خیلی وسوسه انگیز برای مقاومت؟ موفقیت های گذشته در کنترل وزن به جای خویشتن داری غذایی مواجهه ناشی از غذا خوردن مهار شده را تعیین می کند

As the prevalence of obesity is increasing, many people resort to dieting to achieve a healthy body weight. Such dietary restraint has been suggested to cause counterproductive effects leading to disinhibited eating. However, it is more likely that dietary restraint is a by-product of previous difficulties in weight control and disinhibited eating. If so, disinhibition should be related more strongly to unsuccessful weight control than dietary restraint. This possibility was examined in the present study. Participants were exposed to palatable food or to neutral objects. Before and after exposure, we measured craving, general inhibitory control and inhibition of food-related responses with the Stop-Signal Task (SST), and food consumption during a taste test. Results showed that exposure increased craving in both successful and unsuccessful weight regulators. People who were successful at controlling their weight, however, were better able to regulate this temptation compared to unsuccessful weight regulators: while exposure to palatable food reduced inhibitory control over food-related responses and increased food consumption in unsuccessful weight regulators, successful weight regulators did not show such disinhibition. Dietary restraint did not influence any of these findings. Further, the exposure-induced difference in inhibition between successful and unsuccessful weight regulators was specific for food-related responses, as regulatory success did not influence general inhibitory control. Thus, while successful and unsuccessful weight regulators seem equally tempted by palatable food, those who are successful in controlling their weight seem better able to resist these temptations by exerting inhibitory control over appetitive responses toward palatable food.

As overweight and obesity is constantly increasing worldwide, many people resort to different dieting strategies. Maintaining a healthy weight and reducing one’s body weight over an extended period of time, however, seems difficult for most people (e.g., Jeffery et al., 2000, Mann et al., 2007 and Wing and Phelan, 2005). Further, many dieters who chronically try to restrict their food intake are characterized by frequent lapses of restraint especially when exposed to palatable food cues (e.g., Fedoroff et al., 1997, Herman and Polivy, 1980 and Jansen and Van den Hout, 1991), stronger positive attitudes toward palatable food (e.g., Houben, Roefs, & Jansen, 2010), and increased disinhibition (Nederkoorn, Van Eijs, & Jansen, 2004). Research findings such as these contributed to the belief that attempting to control one’s food intake and body weight has counterproductive effects and causes a pattern of disinhibited overeating. In contrast to this idea, dietary restraint in fact generally seems to be related to less overeating and reduced weight in the long-term rather than increased overeating and weight gain (Johnson, Pratt, & Wardle, 2012). Therefore, it is probably more likely that disinhibited eating causes increased dietary restraint rather than vice versa (Jansen et al., 2003, Johnson et al., 2012, Lowe, 1993 and Lowe and Levine, 2005). Specifically, people who experienced difficulty controlling their food intake in the past, are probably more likely to attempt to restrict their food intake in order to attain a reduction in body weight. In this case, dietary restraint should be merely a by-product of unsuccessful weight control and overeating rather than a causal factor leading to disinhibited eating. So what distinguishes people who are successful at controlling their weight from those who are unsuccessful in attaining and maintaining a healthy body weight? One of the key differences between successful and unsuccessful weight regulation probably involves self-control. Self-control (or inhibitory control) refers to the ability to inhibit a behavioral impulse in order to attain higher-order goals, such as weight loss and maintenance. Indeed, research has demonstrated that increased inhibitory control predicts increased weight loss during treatment (Nederkoorn, Braet, Van Eijs, Tanghe, & Jansen, 2006). As such, self-control may be intimately connected to successful weight control so that successful weight regulators are better able to control themselves in tempting situations where unsuccessful weight regulators are prone to indulge. In line with this idea, research has demonstrated that tempting, palatable food activates positive affect to the same extent in successful and unsuccessful weight regulators (e.g., Van Koningsbruggen, Stroebe, & Aarts, 2011). Hence, people who can successfully maintain a healthy body weight appear to be no less tempted by palatable food cues compared to unsuccessful weight regulators. However, in contrast to unsuccessful weight regulators, people who are successful at controlling their weight may be better able to regulate such positive, appetitive responses to palatable food cues. Indirect evidence for this idea comes from studies that have demonstrated that food intake is more easily regulated in line with dieting intentions when self-control resources are high. In contrast, when self-control resources are low, eating behavior is more strongly guided by appetitive reactions to palatable food such as positive affect (e.g., Hofmann and Friese, 2008 and Hofmann et al., 2007). Further, successful weight regulators have been found to activate a dieting goal in response to palatable food cues, while unsuccessful weight regulators seem to inhibit such dieting goals (e.g.,Fishbach et al., 2003, Papies et al., 2008, Stroebe et al., 2008 and Van Koningsbruggen et al., 2011). According to Fishbach and coworkers (2003), such facilitative links between palatable food cues and the higher-order goal of dieting develop when people are repeatedly and successfully able to exert self-control in tempting situations. Together, these findings suggest that successful weight regulators are better able to inhibit appetitive responses to palatable food cues in situations where unsuccessful weight regulators exhibit disinhibition. Further, if dietary restraint is indeed merely a by-product of unsuccessful weight control, this relationship between inhibitory control and successful weight control should be uninfluenced by dietary restraint status. The aim of the present study was to test this hypothesis. Here, successful and unsuccessful weight regulators were either exposed to palatable food or to neutral objects. It was expected that such exposure to tempting, palatable food would reduce inhibitory control in unsuccessful weight regulators, but not in successful weight controllers, indicating that unsuccessful weight regulators are less able to regulate their behavior in tempting situations. Moreover, since the problem of disinhibited eating specifically pertains to the food domain, we also examined whether exposure to palatable food decreases general inhibitory control, or more specifically inhibitory control over food-related responses, in unsuccessful compared to successful weight regulators. Finally, we expected an increase in food consumption following exposure to palatable food in unsuccessful weight regulators but not in successful weight regulators.