Increased variety in the food supply may contribute to the development and
maintenance of obesity. Thirty-nine studies examining dietary variety, ener
gy intake, and body composition are reviewed. Animal and human studies show
that food consumption increases when there is more variety in a meal or di
et and that greater dietary variety is associated with increased body weigh
t and fat. A hypothesized mechanism for these findings is sensory-specific
satiety, a phenomenon demonstrating greater reductions in hedonic ratings o
r intake of foods consumed compared with foods not consumed. Nineteen studi
es documenting change in preference, intake, and hedonic ratings of food af
ter a food has been eaten to satiation in animals and humans are reviewed,
and the theory of sensory-specific satiety is examined. The review conclude
s with the relevance of oral habituation theory as a unifying construct for
the effects of variety and sensory-specific satiety, clinical implications
of dietary variety and sensory-specific satiety on energy regulation, and
suggestions for future research.