All carbohydrate is converted into glucose. In someone without diabetes the glucose level in the blood would be matched by insulin produced by the pancreas as shown below.
Normal insulin release
In Type 1 diabetes the same principle applies but instead of the pancreas producing insulin, the carbohydrate is matched by insulin injections or an insulin pump. Most people follow twice daily or basal bolus insulin regimes as explained in the following section.
If you are taking two injections a day, knowing the amount of carbohydrate you are eating can help you balance it with your insulin so that your blood glucose levels stay under control. You should eat roughly the same amount of carbohydrate at similar times each day. For example, at your main meal try to fill about a third of your plate with starchy carbohydrate.
More carbohydrate than usual can cause blood glucose levels to go too high and less than usual can cause a hypo (low blood glucose levels).
Basal bolus insulin
If you are using a basal bolus insulin regime or pump you can be much more flexible in adjusting the timings of and the amount of insulin you take with the amount of carbohydrate you eat and drink. This can be done by ‘counting carbohydrates’ - see Carbohydrate counting.
If you prefer fixed times and doses of insulin, it may be better to follow the principles for the twice daily insulin regime.