Metabolism

Metabolism is the rate at which your body burns calories and expends energy. Resting metabolism or basal metabolic rate is the amount of energy the body needs to keep you alive, i.e to pump blood, to breathe, resting metabolism is the largest component (typically 60-70%) of "energy out" in the energy equation.

Increase your resting metabolism (basal metabolic rate) by increasing lean muscle mass, it drives your resting metabolism.

Age and metabolism
As a person ages, his/her metabolism naturally slows down. This is a significant factor in weight gain, because of normal muscle mass atrophy and natural tapering off of hormones such as T3, human growth hormone and Testosterone.
most people give up as they age, but you do not have to accept this slow down. Through resistance and strength training, you can offset muscle atrophy and gain lean muscle mass or tone up, even as you age! some supplement can also safely and naturally support your hormone levels and help maintain metabolism
DHEA is a hormone precursor produced by the adrenal glands that may help the body retain youthful looks, energy and libido.

Exercise is also the key to using sugar as energy rather than storing it as fat. This is especially true past age 40. Exercise directly and immediately makes us glucose-tolerant and insulin sensitive, helping to prevent adult-onset diabetes as well as many other inflammatory diseases.
Author: O.A