BMI or Body Mass Index, a ratio of weight to height, has long been considered one of the best measures for assessing overall health risk. Getting your BMI into a healthy range used to be considered a top health priority. However, recent research shows that there is a new sheriff in town: your waist-to-height ratio (WHtR). Studies now indicate that WHtR is a much better measure than BMI for assessing obesity and cardiovascular risk. Read on to find out why, and whether your WHtR is in a healthy range.
In a recent study presented in the Journal of Clinical Endocrinology Metabolism, the WHtR was the strongest predictor of cardiovascular risk and mortality. On the other hand, BMI was not always positively associated with cardiovascular risk. The results of this study discourage the use of BMI as a measure of health risk and encourage the use of WHtR.
BMI provides a guide to the relationship between a person's height and weight. However, having a high BMI is not always a telltale sign that one will be at greater risk for disease. For instance, many thin people who have low or normal BMI's still have heart attacks or die from strokes and many people who have high BMI's are in good cardiovascular shape (as the study above indicated). BMI does not take into account an individual's frame, gender, or the amount of muscle mass versus fat mass. For example, two people can have the same BMI, even if one is much more muscular and carrying far less abdominal fat than the other; this is because BMI does not account for differences in fat distribution.
The WHtR is calculated by dividing waist size by height, and takes gender into account. For example a male with a 32 inch waist who is 5'10? (70 inches) would divide 32 by 70, to get a WHtR of 45.7 percent. The WHtR is thought to give a more accurate assessment of health since the most dangerous place to carry weight is in the abdomen. Fat in the abdomen, which is associated with a larger waist, is metabolically active and produces various hormones that can cause harmful effects, such as diabetes, elevated blood pressure, and altered lipid (blood fat) levels.
Many athletes, both male and female, who often have a higher percentage of muscle and a lower percentage of body fat, have relatively high BMI's but their WHtR's are within a healthy range. This also holds true for women who have a "pear" rather than an "apple" shape.
The following chart helps you determine if your WHtR falls in a healthy range (these ratios are percentages):
|Ratio less than 35: Abnormally Slim to Underweight||Ratio less than 35: Abnormally Slim to Underweight|
|Ratio 35 to 42: Extremely Slim||Ratio 35 to 43: Extremely slim|
|Ratio 42 to 46: Slender and Healthy||Ratio 43 to 46: Slender and Healthy|
|Ratio 46 to 49: Healthy and Attractive||Ratio 46 to 53: Healthy, Normal, Attractive Weight|
|Ratio 49 to 54: Overweight||Ratio 53 to 58: Overweight|
|Ratio 54 to 58: Seriously Overweight||Ratio 58 to 63: Extremely Overweight/Obese|
|Ratio over 58: Highly Obese.||Ratio over 63: Highly Obese|
New research shows that the WHtR, not BMI, is the most accurate assessment tool for health risk. People with the most weight around their waists are at greatest risk of diseases such as heart disease and diabetes. Therefore, since you can't change your height, you should take special care to keep your weight and in particular, abdominal girth in a healthy range by eating nutritiously and exercising regularly.