What your bathroom scale doesn't tell you

By Diana Rini, ACE-Certified Personal Trainer

Maybe you proudly display it in your bathroom, hide it under your bed, or stuff it between the extra pillowcases in your closet. Yet in this case out of sight doesn’t always mean out of mind.

You know it’s there, teasingly tempting you to stand on it, spin its wheels, and predict your fortune for the day. What’s this incredible object that tells us if we hit the jackpot or struck out again? Yep, it’s the standard bathroom weight scale.

Often the barometer measure of our daily moods, many people can be emotionally tied to the number they see on the scale. If you find yourself basing your daily fitness and nutrition decisions based on what the scale says in the morning, you may be likely to make unhealthy and unnecessary decisions for the rest of the day, namely skipping meals or exercising excessively.

Instead, fitness and health professionals will ask you to focus on how your clothes fit, how much energy you have, and importantly, to forget the scale weight and focus on your body composition. Body composition is the relative make-up of your body weight between body fat and lean tissue (which include muscle, bones, tissue, and ligaments). Let’s look closer why body composition is so important

First, let’s focus on a few principles:

1. The human body can fluctuate due to water retention; food, alcohol, and caffeine consumption; exercise levels; menstrual cycle, etc. This can vary as much as 5 pounds in one day!
2. One pound is equal to 3,500 calories. To lose 1 pound, you need to create a 3,500 calorie deficit, preferably over time (i.e., a 500 calorie deficit per day). To gain 1 pound you need to create a 3,500 calorie surplus, again preferably over time.
3. Because it is more dense, one pound of muscle is 1/3 the size of 1 pound of fat (Muscle and fat weigh the same – one pound of muscle weighs equal to one pound of fat.)
4. The standard weight scale does not differentiate between muscle weight and fat weight.

It can be very frustrating and distressing to work very hard at your fitness and diet programs just to feel like you are not making any progress because the scale is not moving or not moving as fast as you would like. However, focusing solely on body weight, you may not recognize your true fitness progress. Often, minor weight fluctuations aren't as real as the numbers would have you believe. This is where body composition comes in.

Let’s use the following examples to demonstrate some of these concepts.

Client A Client A ate perfectly on Tuesday. On Wednesday he was up three pounds!

Client B Client B ate two pieces of pizza and consumed one beer on Friday, in addition to a

normal eating day. On Saturday she was down two pounds!

If these examples were true changes in body composition, then the following should have occurred:

• Client A needed to eat 10,500 extra calories on Tuesday to see the three pound gain on Wednesday (3,500 x 3). Rationale: This is not possible since Client A ate perfectly and consumed close to only 1,500 calories, his daily caloric goal.
• Client B needed to create a 7,000 calorie deficit on Friday (3,500 x 2) to have lost two pounds. Rationale: This is not possible since she ate much more than normal. The deficit can’t be attributed to exercise, because even if she ran and burned 10 calories per minute, she would have had to run 700 minutes (almost 12 hours) to burn those extra calories!

To make matters more complicated, body composition naturally begins to shift after about the age of 25:

The average person gains about 1 pound of weight per year

The average person loses one-half pound of muscle per year

The average person gains 1.5 pounds of fat per year

Client C Client C is a 30-year old woman. Her scale weight is 130, versus 125 at age

25. She is sedentary. Let’s look at the changes in her body composition.

Scale Wt Body Fat % Fat Wt Muscle Wt
Age 25 125 25.0% 31.25 93.75
Age 30 130 29.8% 38.75 91.25

Even though she only gained five pounds, the net gain is actually doubled.

She gained 7.25 of fat and lost 2.75 pounds of muscle, an net body composition change of a 10 pounds.

Client D Client D is also a 30-year old woman. Her scale weight is 125, the same as at age
25. One year ago Client D starting weight training three times per week, performing cardio five times per week, and eating a well-balanced, nutritional diet almost every day.

Scale Wt Body Fat % Fat Wt Muscle Wt
Age 25 125 25.0% 31.25 93.75
Age 30 125 24.6% 30.75 94.25

Although the scale has not moved, there are significant changes going on:

• She halted the body’s natural reaction to gain five pounds
• She reduced her body fat from 25.0% to 24.6%
• She increased her muscle weight
• She decreased her fat weight

Hopefully, this is enough compelling evidence to get your body composition tested and to exercise regularly!

Should you throw away your scale?

Probably not, just use it as a gauge every few months. Your clothes and a keeping good food journal can tell if you if you are packing on the pounds and why. Combined with a comprehensive fitness program, a monthly body fat measurement should serve as a good judge of your tracking your body’s composition.