Palatability and dietary restraint: effect on cephalic phase insulin release in women

The palatability of food has been shown to influence the cephalic phase reflexes. To determine if food palatability affects the magnitude of cephalic phase insulin release (CPIR) in humans, normal-weight women were asked to list foods that they found palatable and unpalatable. Subjects then stayed overnight in the hospital on two separate days. On each morning following an overnight fast, an intravenous line was inserted and arterialized venous blood drawn for the measurement of plasma insulin and glucose. Blood samples were taken prior to and following a modified sham-feed. Subjects sham-fed the palatable or unpalatable foods (that they had previously identified) for a 2-min period. Foods were administered in a counterbalanced order. During the protocol, hunger and food palatability were monitored. The Three Factor Eating Questionnaire was administered to assess eating attitudes. No significant difference in the magnitude of cephalic phase insulin release was found between the two treatments. However, a statistically significant correlation (r = 0.61, p < 0.05) was found between an individual's degree of dietary restraint as measured by the Three Factor Eating Questionnaire and the magnitude of CPIR. These data suggest that the sensory attributes of food may play less of a role in modulating CPIR than an individual's psychological attitude towards food.