A balanced diet contains a proper mix of carbohydrates, fat and protein. Together, they give you energy and the building blocks for growth, maintenance and activity, which is why you need to eat significant quantities of each every day.

There are two basic kinds of carbs: complex - which include pasta, rice, breads, cereals, fruits and vegetables - and simple, which include cookies, candy, soft drinks and pastries.

The big health difference: Complex carbs tend to be rich in vitamins, minerals and often fiber, too. Simple ones tend to be sugary and low in nutrients -- but high in calories.