Wednesday, September 25, 2013

Use Waist to Hip Ratio: Weight is Overrated for Assessing Health


One simple measurement indicates health status and it isn't a scale. Waist to hip ratio (WHR) is a strong predictor of heart disease risk. It is also strongly connected to risk factors for heart disease and diabetes.

Even though weight is often the focus of many weight and health-oriented programs, it is a less effective indicator of health in most cases. As I have discussed before, fat location is typically more important than fat quantity. When it comes to heart attacks, heart disease, and diabetes, this is certainly true.

WHR represents two major areas of fat storage, with one being unhealthy (waist) and the other being benign or potentially healthful (hips). As waist to hip ratio increases, so do the negative health implications. While measuring waist to hip ratio is more involved than simply stepping on the scale, it requires no more than one to two minutes (look here for directions).

Relevant Research

Not all fat is created equal. All fat cells secrete proteins that affect inflammation. Visceral fat, which is the fat around our organs, secretes proteins (adipokines) that increase inflammation [1]. Our hips feature only subcutaneous fat, which simply means "fat under the skin." Subcutaneous fat produces more anti-inflammatory proteins. It also acts as a buffer, taking accepting fats (fatty acids) traveling through blood that could have been stored as visceral fat. This buffering process also likely helps enzymes and organs which assist in controlling blood sugar.

Weight fails to distinguish where a person's fat is located. That's why it is such a poor indication of health. When eliminating the influence of WHR on weight, researchers found that weight is a weak predictor of heart disease risk [2]. However, WHR was much more accurate. When weight was eliminated as an influencing factor, the men and women with the largest WHRs were still 55 and 91% more likely to develop heart disease over a nine-year span.

Another study showed that, when split into fifths by weight, those in the heaviest weight group were 44% more likely to have a heart attack than those in the lowest group [3]. However, when divided into fifths by WHR, people with the highest ratio were 252% more likely to have a heart attack than those with the lowest ratios!

Fat location also represents a number of disease risk factors. More abdominal fat is associated with higher blood sugar following meals [4] and the presence of insulin resistance [5], a condition that precedes diabetes. Triglyceride levels in blood are also tied more to abdominal fat than total body fat [6]. On the other hand, more thigh fat is usually paired with health positives, such as lower levels of insulin in blood (a good sign for preventing diabetes) [1] and lower risks for heart disease and heart attacks [2, 3].

Final Thoughts

I'm not saying WHR ratio is perfect and for everyone. WHR, like the scale, does not distinguish lean tissue (muscle, water, bone, etc.) from fat tissue. In addition, some people aren't concerned with improved health as a goal (i.e. a 21 year-old guy looking to build muscle). If health is not a focus, then WHR is unimportant. WHR also does not distinguish between the type of fat in your midsection, whether it is surrounding organs or the benign subcutaneous kind. However, as midsection size increases, it's likely that visceral fat is increasing as well, which is why WHR is generally useful as a health measure.

WHR ratio is an accurate measure to take inbetween blood tests and doctor's visits if health is one of your primary goals. It is an effective way to predict your risk of heart disease and diabetes. Weight and many body fat tests fail to distinguish fat location, which is why they are poor methods for assessing health.

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