You’ve all seen it…..the skinny person who has no muscle tone, and the heavy person who’s solid as a rock. You may be overweight, but you might not be overfat. The trend in the fitness and health industry is slowly switching from the scale to the body fat calipers.
When someone says they are overweight, they are most likely comparing their weight to an “ideal weight” chart that they might have seen at their doctors office, or a magazine. For many years this was, and still is, the method of determining whether or not you are at risk for certain diseases. Insurance companies still ask for height and weight, but they don’t ask for the most important factor of all: Body Fat Percentage.
The human body is made up of 2 types of “masses”: body fat mass, and lean mass. Body fat is just as it sounds: fat. Lean mass is everything in the body that is not fat – muscle, water, bones, etc. The “ideal weight” charts do have some validity, since the majority of people who are overfat are overweight, but that still leaves a high number of people who have so much muscle mass, or a large bones structure, that they are over their “ideal weight”, but their body fat percentage is right in line with being “healthy”.
For example, a 5’2″ woman has an ideal weight of 110, but weighs 130. She eats a low fat diet and lifts weights 3 times a week. Her body fat percentage is a healthy 22%, yet she still thinks she’s overweight. Now she could stop lifting weights and go on a calorie restricted diet to lose some weight, but at 22% body fat she’d most likely lose muscle, since her body fat is already at a relatively low level. Once she loses muscle mass her metabolism slows down (the more muscle you have the higher your metabolism is) and she is no longer able to eat the same amounts of food. By losing muscle mass, she is also losing the ability to burn fat at the levels she did when she lifted weights, because more muscle = more mitochondria. The mitochondria is where we extract oxygen, which is critical to the fat burning process.
Along the same lines, someone who is paper thin might have such little muscle mass that they are overfat. As much as people like to be “thin”, thin doesn’t necessarily mean healthy. Someone who is 5’4″ and weighs 110lbs might be considered underweight, or “thin”, but if she never exercises and eats a lot of high fat foods, chances are she is the average 32% fat….which is NOT healthy. Because of the lack of muscle mass, she appears jiggly, even in her thin state.
So what is a healthy percentage of body fat?
For men, healthy is considered 12-18%, and for women the healthy range is from 16-26%.
You can have your body fat tested at most health clubs and recreation centers by certified personal trainers. To test your body fat a trainer grasps skinfolds of your subcutaneous fat in three or more areas and measures the thickness in millimeters. They add the total millimeters together and come up with a value, and that value, in turn, corresponds to a percentage. That is your percentage of fat. Skinfold calipers are accurate to plus or minus 3.5%.
Soon there will be charts that tell you how many calories you should ingest according to your percentage of lean body mass, rather than your weight.