Is your BMI reading false?

How do you measure your weight?

A news release last week from the head of the Canadian Obesity Network suggested that some obese people are in fact healthy and do not need to lose weight. This of course flies in the face of logic, so let’s look at the facts and see if we can make sense of this statement.

Dr. Arya Sharma says that as many as one-third of people deemed obese according to their BMI (Body Mass Index, which is the relationship between height and weight) have no medically-determined risk factors for heart disease and should not be counselled to lose weight.

Dr. Sharma goes on to say that since most people gain weight back after they lose it, the practical advice would be to simply suggest they not gain any further weight. Here’s the challenge with this thinking:

First off, the BMI is NOT an accurate measurement of obesity and should never be taken as such. The BMI was a creation of the insurance industry, which uses it as part of actuarial tables to determine mortality risk when issuing life insurance policies. Only recently has the medical community begun to use it in the evaluation of obesity and related risk factors. Doctors use it because it is easy to measure.

In truth, the key measurement needed to measure obesity is body fat percentage – the percentage of fat compared to lean muscle, bones, organ tissue, water and fecal matter.

Here’s more: The BMI is known to be only accurate as related to body fat percentage for 68% of people. So the “revelation” that 1/3 of people measured as obese by their BMI are in fact not obese is no surprise to anyone with a wellness background.

Let me give you a typical example. On the BMI, almost all professional football linemen are obese, because the amount of muscle they have makes their weight in relation to their height “off the charts.” In fact however, most linemen have a body fat percentage of about 15-16%, which puts them right in the middle of the recommended range of 11-19% for men.

By comparison, running backs and defensive backs who are built for speed instead of muscle might be 5-10% fat.

So if you have heard that obese people might be healthy despite their weight, please disregard this info. You should measure body fat percentage.

There are several ways to do this. The most effective, but least practical are air and water displacement units, typically only found in research labs. More practical but slightly less accurate would be hand-held callipers. These can be purchased for less than $30 and are accurate for approximately 85-90% of people, when used by an experienced operator. Many gyms use this method.

Another method is electronic impedance scales or hand-held units, which can now be bought for less than $50 at most major department stores. These are about 80% accurate.

Both these methods are less effective for people with more than average muscle mass, or those who are highly obese. For these people, waist measurement can often be the best place to start.

Doctors have recently begun to promote the concept that women with a waist size less than 32 inches and a man below 37 inches are not overweight. I would suggest that these numbers are much too high, and that this scale should adjust for height. Obviously a 5-foot man and a 6-foor man should not be expected to have the same waist size.

There are also many free programs available on websites where you can get a body fat estimate based on specific measurements. We have one on our website at www.keepcanadaslim.com. Go there right now and find out how you are doing. It takes only a minute. This estimate will give you a starting point should you decide you want to change the shape you’re in.

Men should aim for 11-19%, women 17-23%, going as high as 25% if they are post-menopausal. High level athletes and those on a serious muscle-building workout program may be lower, although women who drop below 15% often stop having periods, which doesn’t seem to be a sign of health to me.

In closing, it is unfair to medical doctors to expect them to be experts in prevention. Doctors treat disease. The key point Dr. Sharma was making is that these patients have no sign of heart disease. Their blood pressure and cholesterol levels are within normal limits. Therefore doctors should not be using the resources of the medical system – which is under tremendous financial pressure – to “treat” them.

Unfortunately the extension of that is if left alone, these weight issues may eventually contribute to measureable risk factors, and then the person will be gladly accepted as a patient!

From a wellness perspective, we’d like to suggest people adjust their lifestyle to one that will prevent weight gain – plus adopt a shopping, cooking and eating program that will improve their health.

But don’t expect to find that program through our doctors.

In closing – forget the BMI!!!!!!!!!!!!!!