An individual is considered healthy when their body systems work well together and they can overcome life's challenges. To maintain good health, proper nutrition is important. Teenagers need around 2,200 calories per day according to the food guide pyramid, which recommends a variety of foods. Good nutrition includes getting enough calories, minerals, vitamins, proteins, carbohydrates, and iron. Maintaining good health also requires sufficient rest, exercise, cleanliness, and regular medical and dental checkups.