Beyond the Bathroom Scale
A standard bathroom scale only tells you your total mass. It cannot differentiate between a pound of muscle and a pound of fat. Because of this, two people who both weigh 200 lbs can look entirely different; one might be a shredded athlete, while the other is highly out of shape.
Lean Body Mass (LBM) strips away all the fat tissue, calculating the total combined weight of your muscles, bones, organs, and bodily fluids.
The Importance of LBM
In clinical nutrition and elite sports, your Lean Body Mass is vastly more important than your total weight. Knowing your LBM allows you to calculate your basal metabolic rate with precision, and dictates exactly how much protein you must consume to maintain your muscle tissue.
The Boer Formula
While there are several equations used to estimate LBM (such as James or Hume), the Boer Formula (1984) is considered the most accurate mathematical model for modern populations.
LBM (Men) = (0.407 * Weight) + (0.267 * Height) - 19.2
Using LBM for Nutrition
Once you know your Lean Body Mass, you can set precise dietary targets. A universal standard for bodybuilders and athletes is to consume roughly 1.0 to 1.2 grams of protein per pound of Lean Body Mass (not total body weight) to maximize muscle growth.