Explain what happens to protein, carbohydrate, and fat when consumed in excess.

Question

What will be an ideal response?

Answer 1

When a person eats excess carbohydrate, the body will first store the excess as glycogen, but glycogen storage areas are limited and fill quickly. Because maintaining glucose balance is critical, the body uses glucose frugally when the diet provides only small amounts and freely when supplies are abundant. In other words, glucose oxidation rapidly adjusts to the dietary intake of carbohydrate. Excess glucose can also be converted to fat. This pathway is relatively minor, however. Still, new body fat is made whenever carbohydrate intake is excessive. Excess dietary carbohydrate also can displace fat in the fuel mix. When this occurs, carbohydrate spares both dietary fat and body fat from oxidation. So the excess carbohydrate contributes to obesity or at least to the maintenance of an overweight body.
When a person overeats protein, the body uses the surplus first by replacing normal daily losses and then by increasing protein oxidation. If excess protein is still available, the amino acids are deaminated and the remaining carbons are converted to ketone bodies, which are stored as fat in adipose tissues. Thus, a person can grow fat by eating too much protein.
Unlike with excess carbohydrate and protein intake, excess fat intake does not promote oxidation. Instead, excess dietary fat moves efficiently into the body’s fat sores. Almost all the excess fat is stored.