Fat is an essential part of any diet, it's critical for the health of our cells, and helps our body absorb other nutrients. Healthful, fatty foods that are a great addition to any diet include oatmeal, eggs, chia seeds, and tofu. Visit Business Insider's homepage for more stories. Fat in food has gotten an unfair reputation as a belly-bulging demon that can wreck your diet and cause you to gain weight. But the truth is, we need some fat in our diets to survive. The proper amount of the right kind of fat can fuel your body and help feed your brain.