Would it even be an article on healthy foods if we didn't mention avocado? This fiber and healthy fat-filled fruit bring a ton of vitamins, minerals and phytonutrients to your lunch. Eating avocado (and the nutrients found in this fruit) may be linked to better cholesterol, weight maintenance and even improved attention. Use mashed avocado as a spread on sandwiches, or as Carroll recommends, mix it with canned tuna instead of mayonnaise. Add it to salads, tacos, grain bowls, wraps or on top of your black bean soup or chili. And yes it's still healthy if you make it into guacamole!