How Many Carbs Should I Eat in a Day?

If you have diabetes and are confused by carb counting, here's an easy-to-understand explanation from a registered dietitian.

carb counting

Carbohydrates are one of three macronutrients in food that supply your body with energy. Once carbs are broken down into simple sugars and absorbed into your bloodstream, the hormone insulin attaches itself to the sugar and pulls it out of the blood and into body cells, where it is converted to energy.

Insulin also helps store sugar in your liver when you have too much in your blood and release sugar when you don’t have enough. When you have diabetes, you need to balance the amount of carbohydrates you eat with the amount of insulin your body needs to perform these tasks.

Your job, along with your dietitian or diabetes educator, is to find the exact number of carbs that will help you stay healthy in the long run and feel your best from day to day. The American Diabetes Association recommends starting with 45 to 60 g carbohydrate at each meal and 15 to 20 g for snacks. You may need more or less, depending on your weight, activity level, blood glucose goals, and the type of medication you take.

Your daily starting goal should be to get between 45 and 65% of your calories from carbs. So, for instance, if you eat 1,800 calories a day, that translates to approximately 200 g carbohydrate each day.  If you eat more or fewer calories, adjust your carb count accordingly. Keeping in mind that 1 g of carbohydrate contains 4 calories, here’s the math:

1,800 calories x .45 (percent of calories from carbs) = 810 calories
810 calories / 4 (number of calories in 1 g of carbs) = 202.5 g carbohydrate

Not all Carbs are Created Equal

You have to learn the number of carbs in individual foods in order to figure out how many carbs you are getting in each meal or snack. Starchy foods such as breads, pastas, pancakes, starchy vegetables like corn, peas, potatoes and winter squash, fruits, beans, milk, yogurt, and sugary foods such as candy, cookies, cakes and pastries are all high in carbs.

But not all carbs are equal.  Fiber in foods can help slow down the absorption of carbohydrates into your bloodstream, so the carbs in whole-grain foods, beans, and high-fiber veggies will be released into your bloodstream more slowly than the carbs in dairy products, highly milled or processed foods, and sweets.

To give you an idea of the carb content of various foods, each of the following foods, in the amounts given, contain approximately 15 g carbohydrate:

• Apple, small: 4 oz
• banana, extra small: 4 ounces
• beans (kidney, black, pinto, etc.): ½ cup
• bread: 1 slice
• cereal, cold unsweetened: 3/4 cup
• cereal, hot cooked: 1/2 cup
• milk, reduced-fat: 1 cup
• pasta or rice, cooked: 1/3 cup
• sweet potato: ½ cup
• tortilla, corn or flour: 1 (6-inch)

Check the Nutrition Facts labels on packaged foods for both the carbohydrate and fiber content per serving for that food. Some product labels, such as those on oatmeal, list both soluble and insoluble fiber content in that product. If this is the case, people who rely on insulin therapy may want to subtract the amount of insoluble fiber from the total carbohydrate count, to come up with a more accurate number of carbohydrates that are actually absorbed into the bloodstream, and balance their insulin accordingly. For most people, however, the difference is negligible. 

You may want to create a carb-counter for yourself by keeping a notebook filled with foods you like to eat and their carb counts. The National Nutrient Data Base is a comprehensive listing of foods (more than 1,500 alphabetized products) and their nutritional values (including number of carbs per serving) that can be found online at: Click on the food you are interested in and it will take you to a page with the nutritional breakdown.

The exact number varies from person to person; start with the same amount of carbs recommended for most people, see how you feel, then fine tune your meals and snacks until you come up with the carb count that feels right for you.

Updated on: September 7, 2017
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