Nutrient interaction in relation to glycaemic response in isocarbohydrate and isocaloric meals.

ABSTRACT

The present study was designed to examine the effect of casein (Cs) on postprandial glycaemia when ingested with glucose (G) alone or in combination with corn oil (Co), cellulose (Cl) or pectin (P). The study was conducted on a pool of ten healthy male volunteers in two sets of five volunteers each. The meals administered in the two sets were similar in composition but were isocarbohydrate (100 g G) in one set, and isocaloric (400 kcal) in another set. The meals in each set consisted of G, G Cs, G Cs Co, G Cs Cl and G Cs P. Each of the five volunteers in a given set underwent five meal tolerance tests (MTT), once with each meal, in a Latin Square design. During the MTT, the meal was administered after an overnight fast. In addition to a fasting venous blood sample, blood was collected 0.5, 1.0, 1.5 and 2.0 h after ingestion for measurement of serum glucose and insulin levels. In both sets, the highest glycaemic response was that to G. In the isocarbohydrate set, G Cs gave a significantly lower glycaemic and insulinaemic response than G. Further addition of Co made no essential difference but both the fibre containing meals gave significantly lower glycaemic responses. The insulinaemic response was attenuated only in case of G Cs P but not in case of G Cs Cl. In the isocaloric set, Cs as G Cs was observed to stimulate insulin secretion rather than attenuate postprandial glycaemia G Cs Co gave a reduction in glycaemic as well as insulinaemic response as compared to G. Both fibre containing meals led to further reduction in both responses, P being somewhat more effective than Cl. Addition of other nutrients to G, in general, reduces postprandial glycaemia.