In the United States, the number of people who are overweight or obese is alarming. As a result, many people are attempting to begin weight loss plans. When starting this process, people often hear the term body mass index, or BMI. Unfortunately, people fail to understand what BMI is, how to use it or what it means. Without an understanding of BMI, it is impossible to know if a BMI is healthy or not.
Definition
According to the CDC, BMI is a calculation based on a person's weight and height. It is considered a fairly reliable indicator of body fatness for most people. BMI does not measure fatness directly. However, it is used as an alternative to direct measures of body fat. BMI is is easy to calculate and inexpensive. BMI can be used to compare a person's weight status to that of others in the population and for health professionals to determine possible health risks.
Calculation
Calculating your BMI is not very difficult. According to the CDC, the formula for determining your BMI is: weight (lb) / [height (inches)]2 x 703. To do this calculation using a calculator, you simply multiply your weight in pounds by 703. Then divide this answer by your height in inches. Finally, divide that answer by your height in inches again. The answer you get is considered your BMI. If you are not comfortable calculating your own BMI, you can perform an internet search for a BMI calculator. These automatically calculate your BMI based on the height and weight you enter.
Interpretation
According to the CDC, adults 20 years and older should interpret their BMI using standardized categories. These categories are as follows: BMI below 18.5 is considered underweight; BMI between 18.5 and 24.9 is considered healthy; BMI between 25 and 29.9 is considered overweight; and BMI over 30.0 is considered obese. Therefore, a healthy BMI is one that falls between 18.5 and 24.9.
Reliability
BMI reliability can vary based on sex, race and age. The CDC states that a woman who has the same BMI as a man usually has more fat. They also state that a younger person with the same BMI as an older person tends to have less fat. Finally, the CDC makes note that athletes, who are highly trained, will have a higher BMI because of increased muscle mass, not increased body fatness. Overall, BMI is a fairly reliable method of determining how fat a person is.
Consequences Of High BMI
You should do your best to keep your BMI in the healthy range (18.5 to 24.9). When your BMI is higher or lower than this, you are at risk for developing health conditions. The CDC states that overweight and obese people have a greater risk of developing hypertension, dyslipidemia (abnormal cholesterol levels), type 2 diabetes, coronary heart disease, stroke, gallbladder disease, osteoarthritis, respiratory problems, sleep apnea and certain cancers.
Considerations
The CDC explains that just because your BMI is high does not mean you have a high percentage of fat. It does mean you are considered overweight, but not necessarily unhealthy. However, most people who are classified as obese on BMI charts have excess body fat. The Indiana State Department of Health advises that BMI is not the only indicator of health risk and needs to be weighed against factors like diet, physical activity level, waist circumference, blood pressure, blood sugar level, cholesterol level and family history. If you find your BMI does not fall in the healthy range, you should contact a healthcare professional prior to starting any diet or exercise program.
Member Comments