Our ancestors ate many whole foods that commonly fell from trees or grew from the ground. Today we eat a large number of foods that have lost through processing some of their natural constituents like fiber and vitamins. In 1990, the government reacted to people's growing concern over nutrition. The Nutrition Education and Labeling Act of 1990 required all food labels to list their ingredients in order of decreasing weight. Recently, the food pyramid we often see on the side of cereal boxes divides food into six basic groups.
Grains compromise the base while fruits and vegetables compromise the next tier.
The pyramid recommends six to eleven servings of grains, three to five servings of vegetables and two to four fruits per day. Carbohydrates are the nutrient from which all other nutrients are derived. The basic carbohydrate is glucose. It can be rearranged to form fructose or galactose. They contain the same number of carbon, hydrogen and oxygen atoms, but their three-dimensional structures differ.