Ghrelin response to carbohydrate-enriched breakfast is related to insulin.

BACKGROUND

Ghrelin plays an important role in the regulation of food intake. Little is known about how ghrelin concentrations are modified by dietary factors.

OBJECTIVE

We examined the effects of both amount and type of carbohydrate on ghrelin concentrations and all correlations among the variables ghrelin, glucose, insulin, leptin, and all 4 subjective measures of appetite.

DESIGN

Twenty healthy nonobese men were studied in a double-blind, randomized, crossover design. Subjective measures of appetite and concentrations of ghrelin, glucose, insulin, and leptin were frequently assessed for 4 h after liquid breakfast meals differing in energy content and carbohydrate structure-ie, water, low-calorie (LC) meal, high-calorie simple carbohydrate (HC-SC) meal, and high-calorie complex carbohydrate (HC-CC) meal.

RESULTS

Ghrelin concentrations decreased after the HC-SC breakfast by 41%, after the HC-CC breakfast by 33%, and after the LC breakfast by 24%. No significant differences in ghrelin concentration among the 3 breakfasts were observed until 120 min. Ghrelin concentrations were correlated with subjective measures of hunger (r=0.51) and fullness (r=-0.44). The percentage decrease in ghrelin between 0 and 30 min was inversely correlated with the percentage increases in insulin (r=-0.76) and glucose (r=-0.79) but not with changes in leptin (r=0.10). The percentage changes in ghrelin concentrations between 30 and 180 min were correlated with the percentage changes in insulin (r=-0.53) and leptin (r=-0.47) but not with changes in glucose (r=0.22).

CONCLUSION

The results support the hypothesis that ghrelin requires postgastric feedback, which may be regulated through insulin.