Metabolism Changes With The Aging Process

Do you need another reason to look forward to the aging process? Well you will not have to look far!

Metabolism is the rate at which the body burns calories and uses energy. There are a variety of different calculators available online which will help you to determine your basal metabolic rate (explained below) and the factors which contribute to the speed of your individual metabolism. These factors will determine how much food you can eat before you start gaining weight.

Your basal metabolic rate, or resting metabolic rate, is the number of calories you burn by simply living. In other words, if you were to wake up in the morning and lay in bed all day, your basal metabolic rate counts the number of calories it would take to maintain your body. Some of the factors that go into your basal metabolic rate are determined by genetics while other factors can be affected by your activity level and the foods that you eat. (1)

Factors that contribute to the speed of metabolism include the function of your thyroid gland, the amount of lean muscle you have in your body and your initial resting metabolic rate. Although your thyroid gland may have been functioning well when you were younger more women than men, exactly 10 times more women than men, will be affected by a thyroid gland that no longer functions at optimal rate. Many will notice an unexplained weight gain and should see their physician for a thyroid blood test. (2)

Weight Training Increases Your Resting Metabolic Rate

The amount of lean body mass will also affect your metabolism because muscle burns more calories at resting rate than fats. A pound of fat burns between five and 10 calories per day while a pound of muscle will burn between 35 and 50 calories per day. Your physician and fitness trainer may recommend weight training in order to decrease your risk of osteoporosis but another benefit of weight training is that it increases your resting metabolic rate, allowing you to eat slightly more each day without gaining weight. (3)

This slowing of the metabolic rate actually begins around the age of 30. At that point your body burns approximately 2 to 4% less calories every 10 years. As fewer calories are burned, more are stored as fat. Then, when you make no other changes you start to gain weight and lose energy.

Some physicians believe that the majority of our muscle loss is related to inactivity. The basis of this metabolic slowdown is actually our own fault. The less lean muscle we have the more inactive we become and the years progress our metabolism plummets.

Dietitians use an indirect calorimeter to measure your metabolic rate or the number of calories you require to live each day. It is a short and inexpensive test. A generic basal metabolic rate can also be determined by using online metabolic calculators that do not take into effect the amounts of lean muscle mass or the function of your thyroid gland.

Here are a few ways to recharge your slowed metabolism

Exercise will increase the number of calories you burn for 15 hours after you have completed exercising and the amount of lean muscle mass you add will continue to burn calories at a higher rate than fat. By strength training two to three times a week you add lean muscle mass which increases the amount of calories you burn. Using 30 minutes of moderate activity five days a week will also help to increase your metabolic rate.

The body uses energy in order to digest food. Eating three meals per day can actually slow your metabolism in the long run so try the smaller meals every three to four hours throughout the day. If you are not able to increase your muscle mass then you must decrease your calories between 350 and 500 calories per day just to maintain the weight you are already at.

Doing just those few things, and recognizing that your metabolism slows as you age, will give you an edge over your friends and others. Watch your calorie intake, get plenty of exercise and eat small meals during the day in order to give you the best opportunity of maintaining your weight as you move into your 40s, 50s and beyond.

(1) Basal Metabolic Rate

(2) American Thyroid Association: Thyroid and Weight PDF

(3) Metabolism and Weight Loss: How You Burn Calories