Carbohydrate Counting

Foods contain three major types of nutrients: carbohydrates (carbs), proteins and fats. Carbohydrate foods most often come from plants, such as fruits, vegetables and grains. Carbohydrates are chains of sugar molecules; thus, they have the greatest effect on blood-sugar levels when these chains are digested (broken down).

Complex carbohydrates are longer chains of sugars. They are absorbed more slowly into the blood and cause a slower change in blood sugar than simple carbohydrates. 90-100% of the carbohydrate (CHO) eaten converts to sugar (glucose) within 15 minutes to 1.5 hours. Only 58% of the ingested protein, and less than 10% of fat, are converted into sugar within several hours after consumption.

Simple Carbohydrates:

  • Fruit juices
  • Jams, jellies 
  • Candy
  • Sugar, maple syrup, honey
  • Sweeteners in food: dextrose, high fructose, corn syrup
  • Kool-Aid
  • Cakes, pies, cookies, ice cream, pudding

Complex Carbohydrates

  • Whole grain breads, crackers
  • Rice
  • Pasta
  • Tortillas
  • Beans
  • Corn, peas, lima beans

Why Count Grams of Carbohydrate?

By knowing how much carbohydrate is eaten, blood sugar levels can be partially controlled. This technique is helpful even if insulin is not currently being taken. Just keeping the CHO intake consistent from meal to meal can help stabilize blood-sugar levels. Even though the amount of CHO eaten (portion size) is important for blood sugar control, eating too much CHO can lead to weight gain, especially if insulin is being taken. Eating a variety of low-calorie foods is important for good health and weight control.

Helpful Hints

The magic number is "15" for counting CHO because, 15 grams of CHO = one carbohydrate choice or serving.

  1. If the food label indicates 5g of fiber or more per serving, deduct this from the total CHO amount since fiber does not directly affect blood sugar values.
  2. If a snack includes 15g or more of CHO, more insulin may be needed (possibly 1/2 the amount normally taken). This depends on individual blood sugar values.
  3. Sweet alcoholic beverages may require additional insulin. Dry wine, light beer, etc. may be better choices than sweet wine. It is preferable to drink alcohol with food to avoid low blood sugars. Avoid alcohol during pregnancy!
  4. Glycemic Index for a food indicates how quickly/how much blood sugar increases after eating the food. Keep a record of food intake and blood sugar levels. This will help identify which foods are more likely to cause blood sugar levels to climb quickly. Other foods consumed, the fiber content, & method of cooking can also affect the glycemic index of a particular food.


Easy Steps to Carbohydrate Counting

  1. Identify which foods have carbohydrate:
    • Starches 
    • Fruit Juices 
    • Vegetables 
    • Milk/Yogurt 
    • Sweets

    2. Determine the portions of foods you plan to eat:
        For example, measure by volume (1 cup), weight (3 oz) or count (2 each).

    3. Determine the number of grams of CHO food you plan to eat: (food labels, carbohydrate counting books,                 exchange lists)

    4. Total the grams of CHO you plan to eat for each meal.



2 slices of bread (starch) 30
Ham, cheese (meat) 0
1 cup peach (fruit) 30
1 cup pasta (starch) 30 
1 cup low-fat milk (milk) 12




    5. Start with the CHO factor 15 or use a factor according to your weight.

    • Divide the total CHO grams at each meal by your factor. This is how much Regular/Humalog [fast-acting] insulin you will take before you eat. The factor is the number of grams of CHO one unit of Regular/Humalog insulin will cover.

    6. ALWAYS check your blood sugar before you eat.

    • If your pre-meal BS is over 150 mg/dl, consider 1 additional unit of Regular/Humalog for every 50 points over 150. 
    • If you are pregnant and your pre-meal BS is over 100 mg/dl, use the supplemental insulin sliding scale your physician or nurse gives you. You will probably need more insulin for elevated blood sugars.

    7. Give the appropriate amount of insulin for the grams of CHO you plan to eat at the meal plus/minus extra                insulin needed based on your blood sugar.

    8. Record your blood sugar value in your log prior to eating the next meal.

    9. Make any needed adjustments in the factor based upon this blood sugar. If your blood sugar is still too high,           you may need to reduce your factor by several points (more insulin). If your blood sugar is too low, you may           need to increase your factor by several points (less insulin).

Examples of Carbohydrate Counting (examples coincide with 1-9 above)

1. Total grams of CHO for each meal.

2. 102g CHO ÷ 15 [factor], you should take 6.8 units Regular/Humalog insulin.
    Even if you do not take insulin, being aware of how much CHO you eat at a meal can help control your blood           sugars.

3. For example, if your blood sugar is 200 mg/dl you may need 1 additional unit of fast-acting insulin to take care       of the pre-meal elevated blood sugar.

    If you are already pregnant, consult with your physician or nurse. You will probably need to add more insulin           according to a sliding scale designed for you!

4. Give 6.8 units Regular/Humalog insulin for the CHO you plan to eat + 1 unit for the high pre-meal BS. A total of     7.8 units.

5. Your BS before your next meal should range between 80-140 mg/dl.

If you are already pregnant, your pre-meal BS should be <95 and/or <120 mg/dl 1 hr after meals.

6. Your CHO factor may vary from meal to meal. You may need more insulin with breakfast.


Recommended References:
American Diabetes/American Dietetic Associations, 1995, Exchange Lists for Meal Planning
Holzmeister, Lea Ann, 1997, The Diabetes Carbohydrate and Fat Gram Guide.
Kraus, Barbara, 1995, Calories and Carbohydrates, 12th Ed.
Borushek, Allan, 1999. Gram Guide, The Doctor's Pocket Calorie, Fat & Carbohydrates Counter

*Specific Individual diets should be approved by your health care provider. This information is provided for educational purposes only and cannot be used to plan individual dietary programs.