Stress is another obstacle in the journey toward a healthy weight for patients with obesity.

A 2017 survey conducted by the American Psychological Association found that moderate to high levels of stress affect the majority of Americans.¹ While much attention has been given the physiological and genetic mechanisms behind unhealthy weight, less attention has been awarded the role of stress in weight gain and weight management for patients with obesity. 

To be sure, the stressors faced by most people today are predominantly psychological (e.g., financial worries, interpersonal relationship turmoil), rather than physical.  Despite this, the body’s reaction to stress is the same, namely the release of glucose into the bloodstream to fuel muscles for fight or flight, thus leaving many with the excess glucose-fueled energy that ultimately is transformed into body fat.² 

The link between stress and BMI has been clearly established, with research clearly showing a link between stress and weight gain. For persons with obesity, stress is another obstacle in their journey toward a healthy weight. Research has found four pathways to stress: cognition, behavior, physiology and biochemistry.² 

Pathways to Stress: Cognition, Behavior, Physiology and Biochemistry

When one is experiencing moderate to high levels of stress, cognitive processes such as executive functioning and self-regulation are disrupted. For example, in delayed gratification tasks where participants were told they could choose from a medium-sized portion of candy now or have a larger portion later, those who experienced more cumulative life stress were less able to delay gratification, and this delayed gratification yielded higher BMI compared to counterparts who were able to delay gratification. 

Stress has also been found to contribute to unhealthy eating, descreased physical activity, and sleep behaviors. For example, in the 2017 study conducted by the American Psychological Association,¹ 39 percent of participants reported overeating or choosing unhealthy foods in response to stress. Previous research has also found the same pattern wherein people choose foods with higher levels of saturated fat and sugar during stressful times at work.² Stress has also been linked to decreases in physical activity and the sedentary lifestyle coupled with unhealthy eating leads to increased weight. Stress also disrupts sleep. A 2017 study suggests that shorter sleep is linked to an increased likelihood of weight gain as well as poor food choices.³ It should be noted that the authors acknowledge the need for further investigation. 

Stress also negatively affects our physiology. For example, when stressed, cortisol levels increase, and the increased cortisol levels promote the creation of abdominal fat. Additionally, cortisol promotes the desire to eat by reducing sensitivity to leptin, regulating neuropeptide Y stimulation, and activating reward pathways.² Stress triggers a dopamine release, and because dopamine enhances one’s desire for food, a reward circuit is initiated wherein eating foods that are high in saturated fat and high in sugar elicits a “good” feeling, so one continues to eat these unhealthy foods in pursuit of a dopamine release.² 

In addition to cognition, behavior, and physiology, biochemistry is also negatively affected by stress. For example, there is some evidence to suggest that the hormones leptin and ghrelin are influenced by stress. Ghrelin stimulates the food-reward processes,² so when stress is high, ghrelin levels may be elevated. Research also suggests that patients with obesity, or those with unhealthy BMIs, may be leptin resistant, though further investigation is needed.² 

Pathways to Stress: Unhealthy Weight

It’s not uncommon for patients with obesity to feel stigmatized because of their weight. In a study examining the effect of weight stigma, participants who were randomly assigned to the weight stigma group experienced more stress and more negative emotions.^4,5 When one is experiencing weight stigma, cognitive processes are negatively affected, particularly executive function and self-regulation. Weight stigma has also been shown to negatively affect cortisol levels. Stress is part of a viscous cycle of weight gain wherein stress can lead to weight gain and weight gain can lead to stress, a seemingly endless feedback loop with the perception of no escape.

How can clinicians help their patients with obesity? Certainly, attending to the overall negative health effects of unhealthy levels of stress in their patients is important. However, also working with their patients to identify stressors and develop tools for constructively managing stress is also important. Recommending a Very Low Calorie Diet (VLCD) or Low-Calorie Diet (LCD), meal replacement options, and lifestyle changes — namely stress management tools — are effective first steps toward helping patients with obesity live an overall healthier life.  

Sources:

1. Stress in America: The state of our nation
2. Stress and obesity
3. The epidemiology of sleep and obesity
4. The psychological weight of weight stigma
5. The stress of stigma: Exploring the effect of weight stigma on cortisol reactivity