Obesity Causes

Causes of obesity are rarely simple. On the surface, the cause of obesity seems simple enough: A person who consumes more calories than he burns through exercise or other activities gains weight.

This relatively simple reason for weight gain is complicated, however, by additional causes of obesity. There are links between genetics and obesity, as well as certain medications, environment and hormone levels.

Genetics and Obesity Statistics

Obesity statistics suggest a link between genetics and obesity. The Children’s Hospital at the University of San Francisco (2010) reports that a child with one obese parent has a 50 percent chance of becoming obese himself — he’ll face an 80 percent risk if both parents are obese.

Although genetics and obesity are connected, a family history of obesity doesn’t necessarily predestine people to weight gain. You may be able to cancel out genetic predispositions by getting regular exercise, maintaining a healthy diet and making good lifestyle choices.

Environment and Obesity

An individual’s environmental is more influential than the link between genetics and obesity. Other causes of obesity include how a family eats, exercises and views food. Unfortunately, many families associate food with comfort and special occasions, increasing the chance of overeating, and nurturing this relationship between environment and obesity.

However, the link between environment and obesity goes well beyond family attitudes toward food and exercise. Other environmental factors that encourage overeating and obesity include:

  • Easy access to large meals
  • Food advertising
  • Increase in sedentary desk jobs
  • Labor-saving devices (such as cars) that reduce physical activity
  • Less healthy food choices
  • Little time to prepare healthy food
  • Sedentary activities such as television watching
  • Urban environments that lack recreation facilities
  • Work schedules not allowing exercise.

Obesity and Hormones

In addition to genetic and environmental causes of obesity, recent studies have also shown a link between obesity and hormones. Abnormal hormone levels may contribute to weight gain if individuals have Cushing’s syndrome, hypothyroidism or polycystic ovarian syndrome.

The Cycle of Eating Disorders - Causes of Obesity

Remember, however, that this link between obesity and hormones accounts for only a small percentage of cases–roughly 2 percent, according to the Mayo Clinic (2010).

Medications and Obesity Statistics

Some medications may be causes of obesity, by affecting appetite or resulting in water retention, such as antidepressants, corticosteroids, neuroleptics or seizure medications.

Most causes of obesity can usually be traced to lifestyle habits. However, if you experience inexplicable weight gain, you’ll want to see a medical professional immediately. This could be a sign of cancer or another other serious health condition.


Consumer Reports. (2010). Medications that might cause obesity. Retrieved April 8, 2010, from http://www.consumerreports.org/health/conditions-and-treatments/obesity/what-is-it/medications-and-obesity.htm.

Mayo Clinic. (2010). Special report. Retrieved July 26, 2010, from http://www.healthsource.mayoclinic.com/secure/pdf/SRHW.pdf.

National Heart Lung and Blood Institute. (n.d.). What causes overweight and obesity? Retrieved April 7, 2010, from http://www.nhlbi.nih.gov/health/dci/Diseases/obe/obe_causes.html.

UCSF Children’s Hospital. (2010). Obesity. Retrieved April 8, 2010, from http://www.ucsfchildrenshospital.org/conditions/obesity/.