Your Insulin-to-Carbohydrate Ratio: What’s Yours?

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Whether you have type 2 or type 1 diabetes, it's crucial to establish a baseline 'insulin-to-carbohydrate ratio' if you take insulin. Some of us have the help of our healthcare teams for this, but far too many of us are left to figure it out on our own. With type 2 diabetes, doctors often dismiss this concept altogether and tell patients they must eat X amount of carbs and take X units of insulin every 3 to 4 hours. An 'ICR' gives you freedom and flexibility...and better blood sugars!

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Insulin-to-carbohydrate ratio (IRC)

Your insulin doses aren’t just based on the carbohydrates you eat, but carbs are the No. 1 factor raising your blood sugar. Your insulin-to-carbohydrate ratio is the number of carbohydrate grams that 1 unit of insulin can properly manage. In other words: how many units of insulin do you need for this meal so your post-meal blood sugar is in goal range? An ICR is stated as ‘1 unit per X grams of carbs.’ 15 g is the usual starting place for people with type 1 diabetes, and 10 g for type 2.

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Find out your normal

It’s easy to think, “Well, I’m normal, so 1 (unit):15 (g) or 1:10 is probably fine for me,” but it’s crucial to do the follow-up work to be sure your ratio works. Plenty of healthy people with diabetes need more or less insulin per meal. The insulin resistance of a person with type 2 varies greatly — for one person it could be 1:3 and an-other could be 1:12.

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Create your own ICR experiment

Choose a meal when your blood sugar is often in goal-range prior to eating. Eat any previous meal at least four hours earlier so those carbs and insulin don’t affect your results. Test your blood sugar before eating. Even if it’s high, you can continue with the ex-periment. Choose a simple meal, such as an apple with peanut butter or toast (versus something greasy, loaded with fat and carbs, etc.). Continued…

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Calculate your ICR

Using CalorieKing.com or the nutrition panel on your food items. For example, using a 1:15 ratio: two slices of gluten-free UDI’s whole grain bread has 24 g of carbs, minus 1 g of fiber. 23 g / 15 (my ratio) = 1.5 units of insulin. Then, take that dose of insulin. 2 hours after eating, check your blood sugar. Are you sky-high? You definitely need a ratio with a lower carb amount so you’ll be taking 1 unit of insulin to cover a smaller number of carbs, like 1:10…

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If your blood sugar is low at the two hour mark:

You can conclude that 1 unit of insulin for 15 g of carbs is actually too much, so you can increase the number of carbs. For example, a 1:20 ratio means I would take 1 unit for 20 g of carbs instead of 1.3 units for 20 g of carbs using the previous 1:15 ratio. In a nut-shell, the calculation is: X g of carbs you’re eating divided by your ratio’s number of carbs = X units of insulin.

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Of course, diabetes is never quite that simple

During your experiment, avoid adding extra variables like exer-cise. Once you have a mostly reliable ICR, you’ll be better pre-pared. Most cardio exercise, for example, calls for 15 to 30 g of carbs per hour depending on the intensity. You can cut your insulin dose back accordingly so those carbs aren’t soaked up by insulin, resulting in low blood sugar.

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Your ICR will also change for a meal you eat after exercise, especially with resistance training (e.g., weightlifting)

Personal trainer and author Christel Oerum of the blog Diabetes Strong says she generally reduces her bolus amount for any pre- and post-workout meals by up to 50 percent. Neglecting this crucial detail can you leave with a whopping severe low blood sugar...trust me, I’ve done it!

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What about breakfast?

Some people find they need a much ‘stronger’ ICR for their break-fast because of increased insulin resistance in the morning. So, while you may use a 1:15 ratio for lunch, snacks and dinner, you might need a 1:5 ratio at breakfast. There’s no right or wrong amount: it truly comes down to your individual needs. Everyone’s body is a little different.

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But what about the indulgent stuff?

Keep in mind that ICRs are just a starting point for heavy, indul-gent meals like lasagna, Chinese food, or cupcakes with butter-cream frosting where there is a ton of carbohydrates combined with a lot of fat. Continued…

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How fat affects your digestion

The fat severely slows down the digestion process, so your meal can take hours to digest and impact your blood sugar. Spreading out your insulin dose (which could be 4x the expected dose) over the course of several hours will be crucial. Test often, take notes, and try again.

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There are certainly some people who never bother with ICRs and diabetes math

They simply look at their plate and just guess. If you’re really good at that, cheers to you! But it’s still helpful to have, at some point, pinpointed a ballpark ICR so your guesses aren’t completely random. The more consistency of what and when you eat does make the whole game easier.