Without enough carbohydrates, your body has to break down other nutrients, like proteins and fats, for energy instead of letting them do what they're supposed to do in the body. You can avoid this situation by making sure that anywhere from 45 to 65 percent of your daily calories come from carbs. A single gram of carbs contains 4 calories, so just multiply the grams of carbs in a food by 4 to figure out how many carb calories that food contains.
(You can see how many carbs are in the foods you eat by looking for the phrase Total carbohydrate on the food label. Under the total carbohydrates, you usually also see the amount of fiber and sugar, in grams, that the food contains. Both fiber and sugar are part of the total carbohydrate number.)An easier option is to keep track of the total grams of carbs you consume. If you take this approach, aim to eat between 225 and 325 grams (g) of carbs per day for an average 2,000-calorie intake. For fruits and veggies, you can skip the counts and just eat a lot of plants, especially the green, leafy kind.
The two categories of carbs are simple carbs and complex carbs. Simple carbs are sugars — not just table sugar but also the sugar found naturally in food, like fructose in fruit and lactose in milk. Complex carbs, also called starches, are long chains of sugars; they're found in foods like grains, rice, pasta, potatoes, and beans. Your body has to break down complex carbs into simple sugars for them to be absorbed from the digestive tract into the bloodstream. Focus on getting the majority of your carbohydrates as complex carbs.Plan on having carbohydrates in the form of grains, fruits, and vegetables at every meal. Maintaining good energy means keeping your body fueled with its preferred energy source (you guessed it: carbs!) all day long.