Counting carbohydrates is a food plan that adjusts the insulin dose based on the amount of carbs your child plans to eat.
In this plan, the insulin dosage and carbohydrates are not always the same day to day. This plan is more flexible and is usually started after you are familiar with food choices and insulin.
Carbs affect your child's blood sugar more than any other kind of nutrient. Insulin works with carbs to supply energy for the body. The main goal is to balance insulin with the carbs your child eats all through the day.
First, you and your diabetes care provider need to figure out how much insulin your child needs to take in relation to the amount of carbohydrate your child plans to eat. There are 2 ways to figure this out:
Units per carb choice (exchange): Count carbs in portion sizes of 15 grams. This is called a "carb choice" or an exchange. Divide the number of grams of carbs in a food by 15 to figure out carb choices. For example, if a container of yogurt with fruit has 45 grams of carbs, it equals 3 carb choices.
Units of insulin are then adjusted at every meal to match the number of carb choices. To use this method, your provider needs to tell you how many units of insulin you need for each carb choice. For example, if your child needs 1 unit of insulin for every carb choice, then for 3 carb choices, he would need 3 units of insulin (1 x 3 = 3).
Units of insulin per carb choice multiplied by the number of carb choices equals units of insulin needed.
I/C ratio: Most people use an Insulin to Carbohydrate ratio (I/C ratio) to figure out how much insulin to use. If you use a ratio, you do not need to convert the number of carbs to carb choices. An example of an I/C ratio is 1 unit of insulin for every 10 grams of carbs eaten.
For example, if you plan to eat 60 grams of carbs and your I/C ratio is 1/10, then you would need 6 units of insulin (60 ÷ 10 = 6 units).
Your dietitian will help you figure out your I/C ratio.
Adjusting the insulin dose
Your child may need to change the dose based on planned exercise, illness, stress, or menstrual periods that affect blood sugar levels. For example, your child may need less insulin if the blood sugar level is low (below 70 mg/dl or 3.9 mmol/L) or more insulin if the blood sugar is too high (above 200 mg/dl or 11.1 mmol/L). Your dietitian and healthcare provider can show you how to figure out these adjustments.
Carbs are found in foods such as:
Non-starchy vegetables, meats, and fats contain very little or no carb. They have less of an effect on blood sugar levels. You should still pay attention to meats and fats.
Your child should eat little or no butter, milk based salad dressing, bacon, cream, sour cream, stick margarines and shortening. These contain saturated fats.
Your child should limit soft margarines, light mayonnaise, oil based salad dressing, nuts, seeds, olive, canola, peanut, flaxseed oil and oily fish. These are healthier fats, but should be eaten in moderation.
You can also use the booklet Choose Your Foods: Exchange Lists for Diabetes to check how many carb choices are in different items. The Complete Guide to Carb Counting 3rd edition gives more detailed information and more carbs to choose from. You can order these publications from http://www.shopdiabetes.org/Categories/8-Diabetes-Books.aspx or by calling the American Diabetic Association at 1-800-232-6455.
In general, your child should take insulin so that it starts working as the blood sugar starts to rise. Most carbs are absorbed as sugar into the blood about 10 minutes after eating. The peak in blood sugar from food is usually about 60 minutes after eating.
Sometimes insulin can be given after eating. (For example, toddlers who may not eat consistently, or children with blood sugar levels less than 70 mg/dl or less than 3.9 mmol/L.) Your child's doctor and dietitian will help you create a schedule for when to take insulin and when to eat.