Obesity and Anxiety Disorder: Which One Comes First?

There is a well-known relationship between obesity and psychiatric illness that is quite complex. We know that over half of those with mental health disorders have obesity. Understanding the relationship between the two conditions is necessary to treat either condition effectively and to de-stigmatize both.

Anxiety disorder is the most common mental health condition in the United States, and it is estimated that over 30% of Americans suffer from an anxiety disorder at any point in their lives. Subtypes of anxiety disorder include generalized anxiety disorder (which is the most common), panic disorder, post-traumatic stress disorder, obsessive-compulsive disorder, and social anxiety disorder. In a 2019 survey conducted by the National Center for Health Statistics, 15% of the population had experienced anxiety symptoms in the prior two weeks of the study, with adults aged 18-29 being the most affected age group.¹

Is obesity a risk factor for the development of anxiety disorder? Does anxiety disorder cause physiologic changes that promote weight gain? Studies have shown a correlation between obesity and anxiety disorder, but the exact relationship between these disorders remains unclear.

The Interplay Between the Conditions

Behavioral Changes

Those with anxiety disorder often overeat to find comfort through food. Eating foods high in carbohydrates and fat leads to activating the reward pathway in the brain that reinforces this behavior. It is estimated that 38% of Americans respond to high stress by increasing food consumption.² Additionally, the manifestations of anxiety conditions, specifically panic disorder, may discourage physical exercise as an aerobic activity may mimic some features of panic attacks. Alternatively, those with obesity may face social stigma, which can increase anxiety symptoms and isolation.

Neurohormonal Factors

Anxiety disorders cause activation of the sympathetic nervous system, which triggers the body’s fight or flight response. The hypothalamic-pituitary-adrenal system is also activated, a feedback system that regulates response to stress, mood, and emotions. Through these pathways, excess production of cortisol (which is thought of as the stress hormone) and alteration of the balance between hunger and satiety hormones promote weight gain.³

Sleep

Anxiety tends to cause sleep disruption through difficulty with both sleep initiation and sleep maintenance. Poor sleep has been associated with being a factor that predisposes to weight gain. Fatigue that results from poor sleep leads to decreased physical activity and potentially overeating to improve one’s energy level. Additionally, more time spent awake creates more opportunities to think about food and be tempted to eat.⁴

Racial and Ethnic Disparities

Many studies have found racial disparities in the care of those with mental health conditions and with obesity separately. Additionally, some research suggests that under-represented minorities with concomitant psychiatric disease and obesity are less likely to have these conditions addressed by healthcare professionals. Language barriers, lack of health insurance coverage, and availability and cost of psychotherapy are contributing factors. Misdiagnosis is more common in ethnic and racial minorities, as many of our assessment tools were designed and validated using Caucasian patients or do not account for differences in educational and cultural backgrounds. Behavioral therapy may not be as effective in some cultures as sharing emotions or personal issues may be discouraged. Social stigma poses an additional barrier, further complicating the care of those with both conditions.⁵

The Effect of the COVID-19 Pandemic

Rates of obesity and anxiety disorder have escalated during the pandemic. Multiple factors have increased stress levels during the pandemic, including loss of employment, fear of illness, school closures, supply chain shortages, and inflation. Social isolation, particularly at the beginning of this period, led to a surge in the incidence of mental health conditions and the tendency towards emotional eating. Many have been more sedentary during this time due to remote work, the closure of gyms, and the lack of organized social functions. Preventative healthcare services were deferred, and resources were diverted to acute care and inpatient settings, limiting opportunities for mental health and weight check-ins with primary care providers.⁶

As pandemic restrictions have eased in recent months, it is essential for those suffering from anxiety symptoms and struggling with weight management to reconnect with healthcare providers to identify and address the factors discussed here. Understanding the complexity of the interrelationship between anxiety and obesity can empower those affected when talking about treatment options with their doctors.