Diabetes: Counting Carbs if You Use Insulin
Diabetes: Counting Carbs if You Use Insulin
How do you count carbohydrate grams in your diet?
count carbohydrate grams at a meal, you need to know how much carbohydrate is
in each type of food, whether it is a slice of bread, a bowl of lettuce, or a
tablespoon of salad dressing. Fortunately, nearly all packaged foods have
labels that tell you how much total carbohydrate is in a single serving.
And you can get carbohydrate guides from diabetes educators and the American
To calculate the carbohydrate in food that
is not packaged, you will need to know standard portions of
carbohydrate foods. Each
serving size or standard portion contains about 15 grams of
When you know the number of grams of carbohydrate in
a meal, you can figure out how many units of insulin to take based on your
personal insulin-to-carbohydrate ratio.
For example: Your doctor may recommend that you take 1 unit of rapid-acting
insulin for every 10 to 15 grams of carbohydrate you eat. So if your meal
contains 50 grams of carbohydrate, and if your doctor has decided you need 1
unit of insulin for every 10 grams of carbohydrate, you would need 5 units of
insulin to keep your post-meal blood sugar from rising above your target
Your insulin-to-carbohydrate ratio may change over time. In
some people it will differ from one meal to another. You might take 1 unit of
insulin for every 10 grams of carbohydrate for lunch but take 1 unit for every
15 grams at dinner. Keep the following in mind when counting carbohydrate
- Portion control is important. If a package says
it contains two servings and you eat the whole package, you need to double the
number of grams of carbohydrate listed for one serving.
- Protein, fat, and
fiber do not raise blood sugar very much. If you eat a
lot of these
nutrients in a meal, carbohydrate will convert to
glucose more slowly than it would with a meal containing a small amount of
protein, fat, and fiber.
- Exercise affects blood sugar, allowing you
to use less insulin than you would if you were not exercising. Keep in mind
that timing makes a difference. If you exercise within 1 hour of a meal, your
body may need less insulin for that meal than it would if you exercised 3 hours
after the meal.
By keeping track of what you eat and testing your blood
sugar after meals and exercise, you can learn to estimate the effect of
protein, fat, fiber, and exercise on the amount of insulin you need.
Count carbohydrate grams and eat a balanced diet by:
- Talking with a
registered dietitian. He or she can help you plan the
amount of carbohydrate to include in each meal and snack.
- Measuring your food portions. You won't always have to measure your food,
but it may be helpful when you are first learning what makes up a standard
- Counting either grams or servings of carbohydrate. A registered dietitian will help you
plan how much carbohydrate, including sweets, to have in each of your meals and
- Eating standard portions of
foods that contain protein. Foods that contain protein
(meat and cheese) are an important part of a balanced
- Limiting saturated fats. A balanced diet includes a limited
amount of healthy fat. Talk with a registered dietitian about how much fat you
need in your diet.
Other helpful suggestions
food labels for carbohydrate content. Be careful to consider the serving size
on the package.
- Check your blood sugar level. If you do this before
and 1 hour after a meal, you will be able to see how the food you eat affects
your blood sugar level.
- Record what you eat and your blood sugar
results in a food record (What is a PDF document?). At each regular visit with your
registered dietitian or
certified diabetes educator, or whenever you think
your meal plan needs adjusting, you can review your
- Get more help. The American Diabetes Association offers
booklets to help people learn how to count carbohydrate grams in their diet, to
measure and weigh food, and to read food labels. But you will still need to talk with a registered dietitian to
establish a plan that fits your needs.
Test Your Knowledge
I can eat only a certain amount of carbohydrate at one
sitting, or my blood sugar will be too high.
Calculate the carbohydrate content in the following
breakfast. Use the information in the "carbohydrate foods"
and "foods that contain protein" links to calculate the
carbohydrate. The breakfast includes 2 eggs, 1 cup of milk, 1 slice of toast,
and 2 teaspoons of margarine.
- 30 grams of carbohydrate
- 35 grams of carbohydrate
Continue to Where to go from here
Return to Diabetes: Counting Carbs if You Use Insulin
E. Gregory Thompson, MD - Internal Medicine
Rhonda O'Brien, MS, RD, CDE - Certified Diabetes Educator
October 24, 2012
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