DAN Medical Frequently Asked Questions
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Overweight and Obesity
>The terms overweight and obesity refer to a body weight in relation to height that is greater than is considered healthy; both conditions often (but not necessarily) result in a higher proportion of body fat, known as adipose tissue, compared with lean muscle mass. Overweight is applied to those with a somewhat elevated weight, and obesity to those who are extremely overweight.
Body mass index (BMI) is a common way of expressing the ratio between weight and height. The following equations are used to calculate BMI:
- 69% of adult Americans (more than two-thirds) are either overweight or obese.
- Adult obesity rates have more than doubled in just over 30 years, from 15% in 1976–1980 to 36% percent in 2009–2010.
- 10 years ago, the obesity rate was significantly higher among women than men; currently, the rates are essentially the same — within a few decimal places of 36% for both men and women.
>BMI is an important measure for understanding population trends, but it does have some limitations, as follows:
Accordingly, BMI is just one of many factors that should be considered in evaluating whether an individual is at a healthy weight — along with waist size, waist-to-hip ratio and a measurement known as "skin-fold thickness."
- It may overestimate the proportion of body fat in athletes and others with a muscular build.
- It may underestimate the proportion of body fat in older persons and others who have lost muscle mass.