Weight Loss Home > Body Mass Index
The body mass index score is valid for both men and women, but it does have some limits. Body mass index may:
- Overestimate body fat in athletes and others who have a muscular build.
- Underestimate body fat in older people and others who have lost muscle mass.
In addition to body mass index, there are a number of different ways to measure body fatness. These other methods include:
- Skinfold thickness measurements (with calipers)
- Underwater weighing
- Bioelectrical impedance
- Dual-energy x-ray absorptiometry (DXA)
- Computerized tomography.
These other methods of measuring body fatness are more accurate than body mass index. However, these methods are not always readily available, and they are either expensive or require highly trained personnel.
Nearly two-thirds of adults in the United States are overweight (defined as having a BMI equal to or greater than 25). This means that about 130 million adults weigh more than they should. Nearly 61 million adults are obese (defined as a BMI greater than or equal to 30).
Even more concerning is that approximately 15 percent of children and adolescents are overweight, and another 15 percent are at risk for being overweight (BMI-for-age between the 85th and 95th percentile). Child obesity is a growing problem. An alarming number of children are obese and developing diseases normally seen in adulthood.
Less than half of US adults have a healthy BMI. This is equivalent to about 68 million adults. About 37 million women between the ages of 20 and 74 have an ideal body mass index. About 31 million men between the ages of 20 and 74 have an ideal body mass index.