While BMI should not be used as a substitute for professional health care, knowing your BMI can give you a good indication of whether you are on the right track as far as maintaining a healthy weight and body fat, no matter what your age or athletic capabilities are.
How is BMI Calculated?
While it does not measure body fat directly, it has been shown to correlate rather accurately with body fat measurements taken with more advanced technologies such as underwater weighing and x-ray machines. Because it is so simple, you can use BMI to look for weight problems that could lead to serious health conditions in the future.
To make things easy, BMI is calculated the same way for adults and children, men and women. A ratio between your height and weight, the body mass index formula looks like this:
weight (lb) / [height (in)2 ] x 703.
This translates to your weight in pounds, divided by your height in inches squared, and then multiplied by the number 703. Want an easier method for finding your BMI? Try our body mass index calculator and get your answer fast.
What To Look For
Now that you know your number, what does it really mean? The U.S. Centers for Disease Control in Atlanta provides this scale for interpreting your BMI:
Under 18.5 = Underweight
18.5 – 25 = Normal
25 – 30 = Overweight
Over 30 = Obese
Unlike measuring your weight, low is not always a good thing. For example, an extremely low BMI could indicate malnutrition or even starvation, and at the very least makes it difficult for your body to fight disease by lowering your immune system. While endurance athletes typically have a low BMI, the average person should strive for a BMI between 20 and 25. An average BMI is a sign of a healthy body, with the right balance between muscle, fat and bone density. People with normal BMI’s typically live longer and get seriously ill less often. An elevated BMI could be the first sign of serious health issues to come. Not meant to be cause of panic, taking steps to lower your BMI into the healthy range is something that you should seriously consider and discuss with your physician.
While BMI is calculated using the same formula for men and women, there are some discrepancies between the two. At the same height and weight, a woman will have a higher body mass index than a man. Likewise, highly athletic people may have a slightly higher BMI than a less athletic person because muscle mass contributes directly to your overall body mass index. However remember, since BMI is not a direct measurement of body fat, it is quite possible for a person with a higher BMI to have a lower body fat content than another, less athletic person. Body mass index is one tool in the health and weight management toolbox and should not be considered the only indicator of a healthy body.
Relationship Between BMI and Overall Health
Body mass index is a snapshot of your body’s balance between height and weight. It is a simple thing that if examined more closely, can reveal the potential for serious health risks associated with obesity. While a person with a BMI of 35 isn’t necessarily unhealthy today, she has the increased potential of developing obesity-related illnesses such as cardiovascular disease, diabetes and arthritis. According to the CDC, obesity is also directly related to certain cancers, particularly those that affect women, such as breast cancer and endometrial cancer.
People who are overweight suffer from increased levels of pain as well. Their joints will wear out sooner, their knees may need replacing, and their backs will ache. Carrying excess weight for an extended period of time is a leading cause of heart attack and stroke and just because your cholesterol count is low today, it doesn’t mean that will always be the case.
Many people use their body mass index calculations to assess their fitness levels, in addition to stepping on the scale. For years people have been obsessed with a certain weight range when instead they should be striving for a particular fitness level. BMI is the perfect tool for measuring that fitness level. Because it takes height into direct consideration, it is often a more reliable tool for measuring fitness than the 15- to 20-pound weight range that is provided based on age and gender.
As you grow older your BMI can be less reliable in determining fitness. On average, older people have higher body fat stores than younger people, even when measuring the same BMI. As a result, older adults should always discuss their fitness goals with their physicians and not rely solely on their body mass index calculation.
If you are looking to improve your overall level of fitness and dread getting on the scale, calculate your body mass index and measure yourself against the health community’s standard of ideal BMI. If you find your BMI high, take steps to reduce excess weight and increase your lean muscle mass. This is the perfect time to get out of the house and take a walk in the evening or go for a bike ride with your family. If you have young children, take them to the park and instead of just watching them, join them on the swings and jungle gym. You will be amazed at how quickly a few extra pounds can disappear, lowering your BMI and improving your chances of a long and healthy life.