Fat A long-term storage form for energy in humans. It is also one of the three main nutrients in food (besides carbohydrates and proteins). Foods high in fat include butter, oil, nuts, and some dairy products. Related Articles: An Overview of Intermittent FastingNigerian Cuisine and Diabetes10 Low-Carb Foods to Strengthen Your Immune SystemSushi and Diabetes7 Tips for Healthy Eating While Working from Home