A number of different studies have shown a link between anxiety and obesity, however, it is not known whether the obesity can contribute to feelings of anxiety or people with anxiety disorders may be at a higher risk for obesity.
One study, described in General Hospital Psychiatry, March/April 2008, and completed by the Division of Adult and Community Health in the Centers for Disease Control and Prevention, indicates that people with anxiety disorders are 30 percent more likely to be obese than those without anxiety. The results of the study also indicated that those people with depression and anxiety were less physically active.
Another study, published in the July 2006 issue of the Archives of General Psychiatry, also found a link between obesity and anxiety (as well as other mood disorders). This study found the link to be stronger in people that were college educated, were under 30 and were non-Hispanic white. This is possibly explained because of the social stigma placed on being overweight in some cultures, or subgroups, and more accepted in others. Although earlier studies showed women who were obese to have a higher incidence rate of anxiety, this study did not show a gender difference.
Is Obesity a Cause of Anxiety or Is Anxiety a Cause of Obesity
Gregory Simon, M.D. MPH, was one of the lead researchers in the July 2006 study. According to Dr. Simon, the results of the study did not indicate whether obesity was a cause of anxiety and mood disorders or if the reverse was true. "Many mechanisms could explain the relationship, and possibly more than one is involved. Some people eat more when they're depressed and some people eat less, for example," said Simon.
Professor Tony Jorm and colleagues at the Australian National University have been researching this topic for several years and plan to continue following thousands of people over a 20 year period of time to see if he can answer the question of whether anxiety comes before obesity or vice versa. According to Jorm, there are three reasons obesity may impact mental health:
Being obese is socially undesirable
Obesity causes physical problems and illnesses
People with obesity are less physically active
The study completed in Australia accepts that, among people seeking treatment for obesity, there is a high incidence rate of depression or mood disorders. These patients, however, have already indicated an unhappiness with their current situation and therefore, the numbers may not be indicative or accurate of the general population. When looking at samples from the general population, according to Jorm, "there really isn't any consistent relationship [between obesity and depression or anxiety]. In addition, Jorm and his associates were interested in the difference between obesity increasing negative thoughts or reducing positive thoughts. Altogether, Jorm and his associates interviewed 7000 people, in three separate age groups.
Through the interviews, Jorm found there were a series of problem facing people that were overweight:
Worse physical health
Less physically active
More financial difficulties
Women, in particular, faced more criticism from family members
According to his research, it is not the obesity itself causing the depression, anxiety or other mood disorders, it is the impact of obesity on physical and emotional well being that affected mental health. Physical health, however, seemed to have the most impact on mental health. Those people in poor physical health had the largest rate of depression or anxiety.
When all other factors were taken into consideration, according to Jorm, people that were underweight, rather than overweight, had a higher incident rate of depression or anxiety. However, since people that are underweight do not have the same number of physical problems, they are more able to cope with symptoms or mask symptoms of anxiety and depression.
Losing weight will help people to become healthier, but according to Jorm, it will not necessarily make them happier. In an indirect way, losing weight can help to reduce anxiety, by improving health and the other concerns associated with obesity and related to higher levels of anxiety.
No Clear Answer
Research studies continue to show a correlation between anxiety and obesity, however, there is conflicting data over whether obesity contributes to anxiety problems or anxiety contributes to obesity. Or it is possible Tony Jorm's theory is correct and that obesity is not the determining factor, but the problems associated with obesity are actually the contributing factors that increase anxiety and depression.
"Researchers Look into Obesity's Links to Anxiety and Mood Disorders", 2007, Feb 14, Author Unknown, Insight Journal Online Magazine
"Depression, Anxiety Linked to Obesity", 2008, March 5, Glenda Fauntleroy, Center for Advancement of Health
"The Obesity-Depression Link, 2003, May/June, Willow Lawson, Psychology Today
"Obesity, Mental Well-Being and the Possible Influence of Weight Loss", 2003, Sept 1, Norman Swan, The Health Report