Health News

BMI limitations: Age and sex, body composition, and health

BMI alone cannot show whether a person’s weight is healthful, but using it in combination with other indicators can provide a more complete picture.

Age and sex

For adults ages 20 years and older, BMI incorporates weight and height, but it does not take age or sex into account.

A woman tends to have more body fat than a man with the same BMI. Likewise, an older person tends to have more body fat than a younger person with an equal BMI.

For these reasons, BMI may not give the detail necessary to determine whether a person’s weight is healthful.

If fat accumulates around the waist rather than the hips, a person may have a higher risk of heart disease and type 2 diabetes.

This risk increases with a waist size greater than 35 inches for non-pregnant women or greater than 40 inches for men, according to the Centers for Disease Control and Prevention (CDC).

To measure their waist, a person should:

Weight, obesity, and health risks

The following information, adapted from the NHLBI, may help indicate the risks associated with BMI and waist circumference.

The chart shows weight categories according to BMI, and the effects of higher waist circumference on the risks of type 2 diabetes, hypertension, and cardiovascular disease.



Men 40 inches or less

Women 35 inches or less

Men: 40 inches or more

Women: 35 inches or more

A doctor may also measure body fat composition.

The following issues can also increase the risk of developing heart disease, for example.

  • high blood pressure (hypertension)
  • high levels of low-density lipoprotein (“bad”) cholesterol
  • low levels of high-density lipoprotein (“good”) cholesterol
  • high levels of triglycerides
  • high blood sugar levels
  • a family history of early heart disease
  • physical inactivity
  • cigarette smoking
  • a high consumption of alcohol

A doctor will recommend that a person consider losing weight if they:

  • have a BMI of 30 or greater
  • have a BMI of 25–29.9 plus two or more risk factors


If a person has obesity or excess weight plus two or more risk factors, they may be at risk of a number of obesity-related health problems in the future.

Losing 5–10 percent of their current weight can reduce the risk of developing these health problems.

Some people are overweight but have no other risk factors, such as high cholesterol or high blood pressure. They should follow a healthful and varied diet, and get regular exercise to prevent additional weight gain.

Source: Read Full Article