Carb Counting: Why and How

To maintain good blood sugar levels, people with diabetes can learn and use carbohydrate counting to plan their meals.

Why Count Carbs?

After you eat food that contains carbohydrate, it breaks down into glucose and enters the bloodstream. This is why your blood glucose, or blood sugar, rises after eating most sources of carbohydrate.

Carb counting helps to consistently control the amount of glucose going into the bloodstream at one meal. People with type 2 diabetes who don’t take rapid-acting insulin before meals can use what’s called basic carb counting. People with type 1 diabetes and those with type 2 who take insulin before meals will likely want to learn to use what’s called advanced carb counting. However, everyone should start with the basics of carb counting no matter how long they've had diabetes or what their ultimate carb counting goal is.

What Foods Contain Carbs?

There are healthier sources of carbohydrate and less healthy sources. Foods that contain nutrient-dense carbs are an important part of healthy eating and should not be avoided completely. Carbs provide energy and nutrients you need.

The calories in these foods and food groups are mainly from carbohydrate. Some contain varying amounts of protein and fat.  

• Starches: bread, cereal, pasta, whole grains
• Starchy vegetables: potatoes, corn, legumes
• Fruit and fruit juice
• Nonstarchy vegetables: green beans, tomatoes, lettuce
• Milk, yogurt
• Sugary foods: regular soda, gumdrops
• Sweets: ice cream, chocolate candy

Basic Carb Counting

With basic carb counting, the goal is to eat similar amounts of carbohydrate at the same time each day. For example, if you eat 40 grams of carb for breakfast, you should eat that amount at breakfast every day. Keeping carbohydrate intake consistent helps keep blood sugar under control. This doesn't mean you have to eat the same thing at every meal every day. You can choose from many different foods that have similar amounts of carb.

How Much Carbohydrate Should I Eat?

Carbohydrate amounts vary for each person depending on factors such as height, weight, age, activity levels, blood glucose-lowering medications, and weight loss goals. There is no one-size-fits-all amount; however, some general guidelines to keep in mind are:

• 45 to 60 grams per meal for women

•  60 to 75 grams per meal for men

• 15 to 30 grams per snack*

(*This is if you want and/or need snacks. You don’t have to eat snacks just because you have diabetes.)

While these guidelines are helpful for determining the amount of carb to include in your meals, a dietitian or diabetes educator can help you develop an eating plan specific to your needs.

Find a Diabetes Educator in Your Area

Get more information about how many carbs are right for you.

Know the Nutrition Facts

The Nutrition Facts label on food packaging can help you count the amount of carbs in foods and beverages. Look for:

• Serving size

• Total carbohydrate (in grams)

Serving size is important because all of the values on the nutrition label are based on one serving, not the entire package. Multiply the number of servings you will eat by the total grams of carbohydrate, and you will know how much carbohydrate you're eating.

Don't worry about the sugars on the food label. Sugars on the Nutrition Facts account for all of the added sugars as well as naturally occurring sugars from foods like fruit and milk.

Portion Control

The best way to evaluate your portions is to measure your food with measuring cups or a food scale at least on occasion. If the serving size is 1 cup, measure 1 cup to be sure that's how much you're eating. If the portion you plan to eat is more or less than the serving size on the label, then you will need to figure out how many grams of carb you will actually consume. It's a good idea to measure or weigh your food when you can until you get a good sense of serving sizes. Then periodically measure to be sure your carb count is accurate.

Keep Records

For carb counting to be effective in blood sugar control, keep good glucose records and food diaries. After a while, you'll get a sense of how certain foods affect your blood sugar levels so you can anticipate and avoid highs and lows. There are many digital apps and logbooks on the market to help you track food, medications, and other factors that impact blood sugar, such as exercise.

Knowledge is key. Carb counting teaches you how the foods you eat affect your blood sugar. It can help you minimize your risk of complications and feel more positive and confident about your food choices.