How does exercise improve the metabolism? How would you answer? We all know that exercise does, but how? Wouldn’t your body return to normal after the exercise is finished? How does eating more meals in the day increase the metabolism? How how how? It just does? There has got to be better answers than that, and there is. It’s hormones.
Ghrelin and Leptin
Ghrelin is a chemical released in the body that helps stimulate the feeling of hunger. It is released into the stomach and sends a signal to the brain that gives the desire to eat. Ghrelin is suppressed when we are full by another chemical called Leptin. Leptin suppresses ghrelin for about three hours, and then Ghrelin is released again. The buildup of ghrelin increases the desire to eat, until it’s suppressed through the hormone released when full -- leptin. These two chemicals work as a balance to help in our eating habits.
Ghrelin slows down the metabolism to facilitate the storage of energy in the body. This increases the amount of fat stored. This is an adaptation device to help in survival. If the body has to go for a long period of time without food, storage can help the body survive longer. It has been found that those who have improper diets and those with anorexia have higher levels of ghrelin.
Because leptin is in fat cells, obese people have higher levels of leptin – the appetite suppressant. Also eating more does increase the levels of leptin released in the body. Leptin is opposite of ghrelin and increases the metabolism.
With leptin in fat cells the body naturally tries to remove this excess fat by using leptin to suppress the apatite and increase the metabolism. Someone who is obese has an extremely high metabolism. In fact, someone who is 500 pounds is burning about 7000 calories a day. With a pound of fat being about 3500 calories and a 2000 calorie diet, an obese person’s metabolism can burn nearly 2 pounds of fat a day! That’s by only adjusting the diet!
