Different postprandial plasma ghrelin responses elicited by intake of 6 commercial snack foods in healthy subjects

Snacking is controversially discussed as a good habit in a healthy nutritional regimen. Obviously snack foods may be very different in determining glycemic and hormonal responses related to appetite and satiety. Serving-size, composition, macronutrients are only some of the factors that could trigger a wide hormonal cascade and therefore causing potential deleterious effects on metabolism. In the last decade there has been a great deal of interest to consider ghrelin as a potential target for treating obesity. It has been previously shown that rodents vaccinated against endogenous ghrelin could slow weight gain by decreasing feed efficiency, thus suggesting a primary role played by this hormone in energy homeostasis. Here, 20 healthy individuals (10M/10F; BMI 23.3±1.6; 35±6 yrs) underwent to OGTT (50-g) and 6 isoglucidic test-meal loads to assess glycemic index (GI), plasma insulin and ghrelin circulating levels induced by 6 commercial snack foods. Ghrelin was significantly lower 3 hours after the snack intake with respect to the basal condition in half of the snack foods (hazelnut chocolate: P<0.001; sponge cake2: P<0.001; chilled cake: P=0.02), whereas no differences were detected in plasma insulin and GI among all snack foods. If ghrelin could be meant as a crucial biomarker of satiation, those 3 snacks drove a nutritional status more propending for a long-lasting hunger-free period. Our results indicate that snack foods are diverse in inducing plasma ghrelin levels under equivalent metabolic conditions. Further studies are needed to elucidate the role of ghrelin as hunger-hormone in the regulation of energy balance.