Around 45 to 65 percent of your daily calories should come from carbohydrates, recommends the Institute of Medicine, but notes the type of carbohydrates you choose make a difference in your energy level, your weight and your risk of chronic disease. Make the most of the carbohydrates in your diet by choosing low-calorie, low-fat carbs that are rich in fiber, vitamins and minerals.
To determine how many calories you need from carbohydrates, start with the total calories you need to eat each day to lose, gain or maintain your weight. Designate 45 to 65 percent of that number for foods high in carbs. If you need 2,000 calories per day, 900 to 1,300 of those calories-- 225 to 325 grams -- should come from carbohydrates, as 1 gram of carbohydrate has 4 calories. The Centers for Disease Control and Prevention recommends that you get most of your carbohydrates from whole grains, fruits and vegetables, which contain little or no sodium or fat. According to the CDC, a diet high in simple carbohydrates, such as refined sugar, increases your risk of diabetes and heart disease and promotes weight gain.
All carbohydrates consist of sugar molecules, which your body converts into glucose for energy. Simple carbohydrates include one or two sugar molecules. Your body breaks down simple carbohydrates quickly, which gives you a fast burst of energy but raises your blood sugar.Complex carbohydrates consist of three or more sugar molecules. Your body converts complex carbohydrates to glucose more slowly, so their energy is released gradually and your blood sugar stays stable. Simple carbohydrates include the sugars in fruits and dairy products, as well as the refined sugar in processed foods. Complex carbohydrates include the sugars and starches in vegetables, fruits, beans and whole-grain foods.
Foods made with simple carbohydrates may have more calories and fat than foods rich in complex carbohydrates. According to the U.S. Department of Agriculture, one medium croissant made with butter and refined white flour has 406 calories, 46 grams of carbohydrate, 21 grams of fat and 2 grams of fiber. One medium oat bran bagel has 268 calories, 56 grams of carbohydrates and 1 gram of fat and 4 grams of fiber. The bagel offers more energy in the form of carbohydrates and more nutritional benefits in its fiber content than the croissant, with fewer calories and less fat.
In addition to the 45 to 65 percent of your calories that come from carbohydrates, proteins should make up 10 to 35 percent of your daily calories, while fats should make up 20 to 35 percent, according to the IOM. Your age, sex, weight and activity level make a difference in how much of each nutrient you need within those guidelines. An active person under the age of 50 may need more energy in the form of carbohydrates than an older, more sedentary person.
If you don't have time to count carbohydrate grams or calories, use your plate as a visual guide. Cover over half of your plate with vegetables or fruits and whole-grain foods, and add a serving of protein that's about the size of the palm of your hand. Reserve a small portion of your daily calories for unsaturated vegetable oils, nuts or oily vegetables, such as avocado and olives.