Stress-induced eating in women with binge-eating disorder and obesity.

The purpose of the current study was to investigate stress-induced eating in women with binge-eating disorder (BED) and obesity. Three groups of women [obese with BED (n=9); obese non-BED (n=11); and normal weight (NW) non-BED (n=12)], rated their levels of hunger and psychological distress before and after completing the Trier Social Stress Test, followed by food anticipation and then consumption of their preferred snack food. We differentiated between the motivational and hedonic components of eating by measuring the amount of food participants poured into a serving bowl compared to the amount consumed. Stress did not affect poured and consumed calories differently between groups. Across all subjects, calories poured and consumed were positively correlated with post-stress hunger, but calories poured was positively correlated with post-stress anxiety and negative affect. These results indicate that stress-related psychological factors may be more strongly associated with the motivational drive to eat (i.e. amount poured) rather than the hedonic aspects of eating (i.e. amount consumed) for women in general. Exploratory correlation analyses per subgroup suggest that post-stress hunger was positively associated with calories poured and consumed in both non-BED groups. In the obese BED group, calories consumed was negatively associated with dietary restraint and, although not significantly, positively associated with stress-induced changes in anxiety.These findings suggest that stress-induced snacking in obese BED women may be influenced by psychological factors more so than homeostatic hunger mechanisms. After controlling for dietary restraint and negative affect, the NW non-BED women ate a greater percentage of the food they poured than both obese groups, suggesting that obesity may be associated with a heightened motivational drive to eat coupled with a reduction in hedonic pleasure from eating post-stress. Further studies that incorporate novel approaches to measuring the motivational versus hedonic aspects of stress-induced eating may expose nuanced eating behaviors that differentiate BED and obesity. If confirmed, our findings would support prevention and treatment strategies that target subsets of women based on obesity and BED status.

Binge eating disorder and obesity: preliminary evidence for distinct cardiovascular and psychological phenotypes.

This study investigated cardiovascular functioning, mood, and eating-related psychological factors at rest and in response to mental stress in three groups of women: 1) Obese women with binge eating disorder (BED; n=9); 2) obese non-BED women (n=15); and 3) normal weight (NW) non-BED women (n=15). Compared to both obese and NW non-BED women, obese women with BED showed heightened overall blood pressure and reported greater depression symptoms, perceived stress, and eating-related psychopathology. Additionally, obese women with BED reported greater overall negative affect and state anxiety compared to obese non-BED women. The heart rate response to stress was blunted in the obese BED group compared to the other groups, but this effect was no longer significant after controlling for baseline differences in depression. Correlational analyses revealed a positive association between stress-induced changes in hunger and cardiovascular measures only in obese women with BED. Longitudinal studies are needed to determine if stress dysregulation and stress-induced increases in hunger contribute to the onset and/or maintenance of BED. In particular, studies utilizing an additional NW BED control group are warranted in order to further examine the impact of BED above and beyond the impact of obesity on psychophysiological functioning and to inform the growing literature regarding stress-related factors that distinguish the BED and obesity phenotypes.