A couple of days ago my son was not eating his dinner and my daughter piped in
“Jaiden eat the chicken, it has protein, it will give you energy”
I cringed a little but this myth has gotten legs over the years. If you are tired and need energy nothing can beat a big steak.
In fact this idea is not at all true. Carbohydrates are the choice of energy sources in the body the fact is that the simpler the carb the more likely your body is to break it down and use it. The way that I look at energy sources your body will use the following in order; glycogen stores in your muscles, sugar, starch, and then equally protein and fat.
Many people on a diet will try to cut down on all of their carbs and will try to lose weight. This works initially because the body uses up all of the easy to get carbs and then will then move on to eating away at fat and protein. After a while you will get tired as your body will be really craving some kind of simple carbs for energy and it is a struggle for your body to use protein and fat as quick energy sources. This problem is even more of a problem when you exercise as there are no easy ways to get energy for your workouts.
So now you see why I am always writing about how important it is to get protein in your diet, not for the energy but more to counteract your body eating away at the protein in your muscles as well as the fat on your body when trying to lose weight. Your goal should be to look healthy not to look starved and muscleless.
So yes your body can use protein for energy buy mostly as a last resort. The problem is that when losing weight your body will use the protein in your muscles for energy as well as the fat in your body. But it will not use that steak right away.