My two year old son has type 1 diabetes and is in good control, but I want to know how long it takes for certain foods with carbs to start working. I know sugar alone or candy works right away, but when I give him rice or pasta, I can test him an hour later and he is still low. I’m kind of confused. Also how long does it take for milk to kick in? How many carbs should he have for each unit of insulin? We’ve been giving him 1 Unit for each serving (15 grams). Is this correct?

As a rule of thumb, carbohydrates usually impact blood sugars the fastest and the most. On average, carbohydrates affect blood sugars one hour after a meal and impact blood sugars 100% of the time. This also depends on the other foods combined with the carbs, namely protein and/or fat. The different fat contents of milks will affect post meal blood sugars differently. Skim milk and 1% milk will boost blood sugars more quickly than higher fat milks (2% or whole milk) because fat tends to slow the rise in blood sugars from the carbohydrate in milk.

Each person will have a unique insulin to carb ratio (the amount of insulin needed to cover 15 grams of carbohydrate) based on age, weight, height, etc. It’s best to work with your diabetes team to determine an appropriate ratio based on post-meal blood sugar rises.

JMS