13CO2 enrichment was measured at 15-min intervals and indirect calorimetry was performed for five 20-min sessions immediately before and during a 6-h postprandial period. Results: Carbohydrate oxidation rates rose much faster after the high-sucrose meals than after the high- starch meal. Breath 13CO2 enrichment rose faster and peaked earlier and at a higher value when [13C]fructose rather than [13C]glucose was given with the high-sucrose test meal. Values for breath 13C2 enrichment from [13C]glucose after the high-starch meal were intermediate. Conclusions: These results show that fructose is preferentially oxidized compared with glucose after a high-sucrose meal and that glucose is oxidized more slowly after a high-sucrose meal than after a high-starch meal.