Relationship between hunger and plasma cholecystokinin during weight reduction with a very low calorie diet.

Based on a large number of studies in various species, cholecystokinin (CCK) is considered to function as an important regulator of satiety. The present study was undertaken to determine the relationship between hunger score and basal and postprandial plasma CCK secretion, in six obese subjects before and after weight loss with modified fasting. Modified fasting (modifast, 240 kcal/day) for ten weeks induced a mean weight loss of 23 kg. The hunger score was reduced by about 75%. However, basal and plasma CCK release induced by 80 kcal of modifast were not different before and after ten weeks of modifast treatment. Thus, the reduction of hunger during modified fasting is not mediated by circulating CCK.