Shore Health Systems

Home > Medical Reference > Encyclopedia (English)

Toggle: English / Spanish

Obesity - Overview

Alternative Names

Morbid obesity; Fat - obese

Definition of Obesity:

Obesity is a term used to describe body weight that is much greater than what is considered healthy. If you are obese, you have a much higher amount of body fat than is healthy or desirable.

Adults with a body mass index (BMI, calculated as weight in kilograms divided by height in meters squared) greater than 25 kg/m2 but less than 30 kg/m2 are considered overweight.

Adults with a BMI greater than 30 kg/m2 are considered obese.

Anyone who is more than 100 pounds overweight or who has a BMI greater than 40 kg/m2 is considered morbidly obese.

Causes, incidence, and risk factors:

Consuming more calories than you burn leads to being overweight and, eventually, obesity. The body stores unused calories as fat. Obesity can be the result of:

  • Eating more food than your body can use
  • Drinking too much alcohol
  • Not getting enough exercise

An underactive thyroid (hypothyroidism) may lead to weight gain, but usually only 5 - 10 pounds of weight. Some antidepressants and antipsychotic medicines may also contribute to weight gain and obesity. Genetic factors play some part in the development of obesity -- children of obese parents are 10 times more likely to be obese than children with parents of normal weight.

People who are at higher risk for obesity include:

  • Lower income groups
  • Former smokers
  • People with chronic mental illness
  • People with disabilities
  • People with a sedentary lifestyle
  • Reviewed last on: 10/15/2009
  • David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

References

Leslie D, Kellogg TA, Ikramuddin S. Bariatric surgery primer for the internist: keys to the surgical consultation. Med Clin North Am. 2007;91:353-381.

Richards WO, Schirmer BD. Morbid Obesity. In: Townsend CM Jr., Beauchamp RD, Evers BM, Mattox KL, eds. Sabiston Textbook of Surgery. 18th ed. Philadelphia, Pa: Saunders Elsevier;2007:chap 17.

Gardner CD, Kiazand A, Alhassan S, et al. Comparison of the Atkins, Zone, Ornish, and LEARN diets for change in weight and related risk factors among overweight premenopausal women: the A TO Z Weight Loss Study: a randomized trial. JAMA. 2007;297(9): 969-977.

Hughes AR, Stewart L, Chapple J, et al. Randomized, controlled trial of a best-practice individualized behavioral program for treatment of childhood overweight: Scottish Childhood Overweight Treatment Trial (SCOTT). Pediatrics. 2008;121(3):e539-546.

Thompson WG, Cook DA, Clark MM, et al. Treatment of obesity. Mayo Clin Proc. 2007;82(1):93-101

Svetke, LP, Stevens VJ, Brantley PJ, et al. Comparison of strategies for sustaining weight loss: the weight loss maintenance randomized controlled trial. JAMA. 2008;299(10):1139-48.

Kaplan LM, Klein S, Boden G, Brenner DA, Gostout CJ, Lavine JE, Popkin BM, Schirmer BD, Seeley RJ, Yanovski SZ, Cominelli F. Report of the American Gastroenterological Association (AGA) Institute Obesity Task Force. Gastroenterology. 2007;132(6):2272-5.

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.
adam.com