Eat more lean protein to stay full, boost immunity and build muscle. Protein should be about 20 percent of your calories.
Friend or For: Protein gives you the nine essential amino acids that make the immune cells and hormones you need to be healthy and fit. But you want to focus on the lean proteins, such as poultry, eggs and fish, which contain minimal amounts of heart-harming saturated fat. (They also blunt hunger and keep blood sugar stable.) The not-so-trim proteins, such as fatty cuts of red meat (ribs, T-bone steak and ground beef that’s less than 80 percent lean), are major sources of saturated fat.
Best Picks: Fish, shellfish, lean pork, lean red meat, legumes, low-fat dairy, eggs, nuts, poultry, and soy.
Cut Back On: Marbles meat, full-fat dairy, high-protein energy bars (which are often very high in calories)
Top Myths: Eating protein increases lean muscle mass. Protein helps you maintain muscle mass. But you’ll only increase muscle mass if you are strength training, because the nutrient helps repair the tiny muscle tears that occur. As your muscles rebuild, they get stronger.