An estimated 60 percent of Americans aged 20 years and older are considered overweight and one-quarter are considered obese. Being overweight means that you have an excess amount of body weight, including muscle, bone, fat and water. Being obese means that you have an excess amount of body fat.
Obesity significantly increases your risk of developing life-threatening conditions, such as heart disease, stroke, high blood pressure, type 2 diabetes and some forms of cancer. Each year, approximately 280,000 adults die from an obesity-related condition in the United States. Additionally, studies have shown that people who are overweight often suffer from societal discrimination, which may lead to depression, self-esteem and body issue problems.
Obesity is a complex and chronic disease with many causes. It is not simply a result of overeating. Research has shown that genetics can play a significant role in determining a person's body weight, particularly for morbidly obese people. Diet and exercise may have a limited ability to provide effective, long-term relief for obese people.
Factors such as the environment, metabolism, eating disorders and certain medical conditions also may contribute to obesity.
Research has shown that a person's genes play an important role in their tendency to gain weight. Just as some genes determine eye color or height, others affect appetite, ability to feel full or satisfied, metabolism, fat-storing ability and even natural activity levels.
There are several medically accepted criteria for defining morbid obesity. You might qualify for a bariatric procedure if you meet any of the following critiera:
Weigh more than 100 pounds over your ideal body weight.
Have a body mass index (BMI) of over 40. BMI is a number based on both your height and weight. It can help determine the degree to which a person is overweight and assesses their total body fat. The normal BMI is 20-25. Use our Body Mass Index Tool to check your BMI.
Have a BMI of over 35 and suffer from conditions such as high blood pressure or diabetes, related to being severely overweight.
There are countless weight-loss strategies available but many are ineffective and short-term, particularly for those who are morbidly obese. Among the morbidly obese, less than 5 percent succeed in losing a significant amount of weight and maintaining the weight loss with non-surgical programs — usually a combination of dieting, behavior modification therapy and exercise.
People do lose weight without surgery, however, particularly when they work with a certified health care professional to develop an effective and safe weight-loss program. Most health insurance companies don't cover weight loss surgery unless you first make a serious effort to lose weight using non-surgical approaches.
Reviewed by health care specialists at UCSF Medical Center.
Last updated
December 21, 2011
Bariatric Surgery Center
400 Parnassus Ave., Sixth Floor, Room A-655
San Francisco, CA 94143-0338
Phone: (415) 353-2804
Fax: (415) 353-2505
Obesity and Weight Management
1701 Divisadero St., Suite 500
San Francisco, CA 94143-0320
Phone: (415) 353-2105
Fax: (415) 353-7901
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