Answer courtesy of Justin Heaton, RD, LDN, multysite Campus Dietitian, Northwestern University

Protein plays an important role in every essential function of the body. It helps to build new cells, maintain tissues and create new proteins. It’s important for building and protecting our muscles. We find protein in a variety of food sources, both animal and plant-based. The best sources of lean protein are low in saturated fat and calories. Fish, like salmon, is a low-fat, high-quality lean protein that is rich in omega-3 fatty acids, which can help maintain a healthy heart. Poultry meat also makes an excellent source of protein. However, eating the skin doubles the amount of saturated fat – so go for the skinless, white meat for your best option. Eggs also make an excellent low-calorie, low fat source of lean protein. For animal-free sources, try beans, nuts, seeds and other whole grains. Team black beans up with brown rice for a complete protein source that is low in fat, and high in fiber and iron. Even beef can have its place in an overall healthy diet. Just go for the lean versions, like sirloin or top round. Lean proteins can easily become “unhealthy” proteins, so avoid frying, high-fat sauces and toppings, and aim for the baked, grilled or boiled varieties that will keep your food healthier!