Sugar is a simple carbohydrate that is in many of the foods you eat, including vegetables. Many foods go through a process during manufacturing that adds refined sugars for taste. Vegetables naturally contain different types of sugars that your body uses for fuel and health.
Glucose is a single sugar molecule that is found naturally in vegetables. Glucose is the staple of energy for both plants and animals. When you eat a vegetable, you are consuming its stored glucose sugars. A plant makes glucose during photosynthesis. Sunlight, carbon, hydrogen and oxygen from water and air combine to make glucose, which serves as energy as well as a structure for the make up of vegetables.
Sucrose may be more familiar to you as table sugar. Sucrose is made when a glucose and a fructose molecule combine together. It is derived from the refinement of a sugar beet. Sucrose also occurs as a natural sugar in many vegetables, such as peas, sweet potatoes and carrots.
Starch is a polysaccharide that occurs naturally in vegetables. Polysaccharides are long chains of glucose molecules. Starch is the method of glucose storage for plants. For example, a corn plant stores its glucose molecules as the kernels of corn that you enjoy on a warm summer day. The starch in plants is also nutritious for humans to eat, providing a healthy source of carbohydrates.
Dietary fiber is a naturally occurring carbohydrate found in many vegetables. In most vegetables, fiber is made of cellulose, a non digestible complex sugar. Your body's digestive system can break down cellulose using the bacteria of the digestive system, but cellulose does not get absorbed by the small intestine. Instead, cellulose is useful to your body to promote the health of your digestive tract. Cellulose fibers help keep your digestive system clean and running smoothly.