While the chemical structures of naturally–occurring sugars and added sugars are identical, there is an important difference. According to the Guidelines, whole foods that naturally contain sugars also naturally contain vitamins, minerals, fiber, water, and other essential nutrients — all of which contribute to "diluting" the concentration of sugar in the food. These foods and beverages include vegetables, fruits, whole grains, dairy products, beans, peas, nuts, and seeds that are prepared without added sugars, starches, solid fats, and sodium. These foods are high in nutrients (nutrient–dense) and low in calories. Foods and beverages that contain excessive amounts of added sugar, on the other hand, are not as nutritionally beneficial. Where there is added sugar, there are more calories but not more nutritional value. Items with added sugars are thus energy–dense and nutrient–poor — the overall calorie density of the food increases while the overall nutrient density decreases.