Seeing that dreaded three-digit number on the bathroom scale can often make or break your day. Unfortunately, that number does not break down into how much of your weight is healthy and the amount that is potentially unhealthy. The healthy, necessary weight reflects your lean body tissue. The rest is fat mass, of which a certain amount is also needed. Lean body tissue refers to various parts of the body that contain negligible amounts of fat.
Your body is made of minerals, proteins, fat and water. When you have your body composition measured, it is divided into two components: fat and non-fat. If you are trying to lose weight, it is important to know how much of your weight is non-fat, lean body tissue. Often, with diets alone, the weight lost comes from lean body tissue and water, so a combination of diet and exercise will help boost your lean body tissue as you lose the fat weight.
Lean Body Tissue
Lean body tissue is comprised of many essential parts, including organs and bones. The muscles, tendons and ligaments are also considered lean body tissue. Lean body tissue is not completely fat-free, as your internal organs and your bones contain small amounts of essential fat. Lean body tissue should not be confused with thinness. Being thin simply means you weigh less than the recommended amount for your age and height. Being lean means you are within a healthy weight range with adequate muscle tissue to support your activity level.
Essential fat is located around your internal organs to protect and supply fuel to them and underneath your skin to insulate you. Women carry more essential fat than men to prepare a woman's body for childbearing. The formula for calculating body composition subtracts this small amount of essential fat from the excess fat and lean body tissue to provide an accurate reading.
Lean and Mean
Bathroom scales that use electrical impedance, hand-held devices, skin-fold measurements and underwater weighing are all used to determine body composition. These options calculate body fat based on total weight to determine the amount of lean body mass. A physician can use this information to provide guidance for healthy weight loss. Excess amounts of fat can lead to health complications including a higher risk of heart disease, diabetes and high blood pressure.
- University of New Mexico: Getting a Grip on Body Composition
- Human Physiology: From Cells to Systems; Lauralee Sherwood