Protein is found in foods like fish, eggs, beef, whole wheat, milk, liver, soy beans, beans, peanuts, brown rice and peas. It is recommended that people over 60 take 1.2 g of protein per kg of body weight per day. This is necessary to maintain the lean body mass, and keep the immune system active. This intake should be reduced to 0.8 g if the person suffers from diabetes or kidney problems.