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Obesity Fact Sheet

According to the American Obesity Association, we all have and need fat tissue in our bodies. When there is too much body fat, the result is obesity. Obesity is not a sign of a person being out of control. It is a serious medical disease that affects over a quarter of adults in the United States, and about 14 percent of children and adolescents. It is the second leading cause of preventable death after smoking.

Obesity is as a chronic disease because it:

  • affects more than a quarter of the American population
  • causes many serious medical conditions
  • causes at least 300,000 deaths in the US each year
  • is the second leading cause of unnecessary deaths
  • carries annual healthcare costs of about $100 billion

According to a recent study by the RAND organization, obesity is more damaging to health than smoking, high levels of alcohol drinking, and poverty. Obesity affects all major bodily systems - heart, lung, muscle and bones.

Researchers have associated obesity to more than 30 medical conditions, and many agree that it is strongly related to at least 15 of those conditions.


  • Obesity increases CVD risk due to its effect on blood lipid levels.
  • Weight loss improves blood lipid levels by lowering triglycerides and LDL ("bad") cholesterol and increasing HDL ("good") cholesterol.
  • Weight loss of 5 percent to 10 percent can reduce total blood cholesterol.
  • The effects of obesity on cardiovascular health can begin in childhood, which increases the risk of developing CVD as an adult.
  • Overweight and obesity increase the risk of illness and death associated with coronary heart disease.
  • Obesity is a major risk factor for heart attack, and is now recognized as such by the American Heart Association.
  • Elevated BMI is reported to increase the risk of ischemic stroke independent of other risk factors including age and systolic blood pressure.
  • Abdominal obesity appears to predict the risk of stroke in men.
  • Obesity and weight gain are risk factors for ischemic and total stroke in women. 


  • As many as 90 percent of individuals with type 2 diabetes are reported to be overweight or obese.
  • Obesity has been found to be the largest environmental influence on the prevalence of diabetes in a population.
  • Obesity complicates the management of type 2 diabetes by increasing insulin resistance and glucose intolerance, which makes drug treatment for type 2 diabetes less effective.
  • A weight loss of as little as 5 percent can reduce high blood sugar.



  • Postmenopausal women with obesity have a higher risk of developing breast cancer. In addition, weight gain after menopause may also increase breast cancer risk.
  • Women who gain nearly 45 pounds or more after age 18 are twice as likely to develop breast cancer after menopause than those who remain weight stable.
  • High BMI has been associated with a decreased risk of breast cancer before menopause. However, a recent study found an increased risk of the most lethal form of breast cancer, called inflammatory breast cancer (IBC), in women with BMI as low as 26.7 regardless of menopausal status.
  • Premenopausal women diagnosed with breast cancer who are overweight appear to have a shorter life span than women with lower BMI.
  • The risk of breast cancer in men is also increased by obesity.


  • Obesity is strongly associated with cancer of the esophagus and the risk becomes higher with increasing BMI.
  • The risk for gastric cardia cancer rises moderately with increasing BMI.


  • High BMI, high calorie intake, and low physical activity are independent risk factors of colorectal cancer.
  • Larger waist size (abdominal obesity) is associated with colorectal cancer.


  • Women with obesity have three to four times the risk of EC than women with lower BMI.
  • Women with obesity and diabetes are reported to have a 3-fold increase in risk for EC above the risk of obesity alone.
  • Body size is a risk factor for EC regardless of where fat is distributed in the body.


  • Consistent evidence has been found to associate obesity with renal cell cancer, especially in women.
  • Excess weight was reported in one study to account for 21 percent of renal cell cancer cases.


  • Obesity is an established predictor of gallbladder disease.
  • Obesity and rapid weight loss in obese persons are known risk factors for gallstones.

Gallstones are common among overweight and obese persons. Gallstones appear in persons with obesity at a rate of 30 percent versus 10 percent in non-obese.

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