| Research indicates that food deprivation, a reduction of overall caloric intake, and food restriction, conditions in which cognitive or environmental controls have been implemented so that access to certain foods is limited, are associated with increased consumption, and that food deprivation increases the relative-reinforcing value of food. However, it is unclear if food restriction and the combination of food restriction and deprivation increase the relative-reinforcing value of food. Additionally, individuals with a history of food deprivation and restriction (restrained eaters) may respond to short-term food deprivation and restriction differently than individuals without this history (unrestrained eaters). Consequently, this study examined the effects of food deprivation, food restriction, and the combination of food deprivation and restriction on the relative-reinforcing value of food in restrained and unrestrained eaters. Using a 2 x 2 x 2 x 8 mixed design, 72, normal weight, college-aged females were randomized to one of four conditions: deprived/restricted, deprived/non-restricted, non-deprived/restricted, and non-deprived/non-restricted. All participants were at least 13 hours food deprived for the experimental session, and non-deprived participants consumed at least 365 from a drink, while participants in the deprived condition consumed nothing. Restriction was manipulated by placing snack food in front of participants for 15 minutes without providing access to the snack food, while this did not occur to non-restricted participants. Following the experimental manipulations, participants completed a choice task (computer game), that varied the probability of earning points for a highly rated snack food or a highly rated sedentary activity across eight trials, to determine the reinforcing value of the food. Mixed four-factor repeated measures analyses of covariance found a significant main effect of deprivation (p < .05) and trials (p < .001). Deprived participants earned significantly more food points than non-deprived participants. Additionally, food points earned in the last five trials of the game were significantly less than points earned in the first trial. This suggests that short-term food deprivation similarly increases the relative-reinforcing value of food in restrained and unrestrained eaters, but that short-term food restriction has no effect on the relative-reinforcing value of food. |
