Final answer:
Insulin is not a form of carbohydrate found in the diet; it is a hormone that regulates blood sugar. Carbohydrates such as sugars, starch, and dietary fiber are essential for energy and digestive health.
Step-by-step explanation:
Among the options provided, insulin is not a form of carbohydrates found in the diet. Instead, insulin is a hormone produced by the pancreas that regulates blood sugar levels. Dietary carbohydrates include sugars, starches, and dietary fiber. Sugars, like glucose and fructose, are monosaccharides or simple sugars. Starch, found in grains and vegetables, and dietary fiber, found in plant foods, are both polysaccharides, which are complex carbohydrates.
Carbohydrates are vital for several biological functions, as they are the main source of energy for the body. One gram of carbohydrates provides 4 Calories of energy. Even though dietary fiber does not provide energy, it plays important roles in maintaining gastrointestinal health, controlling blood glucose and cholesterol levels, and preventing constipation.