Your body can only use a certain amount of protein each day. If you take in too much protein, you may gain weight. Each gram of protein has 4 calories. If you take in 100 grams of protein, but your body can only use 50 grams of it, your body will store the extra 200 calories’ worth of protein as fat.ome people believe that all foods move through the small intestines in 2–3 hours. Thus, they believe, even if you ate even the fastest type of protein that can be absorbed at a rate of 8–10 grams per hour, you could only absorb 25–30 grams of protein in one meal.