Obese Woman, cross section

Image Caption : Obese Woman, cross section : Traditionally, obesity has been defined as a weight at least 20% above ideal weight. More recent guidelines call for classifying obesity by using the body mass index (BMI). BMI is calculated based on your height and weight. However, BMI may classify as obese some people who aren't overweight but who are heavily muscled or big-boned. It also doesn't take into account the person's age. Waist-to-hip ratios (WHR) may be a better indication of disease risk, because they indicate if you have a lot of dangerous visceral fat inside your abdomen. Some doctors feel it's possible to be classified as obese and still be physically fit.


Obesity means having too much body fat. It is different from being overweight, which means weighing too much. The weight may come from muscle, bone, fat, and/or body water. Both terms mean that a person's weight is greater than what's considered healthy for his or her height.

Obesity occurs over time when you eat more calories than you use. The balance between calories-in and calories-out differs for each person. Factors that might affect your weight include your genetic makeup, overeating, eating high-fat foods, and not being physically active.

Being obese increases your risk of diabetes, heart disease, stroke, arthritis, and some cancers. If you are obese, losing even 5 to 10 percent of your weight can delay or prevent some of these diseases. For example, that means losing 10 to 20 pounds if you weigh 200 pounds.

NIH: National Institute of Diabetes and Digestive and Kidney Diseases

The material on this site is for informational purposes only and is not intended as medical advice. It should not be used to diagnose or treat any medical condition. Consult a licensed medical professional for the diagnosis and treatment of all medical conditions and before starting a new diet or exercise program. If you have a medical emergency, call 911 immediately.