Tuna is a delicious source of protein that can be enjoyed in many ways, especially on a sandwich. A single can of tuna contains over 40 grams of protein, providing over 80% of the recommended daily value and supporting healthy hair, nails, and skin. In addition to protein, tuna is rich in vitamins B6 and B12 and omega-3 fatty acids. Vitamin B6 helps break down food for energy and supports brain function, while omega-3s provide heart health benefits. For those who don't eat fish, nuts like walnuts and cashews are alternatives that also deliver protein and vitamin K.