#4 - Protein
In the United States today, protein deficiency is virtually nonexistent. In fact, most Americans are actually getting twice the protein their bodies really need.
Most of us only need 0.8 grams of protein per kilogram of body weight each day—that’s about 50 grams for someone who weighs 150 pounds—which most people achieve easily. (source)
Step #4 try not to consume too much animal protein because it contains saturated fat and cholesterol.