Variety enhances food intake in humans: role of sensory-specific satiety.

Twenty-one subjects were studied to evaluate the effect of renewal of sensory stimulations of previously eaten foods on sensory-specific satiety and intake. The subjects ate French fries then brownie cakes ad libitum in three situations: "monotonous" - fries then brownies were consumed alone; "simultaneous" - condiments (ketchup and mayonnaise for the fries, vanilla cream and whipped cream for the brownies) were added during intakes; "successive" - after intake of fries alone, ketchup then mayonnaise were available with fries and, after intake of brownies alone, vanilla cream then whipped cream were offered with brownies. The quantities eaten in the "simultaneous" and "successive" situations were higher (p<0.001) than those in the "monotonous" one (1485+/-582 and 1682+/-777 kcal vs 1195+/-552 kcal, respectively). In the "successive" situation, hedonic ratings for fries diminished during intake but increased after the introduction of ketchup, leading to additional intake of fries. Similarly, hedonic ratings for brownies diminished during intake and increased after the introduction of vanilla cream leading to additional brownie intake (mayonnaise and whipped cream had no significant effect). Food variety, obtained by adding condiments can increase food intake in the short term. The mechanism by which food consumption is increased after the addition of condiments is introduced is at least partly related to the attenuation of sensory-satiety for a given food.