You should base your protein intake on your weight, not your age, according to the American Journal of Clinical Nutrition. The recommended daily allowance (RDA) is 0.80 grams of protein per kilogram of body weight. Thats 54 grams of protein per day for a 150-pound adult. You might add lean protein like fish and chicken to your diet, and try to only eat small amounts of red meat. Also look for protein-rich veggies like beans, artichokes, spinach, corn and broccoli.