Internal and external moderators of the effect of variety on food intake.

Many factors contribute to how much we eat. One such factor is the variety of different foods available. The current article reviews the variety literature with a specific focus on the factors that moderate the effects of variety on food intake and that moderate the processes that may underlie the variety effect (i.e., sensory-specific satiety and monotony). The moderators have been categorized as being of either an internal nature or an external nature. The literature suggests that internal moderators, including characteristics such as gender, weight, and dietary restraint, do not act as moderators of the variety effect. One possible exception to the absence of internal moderators is old age. Alternatively, external moderators, such as particular properties of food and the eater's perception of the situation, appear to affect the strength of the variety effect on intake to some degree. An evolutionary hypothesis may account for the distinct roles that internal and external variables play in moderating the variety effect. (PsycINFO Database Record (c) 2009 APA, all rights reserved).