Posts Tagged ‘body-mass-index’

Is Body Mass Index (BMI) an Effective Way to Measure Obesity?

The other night I was watching Jamie Oliver’s Eat To Save Your Life where a selection of slightly over-weight to morbidly obese people were shown what eating the wrong foods are doing to their bodies.

For one of the demonstrations three men (one slightly over-weight, one obese and one morbidly obese) went through a test to see who was the fittest. It appeared that the obese man (who happened to be vegetarian) was the fittest out of the three.

So they went on to give each man a CAT scan to measure the fat inside their bodies. The surprising thing is that the obese vegetarian had considerably less fat than either of the other two men. The reason was that he also had a lot of muscle from playing rugby.

What is Body Mass Index (BMI) and How is it Calculated?

To determine the level of obesity for the show, BMI was calculated. BMI is calculated using your height and weight to give you an indication of how healthy you are. You then compare your score to those on a chart to determine whether you are over-weight or not.

The problem is that it doesn’t take into consideration muscle. People who work out at the gym, work in a manual trade or play sports will receive a high BMI score suggesting they are overweight. When in fact they are perfectly healthy.

What Alternatives Are There?

Because very few of us will ever get the opportunity to have a CAT scan purely for the purpose of finding out how much fat there is in our bodies, we need to look at some alternative for calculating our body fat percentage.

Calipers – This is the traditional method which you can have done by a professional in your local gym or do yourself at home. You use the callipers to measure how much fat you have under the skin (subcutaneous fat). The measurements are then put into an equation to provide you with the percentage.

If you want to do this at home the suggested calipers to use are by Accu-Measure as they have been recommended by Body-for-LIFE, EAS, & World Natural Bodybuilding Federation.

Although this is fairly accurate method of finding out the amount of fat in your body, it’s not 100%. The reason is that as we get older we produce more internal fat around our organs and calipers cannot measure this.

Weighing Scales – There are special scales that you can easily buy which emit a Bioelectrical Impedance Analysis (BIA). Don’t worry it’s totally harmless. It calculates the density of fat in your body by passing an electrical current through you. These currents pass through bone and muscles much more easily than fat, so the more resistance the currents experience, the less fat you have.

BMI may help give an indication to health but it has some serious flaws which make it worthless if you have a lot of muscle. Although callipers and BIA weighing scales are not 100% accurate they are a lot better and do allow you to chart changes and see the progress you are making. Many people who go to the gym to loose weight become disheartened when they don’t see any changes on regular scales. This is because although they are loosing fat, they are also are gaining muscle which weighs more.

There are certainly plenty of people who need to lose weight out there so it’s no surprise that there are weight loss camps popping up all over the place.  Most people tend to think of their appearance but of course there is a lot going on under the surface of your body that you can’t see with the naked eye.  However you should also know that there are some disorders that cause weight loss so you should be careful about this too.  There are many who enjoy going to weight loss clubs such as Weight Watchers but remember, if you stop going chances are you will become even fatter than you are now.