Healthy BMI Ranges

Your weight is one of the factors that determines your BMI.
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Having a healthy body mass index number is more important than the number on your scale. Your BMI is a quick calculation to determine if your body fat is within normal, or healthy, limits. While the BMI is not as accurate as other types of body fat testing such as underwater weighing, it provides a good place to begin looking at your overall health.

Body Mass Index

Your BMI is a number that results from a formula that uses both your height and weight. The number is a representation of body fat. It does not measure body fat directly but provides an overall guideline for weight concerns. If you want to calculate your BMI, divide your weight in pounds by your height in inches squared. Multiply the result by 703. If you measure your weight in kilograms, divide your weight by your height in meters squared.


A healthy BMI is between 18.5 and 24.9. If you are above this range, keep in mind that this number does not take into consideration muscle tissue. BMI calculations see weight as weight; not fat or muscle. Muscle weighs more than fat, so athletes tend to have higher BMI's. A BMI over 30 is considered obese.


Your doctor is concerned with your BMI because extra weight left unchecked leads to health problems such as high blood pressure, heart disease, risk for stroke and diabetes. Think of your BMI as a baseline from which to make lifestyle changes, if needed. If your BMI places you in the overweight category, aim to lose weight with a healthy diet and exercise program. On the other hand, if you fall into the underweight category, you are at risk for poor health, too, and conditions such as osteoporosis. Speak with your doctor regarding a safe way to gain weight.


Some arguments against the BMI calculations say that the method does not always determine obesity. According to a study in the May 2010 issue of "Obstetrics and Gynecology," reproductive-age women were not identified as obese when measured with current BMI standards compared to body fat measurements. If you see the scale continue to increase, speak with your doctor regarding the health issues of carrying extra weight and start an exercise program to avoid future health concerns.

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