Carbohydrates supply the body’s primary source of energy. The brain and red blood cells use only glucose, the building block of carbohydrates. The American Diabetes Association recommends determining your patient’s protein requirements, using the recommended dietary allowance of 0.8 g/kg of body weight for adults, before determining the desired amount of carbohydrates and fat. Also, use your patient’s treatment goals, habits, and blood glucose and lipid goals as guides.When your patient chooses which carbohydrates to consume, instruct her to focus on the glycemic value of a carbohydrate rather than on the type of carbohydrate, such as simple or complex. The glycemic index, created in 1981, provides average glycemic values of certain foods. It can help you predict the rise in blood glucose after your patient has eaten certain carbohydrates. Foods that raise blood glucose levels quickly have a high glycemic value. These include white bread, some cereals, glucose, and root vegetables, such as carrots and potatoes. Foods with a low glycemic value include nuts, legumes, dairy products, fructose, and raw fruits.

Advise your patient to use the index as a guide and to monitor her blood glucose levels after she eats certain foods. Make it clear, however, that the glycemic value of a food is not equivalent to its nutritional value. Although sucrose has a lower glycemic value than a potato, for example, it provides far less nutritional value. And inform your patient that the glycemic value of a food can rise or fall depending on many factors, including the ripeness of the food, the preparation of the food, and the other foods eaten at the same meal.

If your patient is using regular insulin, she can count grams of carbohydrates to help her make food choices. Instruct her to count the total number of grams of carbohydrate in a meal she’s planning to eat. She should then compare that number to the amount of carbohydrate recommended for that particular meal in her meal plan. If she’s consuming more than is recommended, she can increase her regular insulin dose by 1 unit for every additional 10 grams of carbohydrate. If she’s consuming fewer carbohydrates than is recommended, she can decrease her insulin by 1 unit for every 10 grams less.

Instruct your patient to count grams of carbohydrates by consulting food labels, exchange lists, and carbohydrate-counting books. Counting grams of carbohydrate allows for more accurate insulin dosing and more flexible meal scheduling. It also reduces the number of hypoglycemic and hyperglycemic episodes.