Overview of Obesity and Overweight

Weight control has become a serious issue for many people throughout the world. People who are obese or overweight are more likely to develop diabetes, coronary artery disease (heart disease, cardiovascular disease), and gallbladder disease, among other illnesses.

Overweight Man - Masterfile Image

Overweight/obesity increases the risk for high blood pressure (hypertension), problems with joints (e.g., arthritis), and breathing issues (e.g., asthma, sleep apnea [OSA]), as well as stroke (brain attack). People who are overweight also may suffer from emotional or psychological disorders—including depression—in a society that values being thin.

Incidence and Prevalence of Obesity/Overweight

According to the third National Health and Nutrition Examination survey, 97 million people in the United States are overweight or obese. The Mayo Clinic asserts that more than 300,000 people in the United States die each year from conditions worsened by excessive weight.

Click on this image for more information about current obesity rates in the United States from the Centers for Disease Control and Prevention (CDC).2011 Obesity Rates - CDC

Signs and Symptoms of Obesity/Overweight

The signs of obesity and overweight are often visual. A person can look in a mirror and notice heavier areas of the body, and clothing may no longer fit correctly. A visit to the doctor may lead to measurements of fat in the midsection. Recent studies have shown that excess weight in the midsection (belly or abdomen) increases the rate for health problems, such as heart disease.

Body mass index (BMI) is a reliable indicator of overweight/obesity in most people. BMI, which is calculated from a person's weight and height, may be used to help determine the risk for related health problems.

For more information about calculating BMI, please go to the Centers for Disease Control and Prevention (CDC) Department of Health and Human Services.

Obesity/Overweight Complications

Obesity and overweight can lead to a number of complications, including the following:

  • Cancer (Increased risk for colon cancer, rectal cancer, prostate cancer, gallbladder cancer, ovarian cancer, breast cancer, uterine cancer, and cervical cancer has been associated with obesity and overweight.)
  • Diabetes (Obesity is the number one cause of type 2 diabetes. Additional fat raises blood sugar and makes insulin less effective.)
  • Emotional issues (In societies that place great value on a thin appearance, people who are obese or overweight often suffer from depression, discrimination, and rejection in social situations.)
  • Fatty liver disease (When excess fats accumulate in the liver, inflammation can develop, sometimes leading to cirrhosis of the liver.)
  • Gallbladder disease (Due to higher cholesterol levels in the gallbladder, obese and overweight people are more likely to develop gallstones.)
  • Gastroesophageal reflux (GERD; The connection between the esophagus and stomach may become impaired, causing stomach contents to go back [reflux] into the esophagus.)
  • Gout and osteoarthritis (Extra weight can put pressure on joints, particularly in the lower back, knees, and hips. Eventually, the cartilage that cushions the joints starts to wear away, causing pain, stiffness, and deterioration.)
  • Heart disease
  • High blood pressure (hypertension; Extra fatty tissue needs oxygen and nutrients, putting more stress on artery walls because there is more blood flowing.)
  • Increased amount of fat deposits in the blood (This may interfere with blood flow to the brain and cause a stroke, or may narrow the coronary arteries and cause coronary artery disease.)
  • Urinary and reproductive problems (Women who are overweight may have an increased risk for urinary incontinence, irregular periods, and difficulties conceiving.)
  • Sleep apnea(In some cases, people who are overweight can stop breathing for short periods of time while they are sleeping because their necks are larger and airways narrower.)

Obesity/Overweight Diagnosis

A diagnosis of obesity/overweight involves taking a medical history and performing a physical examination. The physician often consults with the patient to determine genetic influences, related medical conditions, lifestyle issues, and emotional health concerns.

To measure obesity and overweight and the corresponding health risks, doctors may use the body mass index (BMI). This number is calculated by dividing weight in pounds by height in inches squared, and then multiplying the result by 703.

Medically speaking, a person with a BMI of 25 to 29.9 is considered overweight and a person with a BMI of 30 or higher is obese. Morbid obesity is a medical term used to describe the condition of being 50–100 percent, or 100 pounds, overweight. Patients who have a BMI of 39 or higher are considered morbidly obese.

If the doctor suspects that a medical condition may be causing a patient to gain too much weight, appropriate laboratory tests (e.g., blood tests) are conducted and treatment is planned accordingly.

Publication Review By: Karen Larson, M.D.

Published: 15 Nov 2006

Last Modified: 28 Sep 2015