Ester Marsh: It’s not all about weight

Published 12:00 am Saturday, September 17, 2022

So many people are so focused on their weight that they forget the body is not just your weight. Muscles weigh more than fat, right? One pound of muscle is a lot smaller and denser than one pound of fat. To top that off, the body is made out of about 55-60% necessary water weight, and muscles about 75%. Let’s look at the different ways of finding out someone’s body composition, which can be defined as the relative proportion of fat and fat free tissue in the body. The following are the ones used:

Height and weight. This is the one you are probably exposed to the most. Most doctors’ offices use, or have used, this chart to look at your body composition. It’s quick, cheap and easy to do. However, more criticism of the accuracy of this chart has made many look for different ways to find one’s body composition.

BMI (Body Mass Index). It uses weight relative to height. It works for your “average” person. But when you look at an athlete with lots of muscles the BMI does not differentiate fat weight from fat-free weight, therefore putting a muscular athlete in the overweight or obese section of the chart.

Waist to hip ratio (you measure the inches of the hip and the inches of the waist). Doctors’ offices have started using this a lot more. This ratio represents the distribution of body weight, and perhaps body fat in a person. This is used a lot as an important predictor of health risks of obesity.

Skinfolds (my favorite). Determining someone’s body composition through skinfolds can be quite accurate if the person who is performing the task is properly trained in the use of skinfold calipers. It is not the exact measurement of your total body fat, it is still an estimate of the total body fat. Another way for accuracy is to stay with the same trainer. Even though the sites of measurements are all the same, the way each trainer “pinches” might differ.

Bioelectrical Impedance. It’s a noninvasive and easy way to assess body composition. The bioelectrical impedance passes a small electrical current (you can’t feel it) into the body and measures the resistance to that current. Fat is a “poor” conductor, containing little water. To make this measurement valid, don’t eat or drink within four hours of testing and no exercise within 12 hours of testing.

Body fat scale, with sensors under your feet that use the bioelectrical impedance like the one above. It’s easy to use and can give you an idea where you are instead just giving your weight.

Bod Pod (Catawba College has one). A device that kind of looks like an egg and measures how much air you displace and then uses a formula to determine how much is lean mass and fat mass.

Hydrostatic weighing. This is an underwater body composition assessment. A person is first weighed on land then submerged into a large tank of water on a special scale. Under water, the person has to breathe out all the air in their lungs while they are weighed under water and again formulas are used to determine lean mass and fat mass.

Height and weight, BMI and waist-to-hip ratio charts can all be found on the internet. Most sites you can actually “plug” your info in and it will give you immediate results.

My favorite, as I mentioned, and affordable is the skinfold test. When someone loses a lot of weight and their skinfold test didn’t change much it tells me they lost water and muscles.

On the other hand when someone’s weight didn’t change much but their body fat went down, I know they lost fat. Whichever one you choose, focus on health, the rest typically will follow.

Good luck in finding your favorite measurement! The best results are seen when you use the same way of measuring your body composition.

Ester Marsh is health and fitness director of the J.F. Hurley Family YMCA.

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