Carbohydrate Counting

ADVICE ON WHAT TO DO WHEN THE CARBOHYDRATE OF YOUR MEAL CHANGES

This is the current in thing, although some cynics may say that we are just re-learning old lessions! The principle is quite straightforward, changes in blood glucose after eating are largely the effect of the carbohydrate content of the meal, so it is sensible to understand the amount of carbs in the food. You can estimate the carbo content of food, most processed foods have the amount expressed as total carbohydrate and sugar content per serving. For home prepared food, get a feel of portion size to work out the content. Take-outs and restaurants are fairly difficult, especially Chinese and Indian food, which often have added sugar, glucose syrup/fruit juice.

So make an estimate of the quantity of carbohydrate, a slice of bread typically has 15 grams (g)of carbohydrate, therefore a sandwich has 30g, a small potato has between 10-15g, a typical serving of rice has 20g of carbohydrate.

Experience from the use of CSCII pump users has been borrowed to make an estimate the effect of changes in carbo intake on meal-time bolus insulin dose, you can do a simple fudge-factor calculation which works well, but will need to be adjusted in the light of your experience. Divide your total daily insulin dose by 50, and the product will correct the effect of 10g carbohydrate. As an estimate 2 units of insulin will correct each 10g of carbohydrate: for example, if you take 60 units per day in total, 1.2 units are needed to correct 10g carbohydrate. So if you increase the carbohydrate content by 40g, you are likely to need 6 units of insulin to cope with that on average.

However, another expert suggests a simpler plan, with a constant 2 unit increase in insulin per extra 15g carbohydrate.

The other way round is just as important, if the meal has less carbo in it than you would normally have at that meal, e.g. a salad instead of potato, estimate the change, and cut the dose down, rather than having to grab something latter to avoid a hypo.