Why Is it Important to Maintain Muscle Mass While Losing Weight?

by Amy Kreger-Boynton

Overview

Are you losing water, fat or muscle with those inches, and why does it matter?

34f97ff7-1593-4b6e-a37c-ec9005b0a045500333

You've lost weight: congratulations! Did you lose water weight, body fat or lean muscle mass? Most folks shed a little bit of each during weight loss but not all pounds are created equally. Read on to discover the importance of maintaining muscle mass while losing weight.
Water

The body gives up water when stored carbohydrates are burned for fuel. This leads to the rapid weight loss commonly seen during the first few days of a typical "diet."

Fat Mass

Each pound of fat contains 3,500 calories, which are a unit of energy. During times of caloric deficit, the body taps into fat for fuel. In an ideal universe, every pound of weight lost on the scale would be fat, as excess body fat damages health in numerous ways.
Muscle Mass

To the body, in times of need muscle looks tasty. Full of protein building blocks, unused muscle "atrophies," or shrinks, during weight loss as it is cannibalized for fuel. Unfortunately, muscle is the last type of weight you ever want to lose.
Why Muscle Matters: Blood Sugar

Each time you contract a muscle, the cells within it consume carbohydrates for fuel. This leaves less sugar locked up in storage within the liver and muscles or floating around in the bloodstream. The pancreas, which regulates blood sugar, functions more effectively under these conditions, reducing the risk of diabetes.
Why Muscle Matters: Strength and Support

Muscle connects the bones of the skeleton, enabling motion while protecting vulnerable internal organs within your core. Strong muscles facilitate activities of daily living or "ADLs," making it easier to haul groceries, climb stairs, or play with your kids and pets.
Why Muscle Matters: Active Even at Rest

Have you ever heard a diet or exercise program promise to "burn calories even while you sleep?" Your muscles do just that. Even in a resting state, muscles use calories to keep themselves going, stoking the fires of your metabolism.

References & Resources

The American College of Sports Medicine's Resource Manual for Guidelines for Exercise Testing and Prescription; 2006