The six classes of nutrients are carbohydrates, fats, proteins, vitamins, minerals, and water. Carbohydrates include sugars and starches, and provide energy. Proteins are made of amino acids and are used to build and repair tissues. Fats provide long-term energy storage and insulation. Fiber is important for digestive health. A diet high in saturated fats can increase risks of obesity, high cholesterol, and heart disease. Maintaining a balanced diet and calorie intake through nutrition and exercise can influence overall health and weight.