Carbohydrates are macronutrients that provide energy for your body. Learn about the different types of carbs (fiber, starch and sugar), how they affect blood sugar and how much you need. Carbohydrates are a vast group of naturally occurring organic compounds. They are primarily produced by plants and form a significant portion of our food. The term "carbohydrate" literally means "hydrates of carbon," as their general formula was initially thought to be. Carbohydrates are organic molecules made of carbon, hydrogen, and oxygen that serve as a major source of energy in living organisms. They include sugars, starches, and fibers and are classified into monosaccharides, disaccharides, oligosaccharides, and polysaccharides. Carbohydrates are a large group of organic compounds consisting of carbon, hydrogen, and oxygen. Monosaccharides, Disaccharides, Polysaccharides.