Eat two sweet potatoes every week. This will provide you with the same amount of weekly beta-carotene as in men who demonstrated the lowest skin-cancer risk. Other top sources are carrots and cantaloupe.
Eat more protein. While you don’t have to go overboard on protein, there’s proof that a high protein diet helps when pushing your muscles to the limit. Tuna. Ounce for ounce, it’s one of the best sources of protein—and contains zero saturated fat.