Starchy describes foods that contain a large proportion of starch, the storage carbohydrate of plants. Potatoes, rice, wheat, maize, cassava, yams, and foods made from them — bread, pasta, noodles — are the classic starchy foods. Starch is made of long chains of glucose, and the human body digests it into glucose for energy, which is why starchy foods are the world’s main calorie source. The texture of cooked starchy foods depends on gelatinisation: when heated in water, starch granules swell and thicken, giving body to sauces and a fluffy interior to a baked potato. Nutrition guidance generally treats unrefined starchy foods, with their fibre and micronutrients intact, as healthier choices than heavily refined ones.