Allison Aubrey Selection of food for weight loss, copy space a_namenko/iStockphoto/Getty Images hide caption Protein is having a moment. From coffee chains adding it to lattes to food companies marketing protein cookies and snacks, to Health Secretary Robert F. Kennedy Jr. touting steak instead of cake, the noise around protein can make it hard to know what you actually need. And under Kennedy, the federal government updated the Dietary Guidelines to recommend a higher daily protein intake than before. But nutrition science makes it clear that protein is not one size fits all. Protein needs vary based on several factors including activity level, age and body weight. So, here's how to put politics and marketing aside, and personalize your optimal intake of this key nutrient. Our bodies rely on protein to do everything from building and repairing muscles, to making enzymes that help digest food, to producing antibodies that support immune function.…