Although there are genetic and hormonal influences on body weight, obesity occurs when you take in more calories than you burn through exercise and normal daily activities. Your body stores these excess calories as fat. Obesity usually results from a combination of causes and contributing factors, including:
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- Inactivity. If you're not very active, you don't burn as many calories. With a sedentary lifestyle, you can easily take in more calories every day than you use through exercise and normal daily activities.
- Unhealthy diet and eating habits. Having a diet that's high in calories, lacking in fruits and vegetables, full of fast food, missing breakfast, and laden with high-calorie beverages and oversized portions all contribute to weight gain.
- Pregnancy. During pregnancy, a woman's weight necessarily increases. Some women find this weight difficult to lose after the baby is born. This weight gain may contribute to the development of obesity in women.
- Lack of sleep. Too little sleep can cause changes in hormones that increase your appetite. You may also crave foods high in calories and carbohydrates, which can contribute to weight gain.
- Certain medications. Some medications can lead to weight gain if you don't compensate through diet or activity. These medications include some antidepressants, anti-seizure medications, diabetes medications, antipsychotic medications, corticosteroids and beta blockers.
- Medical problems. Obesity can sometimes be traced to a medical cause, such as Prader-Willi syndrome, Cushing's syndrome, and other diseases and conditions. Some medical problems, such as arthritis, can lead to decreased activity, which may result in weight gain. A low metabolism is unlikely to cause obesity, as is having low thyroid function.
- Recognition of obesity as a disease. American Medical Association House of Delegates. http://www.ama-assn.org/assets/meeting/2013a/a13-addendum-refcomm-d.pdf. Accessed Nov. 4, 2013.
- Defining overweight and obesity. Centers for Disease Control & Prevention. http://www.cdc.gov/obesity/adult/defining.html. Accessed Dec. 3, 2013.
- Jensen MD, et al. 2013 AHA/ACC/TOS guideline for the management of overweight and obesity in adults. Circulation. In Press. http://content.onlinejacc.org/article.aspx?articleid=1770219. Accessed Nov. 17, 2013.
- Bray GA. Pathogenesis of obesity. http://www.uptodate.com/home. Accessed Nov. 16, 2013.
- What are overweight and obesity? National Heart, Lung, and Blood Institute. http://www.nhlbi.nih.gov/health/health-topics/topics/obe/printall-index.html. Accessed Dec. 3, 2013.
- Bray GA. Etiology and natural history of obesity. http://www.uptodate.com/home. Accessed Nov. 16, 2013.
- Bray GA. Health hazards associated with obesity in adults. http://www.uptodate.com/home. Accessed Nov. 16, 2013.
- Understanding adult overweight and obesity. National Institute of Diabetes and Digestive and Kidney Diseases. http://win.niddk.nih.gov/publications/understanding.htm. Accessed Nov. 16, 2013.
- Papadakis MA, et al. Current Medical Diagnosis & Treatment 2013. 52nd ed. New York, N.Y.: The McGraw-Hill Companies; 2013. http://www.accessmedicine.com/resourceTOC.aspx?resourceID=1. Accessed Nov. 16, 2013.
- Sacks F, et al. Comparison of weight-loss diets with different compositions of fat, protein, and carbohydrates. New England Journal of Medicine. 2009;360:859.
- Moyer VA, et al. Screening for and management of obesity in adults: U.S. Preventive Services Task Force recommendation statement. Annals of Internal Medicine. 2012;157:373.
- Bray GA. Drug therapy of obesity. http://www.uptodate.com/home. Accessed Nov. 16, 2013.
- Blumberg RS, et al. Current Diagnosis & Treatment: Gastroenterology, Hepatology, & Endoscopy. 2nd ed. New York, N.Y.: The McGraw-Hill Companies; 2012. http://www.accessmedicine.com/content.aspx?aID=55957514. Accessed November 16, 2013.
- Nelson DW, et al. Analysis of obesity-related outcomes and bariatric failure rates with the duodenal switch vs. gastric bypass for morbid obesity. Archives of Surgery. 2012;147:847.
- Weight loss and complementary health practices: What the science says. National Center for Complementary and Alternative Medicine. http://nccam.nih.gov/health/providers/digest/weightloss-science. Accessed Dec. 3, 2013.
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