3. Lean protein
“Poultry and beans are associated with enhanced immunity,” Bazilian says. “Each is a good source of protein, zinc and iron, which are nutrients important for an effective immune response.”
Keep protein sources lean by removing the skin from chicken and turkey, choosing lean cuts of beef like round, sirloin and flank steak, and cooking beans and shellfish with minimal fat. In general, healthy adults should include 5 to 7 ounces of cooked meat, poultry or fish, or about 1 to 2 cups of cooked dry beans in daily menus.