To successfully master the art of dosing insulin, it is often helpful to start with a scientific mindset. This applies if you are using an insulin pump or manual injections.
Meal boluses are ideally meant to cover the macronutrients in a meal, mainly carbohydrates. The dose needed to cover a meal depends on the amount of carbohydrate, but is also affected by large amounts of protein. If the meal contains very complex carbs and fat that slows digestion, you may need to add a second bolus after one or two hours.
Most people dose their meal boluses by either remembering how much insulin they need for a specific meal, or by assessing how many grams of carbohydrate are in the meal, and dividing that sum by their carb ratio. If your carb ratio is 10, that means you need 1 unit of insulin for 10 grams of carbohydrate.
- Minimize all other variables: meals, fast-acting insulin, exercise, recent low blood glucose, illness, menstrual period, etc.
- Choose a time to test when your starting BG is close to target (in the range of 90–150 mg/dL is reasonable)
- Eat a predictable, low-fat (10–15g fat) meal with a known number of carbohydrate grams or foods with discrete packaged amounts
- Use a “normal” meal bolus type
- Repeat with same meal 2–3 times to obtain a trend
1AACE/ACE (2015) | 2 ADA (2018) | 3 Medtronic | 4 Tandem