I read forums about managing diabetes with insulin, and one common topic is how to bolus for coffee. Coffee drinking habits are different for everyone. Some people drink coffee just once a day, while others drink throughout the day. Some people drink their coffee black, while others add lots of cream and sugar.

Let’s talk about a few common scenarios.

Drinking Black Coffee

Black coffee doesn’t have anything added to it. It is 0 carbohydrates, so carb counting to determine insulin dose would make you think that you don’t need any insulin. However, some people bolus for coffee, even when they drink it black, because the caffeine causes their blood glucose to rise.

Mayo clinic is inconclusive about the effect of caffeine on blood glucose, saying that it can either raise or lower it. However, most diabetes articles say that it raises blood glucose, so at least that’s the common anecdotal experience.

I haven’t personally found that to be the case, but my blood glucose does tend to rise in the morning. This is called the “dawn phenomenon“. I usually overcome this issue by taking an insulin bolus as soon as I wake up in the morning, or I exercise.

How much to bolus for early morning rise or black coffee? That’s going to be very individual. I do the equivalent of enough insulin for 5-15 grams of carbs, depending on a number of factors.

Coffee with creamer or sugar

I sometimes enjoy my coffee with creamer. I count the carbs and then usually add a little extra because that usually works out best. Maybe my carb ratio is off or maybe it’s just the speed at which sugar in the creamer hits the blood stream… In any case, I count carbs and then I bolus the insulin based on the carb count and other factors like my current blood glucose trend.

Getting the timing of the insulin bolus right takes practice. If you can figure out how early to pre-bolus for your coffee, you can lesson any spike from the coffee. The ideal pre-bolus time is individual. It could be anywhere between 5-30 minutes or longer.

Counting Carbs in Added Sugar

1 teaspoon of sugar is 5 grams of carbohydrates.

I’m not sure if all cubes of sugar are the same size, but according to Livestrong “One cube of sugar weighs 2.3 grams and has a total of approximately 9 calories.”

Use an App like Calorie King to look up coffee drinks

If you buy a pre-made coffee drink, try looking for nutrition facts on the company’s website, or searching a mobile app or search engine like Google for the exact drink. Depending on the amount of sugar, syrup, creamer, etc, the carbohydrate count can be quite high — or not. You may want to try sugar free creamer and sugar substitutes to reduce the carb count of your drink.

Related Links

• Healthline Diabetes Article: The Great Coffee Experiment and Blood Sugar Effect
• Diabetes Daily: Coffee and Blood Sugars: What’s the Connection?