Question

When calorie intake is low, proteins are the last resource the body uses for fuel. which statement gives the BEST reason for this?

A. Proteins produce little usable energy when metabolized
B. There are few proteins in the body
C. We ingest a very small amount of protein every day
D. When the body uses proteins as fuel, it is breaking down substances vital to its structure and essential functions

Answer 1

Proteins are used last for energy because their primary role is as the building blocks of tissues, and metabolizing them for fuel leads to tissue breakdown and body wasting.

Step-by-step explanation:

When calorie intake is low, proteins are the last resource the body uses for fuel. The best reason for this is that when the body uses proteins as fuel, it is breaking down substances vital to its structure and essential functions. Unlike carbohydrates and fats, proteins are not stored in the body for later use as fuel. Instead, they are the building blocks of body tissue and serve essential functions such as the formation of enzymes and antibodies. Using protein for energy leads to tissue breakdown and can cause body wasting, which is why the body utilizes carbohydrates and fat stores before resorting to protein catabolism.