Another food source that is high in protein is nuts. Nuts are known to be protein and fat-rich, providing plenty of health benefits for seniors. Nuts also make a great snack for seniors who enjoy eating between meals. The only downside to this food is that nuts are quite hard and crunchy. This can be difficult to chew for seniors who do not have all of their teeth. One way to get around this is to use nut butter instead of whole nuts. You can use peanut butter or almond butter in sandwiches or smear it on apple slices. This makes a tasty snack that is full of nutritional benefits to help round out their diet.