Carbohydrate counting
an overview

What is a carbohydrate?
One of the three major energy sources, the one usually found in grains, fruits, milk and vegetables and the one most responsible for raising the blood glucose.

Why count carbohydrates?
Carbohydrate makes your blood glucose level go up. If you know how much carbohydrate you've eaten, you have a good idea what your blood glucose level is going to do. Carb counting can be used by anyone with diabetes - not just people using insulin. This method is also helpful for people who are using more aggressive methods of adjusting insulin to control their diabetes. The amount of meal and snack carb is adjusted based on the premeal blood sugar reading. Depending on the reading, more or less carb maybe eaten. Likewise, insulin may be adjusted based on what the person wants to eat. For example, if you want to eat a much larger meal, this approach can guide you to determine how much extra insulin to take.

Step 1: Know you meal plan.
Indicate on the chart below the number of servings from each group planned as part of your meal plan. The last row will be completed in Step 2.

Food Groups Breakfast Snack Lunch Snack Dinner Snack

Step 2: Know your carbs.
Most of the carbohydrate we eat comes from three food groups: starch, fruit and milk. Vegetables also contain some carbs, but food in the meat and fat groups contain very little carb. This list shows the average amount of carb in each food group per serving:

Starch : 15 Carb Grams Vegetable : 5 Carb Grams
Fruit : 15 Carb Grams Meat : 0 Carb Grams
Milk : 12 Carb Grams Fat : 0 Carb Grams

To make things easy, many people begin carb counting by counting the carb value of milk up to 15. In other works, one serving of starch, fruit or milk all contain 15 grams of carb or one carb serving. Three servings of vegetable also contain 15 grams. One or two servings of vegetables do not need to be counted. Each meal and snack will contain a total number of grams of carb.

Complete the following chart to test your understanding:
2 slices bread = ________ grams carb
1 whole banana (9" size) = ________ grams carb
1 cup oatmeal with 1 cup milk = ________ grams carb

Look back at your meal plan in Step 1. Total up the number of grams of carb for each meal and snack and write the totals in the last row. It is important to know your carb allowance for each meal and snack than it is to know your total for the day. The amount of carb eaten at each meal should remain consistent (unless you learn to adjust your insulin for a change in the amount of carb eaten).

Step 3: Using carb counting in meal planning

Here is an example to show how carb counting can make meal planning easier. Let's say your dinner meal plan contains 5 carb servings or 75 grams of garbs. (This is based on a meal plan of 3 starch servings, 4 protein, 1 vegetable, 1 fruit, 1 milk and 3 fat). The label on a frozen dinner of beef enchiladas says it contains 62 grams of carbohydrate. Instead of calculating how many exchanges that converts to, just figure out how man more grams of carb you need to meet your 75 gram total. Add about 15 more grams of carb (one serving of fruit or milk, for example) and you have almost matched your total.

Try another example. If you want to have chili for lunch, what else can you have with it. The label on the chili says it contains 29 grams of carbohydrate per 1 cup serving.

Where do you get carbohydrate information?
In order to count carbs, you must begin by knowing your meal plan and the average carb values of the food groups. Start by making sure you know the average amount of carb per serving in each food group. It is helpful to have a carb counting reference book.
The Nutrition Facts panel on the food label is the best way to get carbohydrate information.

What about protein and fat?
Protein and fat don't raise your blood glucose level as high as carbohydrate does. That's why you don't actually have to count them. But there are more calories in foods that contain fat than in most carbohydrate foods. Don't eat too much protein and fat or you may gain weight.

How do you count carbohydrate?
Carbohydrate is measured in grams (g). A gram is a unit of weight in the metric system. One ounce (oz) is about 30 grams (30 g). But don't confuse this with the gram weight of the food. A food may weigh 220 g but contain only 15 g of carbohydrate.

How do you know what size portions to eat?
Practice, practice, practice. Don't rely on measuring once and then just "quesstimating". Pull out the scales at least once a week to check yourself and reinforce your skills. Use a glass which you know only holds 4 or 8 ounces to better control your portion. Check your cereal portion using measuring cups. The cereal label will give you a more precise nutrition information such as calories, carb and fat grams that the food group averages. You have to weigh or measure your portions to know how much carbohydrate is in a serving. Before you can get to the point where you can just look at a portion of food and estimate the grams of carbohydrate in it, you have to practice weighing and measuring a lot of servings of individual food items. When you're used to seeing proper portion sizes, you'll be ready to count by looking.

How do you develop carbohydrate/insulin ration?

The amount of carbohydrate you eat determines how much insulin you need to cover a meal. Yours carbohydrate/insulin ration will cover your usual amount of protein and fat, as well as your carbohydrate in that meal. There are several approaches you can take to learning your individual carbohydrate/insulin rations. Two commonly used methods are Carbohydrate Gram Method and Carbohydrate Choices Method.

Carbohydrate Gram Method
The carbohydrate gram method allows you to see the difference in your ratios from one meal to another. For example, some people find their ratio at dinner is different from their ratio at breakfast. Many people have a lower carbohydrate -to-insulin ratio at breakfast than they ave at dinner. For example, at breakfast the ratio may be 10/1, while at dinner that ratio is 15/1. This means that at breakfast 1 unit insulin covers 10 gram of carbohydrate, while at dinner 1 unit covers 15 grams of carbohydrate. This happens when early morning hormones affect your sensitivity to insulin, causing high BG (often called "dawn phenomenon") and a greater need for insulin in the morning.

Please not that the lower the carbohydrate/insulin ratio, the more insulin you need to cover your food. Using the carbohydrate gram method to figure your carbohydrate/insulin ratio is simple if you have met certain criteria.

  • First, you should be eating a consistent amount of carbohydrate at the meal for which you want to find your ratio.
  • Second your insulin dose for that meal should have been fine-tuned so that your premeal and your post meal BG's are within your target range. For example your premeal target range maybe 3.8-8.3 mmol and your 1 1‹2 -2 hour post meal target plus or minus 2 points but less than 10 mmol.
  • Once you meet these criteria, select 3 days of records of the same meal when both your premeal BG and your BG by the next meal were in the target range.
    For the first day's meal, divide the number of grams of carbohydrate by the units of insulin (Regular or Humalog). For example, if you are looking at breakfast and you took 3 units of Humalog for 45 grams of carbohydrates, you carbohydrate/insulin ratio is

    45 grams carbohydrate = 15 grams carbohydrate
    3uR 1u
    This would be a 15/1 ratio.

    You may now want to experiment with the ratio you have calculated. Using the previous example, you might try eating a 60-gram carbohydrate breakfast.

  • Divide the total number of grams of carbohydrate by 15 to find the number of units you'll need.
    60g carbohydrate dived by 15 = 4 u R
    You would take 4 units for premeal BG in the target range.
  • Remember also to figure how much or less insulin you need whenever your BG is not in the target range (your insulin supplement).
    When you use a carbohydrate/insulin ratio, you first figure your dose based on the amount of carbohydrate that you plan to eat. Then you add or subtract the amount of insulin needed to bring your GB into the target range.

Carbohydrate Choices Method

If you do not count actual grams of carbohydrates but think instead in carbohydrate choices or exchanges, you may prefer the carbohydrate choice method which is :

1 carbohydrate choice = 15 grams carbohydrate

The ratio is found by dividing the number of units R or H by the number of carbohydrate choices that insulin dose covers.
If you eat a meal with 6 carbohydrate choices and take 6 units R for a BG in the target range, then your ratio would be 6uR divide 6 carbohydrate choices = 1 unit of insulin per carbohydrate choice.
If your insulin requirement is 9 units R for 6 carbohydrate choices, your ratio would be
9uR divide 6 carbohydrate choices = 1.5 units insulin per carbohydrate choice

Comparison of Carbohydrate Gram Method and Carbohydrate Choice Method

The carbohydrate gram method offers you more precise insulin adjustments for the grams of carbohydrate that you eat. Tp fine-tune your adjustments using this method, it is important to weight and measure foods and use food label information and carbohydrate reference books.
Estimating carbohydrate to be eaten based on the Exchange Lists or the carbohydrate choice method is simpler but not as accurate. See the example below.

Food Carbohydrate
Gram Method
Choices Method
1 lg baked potato
1/2 cup broccoli
1 small roll
3 oz pork tenderloin
1‹2 cup fruit cocktail
2 tsp margarine
5 choices or 75g

[One serving = 1 carbohydrate choice or 15 grams of carbohydrate]

Bagel 1/2
Bread (white, rye, whole-wheat) 1 slice
English Muffin 1/2
Hot Dog or Hamburger Bun 1/2
Roll (plain, small) 1
Pita (6" across) 1

Bran Cereal 1/2 cup
Cereals (cooked) 1/2 cup
Cereals (unsweetened, ready-to-eat) 3/4 cup
Flour (dry) 3 Tbsp
Oats 1/2 cup
Muesli 1/4 cup
Granola, low fat 1/4 cup
Grape-Nuts 1/4 cup
Pasta 1‹2 cup
Puffed Cereal 1 1/2 cups
Rice (brown or white) 1/3 cup
Shredded Wheat 1/2 cup
Sugar Frosted Cereal 1/2 cup

Bakes beans 1/3 cup
Corn 1/2 cup
Corn on Cob (medium) 1
Mixed vegetables with corn, peas or pasta 1 cup
Peas, green 1/2 cup
Potato, baked or boiled 1 small
Potato, mashed 1/2 cup
Squash, winter 1 cup


Melba Toast 4 slices
Popcorn (no added fat) 3 cups
Saltine Crackers 6
Rice Cakes, 4" across 2
Snack Chips, fat free (tortilla, potato) 15-20

Apple, unpeeled, small 1
Applesauce (unsweetened) 1/2 cup
Banana, small 1
Grapes 17
Kiwi 1
Orange, small 1
Peach 1
Pears, large, fresh 1/2
Raisins 2 Tbsp
Raspberries 1 cup
Strawberries 1 1/4 cup


Apple juice/cider 1/2 cup
Cranberry juice cocktail 1/3 cup
Fruit juice blends, 100% juice 1/3 cup
Grape juice 1/3 cup
Grapefruit juice 1/2 cup
Orange juice 1/2 cup
Pineapple juice 1/2 cup
Prune juice 1/3 cup

Skim milk 1 cup
1/2% milk 1 cup
1% milk 1 cup
2% milk 1 cup
Whole milk 1 cup
Plan nonfat yogurt 3/4 cup
Low fat, fruit flavored 1 cup

[1 1/2 cup cooked = 15 g carbohydrate
Asparagus, Beans (green, wax), Bean Sprouts, Beets, Broccoli, Brussel Sprouts, Cabbage, Carrots, Celery, Cauliflower, Cucumber, Eggplant, Green Onions, Mix Vegetables (without corn, peas, or past), Mushrooms, Onions, Peppers, Radishes, Salad Greens, Spinach, Summer Squash, Tomatoes, Tomato/vegetable juice, Turnips, Zucchini

[1 carb = 1 carbohydrate choice (or 15 g carbohydrate)
Angel food cake, unfrosted (1/12th cake) 2 carbs
Brownies, small 1 carb, 1 fat
Cake, unfrosted (2" square) 1 carb, 1 fat
Cake, frosted (2" square) 2 carb, 1 fat
Cookie or sandwich cookie (2 small) 1 carb, 1 fat
Cupcake, frosted (1 small) 2 carbs, 1 fat
Doughnut (plain, 1 medium) 1 1/2 carbs, 2 fat
Doughnut (glazed) 2 carbs, 2 fat
Fruit juice bars 1 carb
Fruit spreads, 100% fruit ( Tbsp) 1 carb
Granola bar (1) 1 carb, 1 fat
Granola bar, fat-free 2 carbs
Honey 1 Tbsp 1 carb
Ice-cream (1/2 cup) 1 carb, 2 fats
Ice-cream, light (1/2 cup) 1 carb, 1 fat
Ice-cream, fat-free, no sugar (1/2 cup) 1 carb
Jam or jelly, regular 1Tbsp 1 carb
Milk, chocolate, whole 1 cup 2 carbs, 1 fat
Pie, fruit, 2 crusts (1/6 pie) 3 carbs, 2 fat
Pie, pumpkin or custard (1/8 pie) 2 carbs, 2 fat
Potato chips (12-18) 1 carb, 2 fats
Salad dressing, fat free (1/4 cup) 1 carb
Sherbet, sorbet (1/2 cup) 2 carbs
Spaghetti or past sauce (1/2 cup) 2 carbs
Sugar (1 Tbsp) 1/2 carb