Cognitive factors in the dietary response of restrained and unrestrained eaters to manipulation of the fat content of a dish.

This study examined the dietary intake and rated internal state of 16 normal-weight young women following the manipulation of the actual or the presented fat and energy content of a test dish eaten at lunch. Half of the subjects were classified as restrained and half as unrestrained eaters. The test dish was either 2473 kJ (591 kcal) in its high-fat version or 1485 kJ (355 kcal) in its low-fat version, and was provided either with a correct or incorrect information about its fat content. All the intakes at the three meals during the following 8 h were covertly recorded in the laboratory, and internal state rated on four occasions. After the low-fat test dish presented as low-fat, unrestrained eaters increased their energy intake compared to that in other conditions. Restrained subjects did not exhibit this pattern and compensated for the missing energy in the low-fat test dish, compared to the high-fat test dish, only when they were informed that both dishes were high in fat. Irrespective of the information, both restrained and unrestrained subjects reported weaker sensations of hunger after the actual high-fat test dish than after the actual low-fat test dish whereas only restrained eaters reported stronger sensations of fullness. Thus, the influence of the cognitive factors on food intake and ratings of internal state is modulated by restrained eating behaviour.