It is best to get most of these calories from complex carbohydrates (starches) and natural sugars. In addition to calories, complex carbohydrates provide vitamins, minerals, and fiber. To increase your intake of complex carbohydrates and healthy nutrients: 1  Eat fruits and vegetables.2  Eat whole-grain rice, breads, and cereals. 3  Eat legumes (beans, lentils, and dried peas).t is best to get most of these calories from complex carbohydrates (starches) and natural sugars. In addition to calories, complex carbohydrates provide vitamins, minerals, and fiber. To increase your intake of complex carbohydrates and healthy nutrients: 1  Eat fruits and vegetables.