By Wayne L. Westcott, Ph.D. and Rita La Rosa Loud, B.S.
Quincy – As we age, we tend to add bodyweight at the rate of 10 pounds per decade throughout young and middle adulthood. Unfortunately, the 10-pound per decade weight gain actually represents five pounds less muscle and 15 pounds more fat, for a 20-pound change in body composition. Consequently, what the bathroom scale indicates is a 10-pound problem is in reality a 20-pound problem.
While it is not advisable to add fat, it is even more problematic to lose muscle. Muscle loss leads to bone loss and musculoskeletal weakness. Less muscle tissue also results in a lower resting metabolism, which means that fewer calories are used throughout each day and that more calories are stored as fat. Because muscles function as the engines of our bodies, reduced muscle mass is closely associated with reduced physical capacity to perform activities of daily living.
After age 50, the rate of muscle loss increases up to 10 pounds per decade. For example, between ages
50 and 60, a post-menopausal woman could lose 10 pounds of muscle and add 10 pounds of fat without experiencing any change in her bodyweight. That is why we place much greater value on body composition assessments than on body weight measurements or body mass index (BMI) calculations. In the example above, comparisons of this woman’s body weight at ages 50 and 60 would show no difference, even though a 20-pound detrimental change in her body composition has taken place. The same is true regarding the popular BMI calculation. Assuming no change in height, this individual’s BMI reading would remain the same as BMI calculations consider only height and weight, not how that weight is comprised.
Basically, body composition consists of two components, namely lean weight and fat weight. Lean weight includes all of our vital tissues, such as muscle, bone, skin, blood, and organs. Ideally, lean weight makes up approximately 75 percent of a woman’s total bodyweight and about 85 percent of a man’s total bodyweight. The other component, fat weight, should make up about 25 percent of a woman’s total bodyweight and about 15 percent of a man’s total bodyweight.
Body composition is far more relevant to health and fitness than body weight. For example, Mary and Nancy are both 5 feet 5 inches tall. Mary weighs 120 pounds and is 33 percent fat. She therefore has 40 pounds of fat weight and 80 pounds of lean weight. Nancy weighs 140 pounds and is 25 percent fat. She therefore has 35 pounds of fat weight and 105 pounds of lean weight. Although Nancy weighs 20 pounds more than Mary, she has less fat and more muscle for a much better body composition and personal appearance, not to mention greater potential for good health and physical fitness.
Any reader who would like a body composition assessment in our Quincy College Exercise Science Center may call me at (617) 984 – 1716 to set up an appointment. We use a computerized ultrasound assessment system that causes no discomfort and is competed within two minutes. These is no charge for the assessment, which will provide a printout with your percent fat reading, actual fat weight, actual lean weight, and a recommended daily calorie intake to maintain or reduce your present body weight. We will also be pleased to provide information for safely and successfully reducing fat and rebuilding muscle through appropriate exercise and proper nutrition.
About The Author
Wayne L. Westcott, Ph.D., teaches exercise science at Quincy College and consults for the South Shore YMCA. He has authored 28 books on physical fitness and strength training. Rita La Rosa Loud, B.S., directs the Community Health & Fitness Center at Quincy College.
Categories: Senior Fitness