An easy way to estimate body fat
Do you find yourself saying or thinking, "I want to lose weight"? In fact, what you want to lose is fat.
But how do you know whether what you’re losing is fat or muscle? When calorie restriction (especially extreme calorie restriction) is your only weight-loss strategy, a good percentage of what you lose may be lean muscle. When that happens, you’re actually getting fatter even though the number on the scale may be going down.
Why do you care?
When you lose muscle, you reduce your metabolic rate–which determines the number of calories you need throughout the day. That means once you reach your "weight-loss" goal, your maintenance level of calories has gone down. Now you’ll have to eat fewer calories just to maintain.
Even a small surplus adds up. Just 100 calories extra per day equates to 10 pounds of fat in a year. But if you maintain or even slightly increase lean mass (muscle, bone, etc.) while restricting calories, you’ll be able to eat more after reaching your goal without regaining the fat you lost.
The second reason is cosmetic. Have you ever seen someone who lost a lot of weight but still didn’t look especially healthy? Someone who went from being a large out-of-shape person to a smaller out-of-shape person? Shapely muscle is what gives a man or woman a good-looking, young body, and weight-training is the only way to build it.
Cardio is essential–for both health and calorie burn. But if you want to maintain muscle and create a good shape, weights must be part of the equation.
Finally, loss of muscle tissue is part of the aging process–if you are sedentary and don’t counteract the loss with muscle-building exercise. Scientists estimate the loss of lean tissue at around 1 to 2 percent per year after age 50. That’s one reason elderly people are prone to falls. (And have you ever noticed how elderly women often carry their handbag across their forearm, with their elbow bent? It’s because they’ve lost arm strength and it’s too difficult to bear the weight of the bag with the strap in their hand.)
How do you know whether you’re losing "weight" or fat? There are all kinds of ways to measure body fat, from bathroom scales that provide an estimate (but not very accurately) to measurement with calipers and underwater weighing. A good, low-tech method is the "Navy way," which plugs height and a couple of measurements (for women, neck, waist, and hip; for men, neck and waist) into an equation and spits out a number.
I read about the Navy way on Tom Venuto’s Inner Circle site, and Inner Circle website manager Kyle Battis has the appropriate calculator on his website Ask the Fitness Expert. Here’s a link to the calculator. Women should provide height and neck, waist, and hip measurements; men should input just height, neck, and waist. All numbers should be rounded off to the nearest quarter inch.
If you keep a log of both your scale weight and your body fat percentage, you’ll know exactly how successful your program is. If your body fat is going down and your lean mass is staying the same or increasing, you’re on the right track. By the way–congratulations are due to Kyle, who is getting married today!
