Human growth hormone is a natural substance in the body that decreases substantially as people age. With lower levels, you often see fatigue, sagging skin, decreased memory, decreased muscle mass and other changes typically associated with aging.

But here's some advice on how to boost the quality and quantity of your life.

Today, the average life expectancy is pushing 80 years. With more years to live, people are exploring ways to add more life to their years.

Doctor Delgado says raising your human growth hormone levels could help.

"When you put somebody on growth hormone that's really deficient, their heart will work better, their muscles will work better, their memory will work better, their sleep will be better, their mood will be better," Dr. Delgado says.

Restricting calories, working out intensely, and reducing carbs will also boost HGH.