Stress Effects on Body Weight
Stress often causes changes in eating patterns and choices. This has been studied for years. Understanding stress-induced eating changes is important because stress can trigger relapses into obesity as well as eating disorders. Stress may also be a component of a broad range of obesity risk factors and, thus, may contribute to the increasing prevalence of obesity.
During stressful periods, some individuals increase their eating (particularly of saturated fat and carbohydrates), whereas others reduce their eating. Habitual dieters tend to eat more when stressed, whereas food intake is the same or lower in non-dieters. It is theorized that reliance on cognitive control over eating, such as calorie counting or macro tracking, rather than physiological cues, feeling full or feeling good after eating, leaves dieters vulnerable to uncontrolled eating when these cognitive processes are disrupted, such as during stressful situations. Therefore, eating patterns of dieters often consist of periods of chronic dieting interrupted by episodic bingeing, and this exposes them to the risk of weight gain. This may be part of avoidance behavior to reduce the impact of stress, i.e., comfort food may enhance mood, at least in the short term.
In a study published in Obesity journal1, researchers examined the effects of stress on BMI and weight change in response to stress. The study involved 71 healthy female nurse practitioner students, and the natural stressor of academic examination at the end of a 12-week semester.
At the end of the semester, there were significant changes in BMI, stress management, dietary restraint, binge frequency, anxiety, and depression over the 12-week period. Of the subjects, 40 gained weight during the semester, 20 lost weight, and in 12, weight remained stable. The group that gained weight had the highest initial BMI and were more likely to be chronic dieters. In this group of 40 individuals, the exam stress was associated with significantly increased BMI. Furthermore, in this group, a significant reduction in dietary restraint was associated with a significant increase in adverse eating behaviors such as preoccupation about body shape, weight, and bingeing. This was coupled with an increase of anxiety/depression and a decrease in eating control. These same symptoms were not seen in individuals whose body weight remained stable or decreased. The findings are also predictable; people with the highest dieting behaviors are those with the highest initial BMI, and secondly, when these individuals are stressed, their dietary restraint decreases, and their BMI increases due to overeating.
To mitigate the effects of stress induced weight gain, these researchers recommend not only stress coping skills but also stress mastery. Understanding how to identify and control stress reactions can lessen its negative effects. Learning to be aware of and control stress responses takes intention, awareness, and practice over time. Learn more about stress and stress mastery techniques in our membership.
1 Doi: 10.1038/oby.2007.363