Overview of Obesity

Overview of Obesity

Facts about obesity

Overweight and obesity together represent the second leading preventable cause of death in the United States. Obesity is a serious, chronic disease that can inflict substantial harm to a person’s health. Overweight and obesity are not the same; rather, they are different points on a continuum of weight ranging from being underweight to being morbidly obese. The percentage of people who fit into these two categories, overweight and obese, is determined by Body Mass Index (BMI).

Public health professionals agree that overweight and obesity have reached epidemic proportions in this country. Public health officials say physical inactivity and poor diet are catching up to tobacco as a significant threat to health. According to the most recent data from the 2003-2006 National Health and Nutrition Examination Survey, one out of five or 17 percent of U.S. children, ages 6 to 19, are overweight or obese. In addition, more than one third of the US population is overweight or obese--35 percent of women and 33 percent of men. However, for the first time in decades, the prevalence of U.S. adult obesity is not rising.

BMI is a measure of weight proportionate to height. BMI is considered a useful measurement of the amount of body fat. Occasionally, some very muscular people may have a BMI in the overweight range. However, these people are not considered overweight because muscle tissue weighs more than fat tissue. Generally, BMI can be considered an effective way to evaluate whether a person is overweight or obese.

In adults, a BMI from 18.5 to 24.9 is considered normal while a BMI of more than 25 is considered overweight. A person is considered obese if the BMI is greater than 30 and morbidly obese if the BMI is 40 or greater. In general, after the age of 50, a man's weight stabilizes and even drops slightly between the ages of 60 and 74. However, a woman's weight continues to increase until age 60 and then begins to drop. When assessing a child's weight, the BMI is calculated and then plotted on a BMI for age percentile curve. The Centers for Disease Control and Prevention developed sex-specific BMI for age growth curves to account for a child's for body fat variances across ages and genders. Public health professionals classify a child overweight if his BMI for age percentile ranking is 85th to less than 95th percentile or obese if his BMI for age percentile ranking is greater than the 95th percentile.

Another measure of obesity is the waist-to-hip ratio (WHR). The WHR is a measurement tool that looks at the proportion of fat stored on the waist, and hips and buttocks. The waist circumference indicates abdominal fat. A waist circumference over 40 inches in men and over 35 inches in women may increase the risk for heart disease and other diseases associated with being overweight.

Consult your doctor with questions regarding healthy body weight.

What causes obesity?

In many ways, obesity is a puzzling disease. How the body regulates weight and body fat is not well understood. On one hand, the cause appears to be simple in that if a person consumes more calories than he or she expends as energy, then he or she will gain weight.

However, the risk factors that determine obesity can be a complex combination of genetics, socioeconomic factors, metabolic factors, and lifestyle choices, as well as other factors. Some endocrine disorders, diseases, and medications may also exert a powerful influence on an individual's weight.

Factors which may influence the occurrence of obesity include, but are not limited to, the following:

Health effects of obesity

Obesity has a far-ranging negative effect on health. Each year obesity-related conditions cost over 100 billion dollars and cause premature deaths in the U.S. The health effects associated with obesity include, but are not limited to, the following:

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