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 Overweight and Obesity
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Frequently Asked Questions (FAQs)

If you need help with the terms used here, see the Weight Control Information Network's Obesity, Physical Activity, and Weight Control Glossary.

What is the prevalence of overweight and obesity among U.S. adults?

Results from the 2003-2004 National Health and Nutrition Examination Survey (NHANES), using measured heights and weights, indicate that an estimated 66 percent of U.S. adults are either overweight or obese.

To read more about American adult overweight and obesity trends, visit

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What is the prevalence of overweight among U.S. children?

Results from the 2003-2004 National Health and Nutrition Examination Survey (NHANES), using measured heights and weights, indicate that an estimated 17 percent of children and adolescents ages 2-19 years are overweight.

To read more about childhood and adolescent overweight, visit

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What is the difference between being overweight and being obese?

Overweight and obesity are both labels for ranges of weight that are greater than what is generally considered healthy for a given height. The terms also identify ranges of weight that have been shown to increase the likelihood of certain diseases and other health problems.

For adults, overweight and obesity ranges are determined by using weight and height to calculate a number called the “body mass index” (BMI).

See the following table for an example.

Height Weight Range BMI Considered
5’ 9” 124 lbs or less Below 18.5 Underweight
125 lbs to 168 lbs 18.5 to 24.9 Healthy weight
169 lbs to 202 lbs 25.0 to 29.9 Overweight
203 lbs or more 30 or higher Obese

It is important to remember that although BMI correlates with the amount of body fat, BMI does not directly measure body fat. As a result, some people, such as athletes, may have a BMI that identifies them as overweight even though they do not have excess body fat. For more information about BMI, visit Body Mass Index.

For children and teens, BMI ranges above a normal weight have different labels (at risk of overweight and overweight). Additionally, BMI ranges for children and teens are defined so that they take into account normal differences in body fat between boys and girls and differences in body fat at various ages. For more information about BMI for children and teens (also called BMI-for-age), visit BMI for Children and Teens.

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What are some of the factors that contribute to overweight and obesity?

Researchers have found that several factors can contribute to the likelihood of someone’s becoming overweight or obese.

To read more about the factors that can contribute to overweight and obesity, visit

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How does being overweight or obese affect a person’s health?

When people are or overweight or obese, they are more likely to develop health problems such as the following:

The more overweight a person is, the more likely that person is to have health problems. Among people who are overweight and obese, weight loss can help reduce the chances of developing these health problems. Studies show that if a person is overweight or obese, reducing body weight by 5 percent to 10 percent can improve one’s health.

To read more about how being overweight or obese can affect health, visit

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What can be done about this major public health problem?

The Surgeon General has called for a broad approach to help prevent and reduce obesity. The Surgeon General has identified 15 activities as national priorities.

To read more about what can be done, visit

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What are the costs associated with overweight and obesity?

According to The Surgeon General’s Call to Action to Prevent and Decrease Overweight and Obesity, the cost of obesity in the United States in 2000 was more than $117 billion ($61 billion direct and $56 billion indirect).

To read more about the costs of overweight and obesity, visit

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What is being done by CDC to address the problem of overweight and obesity?

CDC and its partners work in a variety of ways to prevent and control obesity. A few examples of these efforts include:

To find out more about these efforts, visit

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What are some suggestions for losing weight?

Most experts recommend that someone attempting to lose a large amount of weight consult with a personal physician or health care professional before beginning a weight-loss program. The Surgeon General’s Healthy Weight Advice for Consumers makes the following general recommendations:

For more information about losing weight, visit

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How can physical activity help prevent overweight and obesity?

Physical activity, along with a healthy diet, plays an important role in the prevention of overweight and obesity (USDHHS, 2001). In order to maintain a stable weight, a person needs to expend the same amount of calories as he or she consumes.

Although the body burns calories for everyday functions such as breathing, digestion, and routine daily activities, many people consume more calories than they need for these functions each day. A good way to burn off extra calories and prevent weight gain is to engage in regular physical activity beyond routine activities.

The energy balance

The Energy Balance is like a scale. To remain in balance, the calories consumed (from foods) must be balanced by the calories used (in physical activity).

The Dietary Guidelines for Americans 2005 offers the following example of the balance between consuming and using calories:

If you eat 100 more food calories a day than you burn, you’ll gain about 1 pound in a month. That’s about 10 pounds in a year. The bottom line is that to lose weight, it’s important to reduce calories and increase physical activity.

For more information on the role of physical activity in preventing overweight and obesity, visit

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Page last reviewed: June 20, 2008
Page last updated: June 20, 2008
Content Source: Division of Nutrition, Physical Activity and Obesity, National Center for Chronic Disease Prevention and Health Promotion