A 3-ounce portion of sirloin steak contains 26 grams of protein and meets 37 percent of your RDA for niacin, 32 percent for zinc, and 9 percent iron. All that and only 54 mg of sodium. But nothing in life is free, and the American Institute for Cancer Research recommends that men eat no more than 18 ounces (cooked weight) of red meat per week. Also, research suggests that cooking meat over high heat, like grilling, may increase the risk of certain types of cancers. “Look for 93 percent lean cuts, such as loin or round, and descriptors like select versus prime, which are less marbled or fatty," says McDaniel. Always look for beef from "pastured" animals, which spend their lives grazing (so you get high levels of healthy omega-3 fats). If you can't find that, go for "grass-fed."