The mirror can reflect unwanted changes as you get older. To many people, muscle seemingly turns to flab after the age of 50. In truth, muscle mass doesn't "convert" to fat at any age. However, aging and a sedentary lifestyle will cause muscle mass to decrease -- without exercise, you'll lose a half-pound of muscle mass annually. If you don't adjust your diet, fat can, simultaneously, increase, thus giving the appearance that your muscle has changed into fat.
It may be easier to imagine that muscle converts to fat than it is to face the reality that maintaining muscle mass is your personal responsibility. As pointed out by Dr. Karl S. Kruszelnicki of the long-running ABC radio series, "Dr. Karl's Great Moments," muscle cells and fat cells are totally different. Biologically, it is impossible for one to become the other.
It wasn't until the late 1980s that science put a name to the natural process of muscle loss associated with aging. Irwin H. Rosenberg, the director of the Jean Mayer Human Nutrition Research Center on Aging at Tufts University, coined the term "sarcopenia." Research suggests that physical inactivity isn't the sole cause of sarcopenia. Additional factors that could contribute to the condition include declining hormones and insufficient protein.
An active lifestyle helps to keep your body fit and your muscles flexible. Resistance training is the best way to counter muscle loss. The American College of Sports Medicine recommends an individualized training program based on your overall health and age. If you have a serious health condition such as hypertension or an acute illness, consult your physician for an assessment before beginning an exercise program. Develop a program of eight to 10 exercises that work all of your muscle groups. Start with one set of 10 to 15 repetitions, building up to two or three sets as you gain strength. Exercise at least twice weekly, resting at least 48 hours between sessions.
As you age, your hormone levels decrease. This can cause your body fat to increase. Aging also affects fat distribution. Fat can accumulate around your core, surrounding vital organs such as your heart and lungs. It is important to watch your intake of fat and LDL, or "bad" cholesterol, and to eat plenty of fruits, vegetables and whole grains. Protein deficiency has also been linked to muscle loss in older adults. The recommended daily value of protein for women ages 19 to 70 and older is 46 grams; for men of the same age range, it's 56 grams. In addition to getting protein from meat, eggs and other protein-rich foods, you can take protein supplements.
University of New Mexico: Sarcopenia: The Mystery of Muscle Loss; Chantal Vella, M.S. and Len Kravitz, Ph.D.