The waist-to-height ratio (WtHR) is another tool to assess body size. Anyone assessing body size needs to take a person’s overall health status into consideration. Plus, body size is not a direct measure of health. Optimal WHR differs based on sex assigned at birth as well as race and ethnicity, according to the 2008 WHO report. For example, this measure does not account for a person’s total body fat percentage or their muscle-to-fat ratio accurately. However, as with BMI, the WHR does have limitations. Using WHR, a 2008 World Health Organization (WHO) report defines abdominal obesity as follows: They can then divide this measurement by the width of their hip at its widest part.įor example, if a person’s waist is 28 inches (in) and their hips are 36 in, they will divide 28 by 36, giving a WHR of 0.77. To calculate their WHR, a person should measure around their waist at the narrowest part, usually just above the belly button. A high WHR is has associations with higher levels of visceral fat, the fat in the abdominal cavity that surrounds several major organs.įor this reason, the WHR can be a useful tool for understanding potential health risks when considered alongside other assessments of health status.Ī 2018 meta-analysis suggests that having a high WHR can put people at a higher risk of myocardial infarction, or heart attack. However, it should not be the only measure an individual uses to assess whether their weight is ideal.Ī person’s WHR compares their waist size with that of their hips. This inaccuracy may lead to a misdiagnosis or an incorrect assessment of risk factors between individuals.īMI can offer a rough idea of whether or not a person is at a moderate weight, and it is useful for measuring trends in population studies. Studies have shown that non-Hispanic white, non-Hispanic Black, and Mexican Americans may have significantly different levels of body fat but the same BMI as people from other groups. They can have a high BMI because they have more muscle mass, but this does not mean they weigh too much for their height.Īnother limitation of BMI is that it does not distinguish between people of different racial or ethnic groups. For example, high performance athletes tend have a lot of muscle and little body fat. While it takes height and weight into consideration, it does not account for factors such as: What is the problem with BMI?īMI is a very basic measurement. If a person has questions about their child’s BMI, they should consult a doctor. The CDC’s BMI charts for children use percentiles that compare measurements with boys and girls of the same age and gender. To calculate a child’s BMI, a person can use the CDC’s calculator for children and teenagers. The CDC use both age and sex assigned at birth in its BMI calculations for people between the ages of 2–19 years.

This is because children typically grow larger with age.

BMI based on ageĪge is not a factor in BMI for adults, but it is for children. A person can talk with their doctor if they have questions about calculating or interpreting their BMI score. BMI is just one tool to understand body size, and it does not account for all of the ways that people’s bodies may differ.

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