Not only does it taste good, beef is also a great way to fuel your body In the American diet, beef is the number one contributor of protein, zinc and vitamin B12, number two of vitamin B6 and number three of iron and niacin. To get the same amount of zinc that is found in a 3oz. serving of lean beef, you would have to eat 3 oz. servings of tuna meat. By supplying a nutrient bundle in every bite, eating beef is a great way to make your calories count.