Diabetes Forecast

The Healthy Living Magazine

The Basics of Carb Counting

How the carbs you eat add up to blood glucose control

By Allison Tsai , ,
various numbers superimposed over yellow plate

Andrey Kuzmin/Thinkstock

People without diabetes may glance at their dinner and see salmon, a salad, or a bowl of soup, but those with diabetes are faced with numbers—specifically, carbohydrate grams. If you're new to diabetes, you may wonder why you need to carb count at all. Read on to find out why carb counting is an important thing you can do to ensure blood glucose control, how to determine your carb needs, and which carb counting method is best for you.

Why Do Carbs Matter?

Carbohydrates are naturally found in certain foods. Grains, sweets, starches, legumes and dairy all contain carbs in varying amounts. (More on carb containing foods here.)

When foods and drinks with carbohydrate are digested, the carbs break down into glucose to fuel our cells, and the body's blood glucose level rises. In people without diabetes, blood glucose levels rise after eating but the body's insulin response keeps levels from rising too high. "[The] pancreas will release a squirt of insulin to help facilitate getting the glucose from your bloodstream into your cells, where it can be used as fuel," says Alison Evert, MS, RD, CDE, coordinator of diabetes education programs at the University of Washington Medical Center and a dietitian and diabetes educator at the Endocrine and Diabetes Care Center there.

If you have diabetes, the process doesn't work as designed. How carb counting can help your blood glucose control depends on your treatment regimen and whether or not your body makes insulin.

  • Type 1: If you have type 1 diabetes, your pancreas no longer makes insulin, so you need to take background insulin as well as offset the carbohydrate in your food with mealtime insulin doses. To do this, you have to know exactly how many carbohydrate grams are in your meal—cue carb counting.
  • Type 2: Because people with type 2 diabetes are resistant to insulin and may have a diminished supply, they need to moderate their carbohydrate intake and eat a consistent amount at each meal throughout the day—instead of all at one sitting. People taking oral medications may use a more basic form of carb counting than those on insulin.

How Do You Carb Count?

The best carb counting method for you is the one that addresses your medication and lifestyle needs.

If you take mealtime insulin, that means first accounting for each carbohydrate gram you eat and dosing mealtime insulin based on that count using what's known as an insulin-to-carb ratio.

"People who take rapid-acting insulin—type 1 or type 2—at or just prior to food intake need to match the amount of carbohydrate in their meal to achieve glucose control," says Hope Warshaw, MMSc, RD, CDE, author of Eat Out, Eat Well: The Guide to Eating Healthy in Any Restaurant. This advanced form of carb counting is recommended for people on intensive insulin therapy by shots or pump, such as those with type 1 and some people with type 2.

People with type 2 diabetes who don't take mealtime insulin may not need detailed carb counting to keep their blood glucose in line. Some do basic carbohydrate counting based on "carbohydrate choices." One choice contains about 15 grams of carb. Others use what's called the "plate method" to eat a reasonable portion of carbohydrate-containing foods at each meal by limiting grains and starchy vegetables to a quarter of the plate. Others still stick with traditional carb counting, too.

Which method is best for those with type 2? "There is no evidence that any of those methods works better than others to help the person achieve good blood glucose control," says Patti Urbanski, MEd, RD, LD, CDE, a diabetes educator with St. Luke's Hospital in Duluth, Minnesota.

The longer you practice carb counting, the more you'll remember the carb content of the foods you commonly eat, but it helps to reference nutrition labels, apps, books, and other sources that provide information about the carb content of specific food items.

How Many Carbs Should I Eat?

As for the ideal number of carbs per meal, there's no magic number. "How much carbohydrate each person needs is in large part determined by their body size and [his or her] activity level," says Urbanski. Appetite and hunger also play a role.

In order to figure out how many carbs you should be eating, schedule an appointment with your dietitian or diabetes educator to work out an eating plan specifically for you. This service, when provided by a dietitian, is known as medical nutrition therapy. Diabetes self-management education sessions also may include creating an eating plan.

During the sessions, you'll determine your carb needs and how to divide your carbs among your meals and, if desired, snacks. "Everybody's insulin response is going to be different, and we don't want to make the diet more restrictive than it needs to be," Evert says.

That said, if you haven't figured out your individual plan yet, the general guideline for most adults with diabetes is 45 to 60 grams of carbohydrate per meal, which is three to four carbohydrate choices. A snack would be around 15 to 30 grams of carbs, or one to two choices. That's just a starting point, however. Your total carb allowance should meet your energy needs, blood glucose targets, and weight management goals.

What Should I Eat?

Whether you count each carb gram or use one of the other meal planning methods, you'll want to choose foods that are rich in nutrients. "The quality of carbs is an important aspect," says Evert. Opt for foods that are unprocessed and in their natural state, such as whole grains, vegetables, and fruit that hasn't been broken down into smoothies or canned in syrup.

"I encourage people to eat their carbs instead of drinking them," says Evert. "That will be a lot more satisfying." Try to eat more whole foods, such as fresh fruits and vegetables, which are minimally processed and free from additives and artificial substances. Processed foods, such as packaged cookies, crackers and canned fruit, usually contain added salt, sugar, carbohydrates, fat, or preservatives. Eating more whole foods and less processed foods will also make your body work harder to digest them, which is a good thing for weight management.

If you eat mostly whole foods, and limit highly processed foods—whether that's swapping a doughnut for a bowl of fruit and yogurt for breakfast or switching from white to whole grain bread—you'll get plenty of nutrients, including vitamins, minerals, and fiber. As a bonus, you can indulge in a dessert from time to time, Urbanski says, "as long as you're thinking about the amount of carbohydrates in it and recognizing that you're not getting a lot of good nutrition in return for those grams of carbohydrates."

It can be hard to change your eating habits overnight, so start by making small changes and sticking to them. Just knowing which foods are better choices is a step in the right direction.

Get more great tips on carb counting!

Find out which foods contain carbs.

5 helpful tips for estimating portion sizes.

Our top carb-counting strategies.


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