Food provides energy and nutrients that are essential for human survival and health. There are five main food groups that should be included in a balanced diet: vegetables, fruits, proteins, grains, and dairy. Eating a variety of foods from each group daily provides different types of nutrients and helps prevent boredom. In addition to the main food groups, small amounts of unsaturated fats like olive oil and nuts are also important for a healthy diet as they can help reduce risk of heart disease.