Hey, did you know that loading up on cake, pizza and ice cream every day might not be good for your health? Well, yeah, of course you did. Most of us understand that junk food is called that for a reason.

But did you know that some other foods — ones you probably wouldn’t label “junk” — can impact your overall wellbeing because they make your glucose spike?

Foods with rapidly digestible carbohydrates release a rush of glucose into your bloodstream after you eat them, and that can cause a spike in your glucose levels. Frequent glucose spikes can affect not only how you feel from day to day,¹ but are also associated with other long-term health consequences, like insulin resistance, Type 2 diabetes and heart disease.^{1, 2} (Read a more detailed breakdown of what’s happening during a glucose spike here.)  

You could spend your whole day reading about this phenomenon. Science has a lot to say about which foods make your glucose spike, and how much to take that into account as you decide what to eat and drink.

Treat this article as an introduction to a much deeper topic. Here are five examples of foods that can cause glucose spikes.

5 Foods that May Spike Glucose

1. Rice

White rice is a staple in diets around the world, but it’s also a very starchy carbohydrate and therefore can cause a big glucose spike.³ Brown rice, while often considered healthier due to its higher fiber content, can also deliver a sizable glucose wallop — depending on factors such as cook time, portion size and the presence of other macronutrients (think protein and fat) in the meal.³ And the same goes for rice crackers, which are sometimes viewed as a “lighter” vehicle for cheese, dips and spreads but have a high glycemic index (GI), meaning they can have a significant impact on glucose.⁴

2. Oat Milk

There are plenty of reasons people drink this popular dairy alternative, but its high carb content and high GI put it on our watchlist for glucose spikes. When it comes to non-dairy milk in general, opt for lower-sugar versions like unsweetened almond, coconut or soy. These all have a lower GI than oat milk and are considered glucose-friendly alternatives.

3. Bagels

A plain bagel isn’t a doughnut — so it’s got that going for it. But bagels and doughnuts are similar in one unfortunate way: They have a high glycemic load, meaning they can significantly raise your glucose levels after you eat them. Try reducing the portion size and pairing with a meal that contains protein and fat to lessen the impact on your glucose.⁵

4. Bananas

We want to be clear, here: The banana can be a wonderful, healthy fruit. We included it on this list to highlight that bananas and some of their friends in the fruit family, such as pineapples and melons, contain more sugar than fruits like berries, and so the risk of a glucose spike is greater. Try to balance bananas with fiber, protein and fats in your meals and snacks. You also can opt for slightly green or just-ripe bananas, which have a lower GI than overripe (think brown spots) varieties.

5. Mix-Ins and Condiments

Sometimes, the things we add to foods contain hidden sugars that can cause glucose spikes. Be mindful of dumping specialty creamers into your coffee, topping your salad with mounds of dried fruits and tangy dressing, or dousing your chicken breast with barbecue sauce.

How to Find Out the Impact of Glucose

As you can see from our list, two factors make some of these glucose-boosting foods extra-sneaky:

• They don’t all necessarily taste sweet.
• It can be tricky to know — again, besides the obvious, ultra-processed stuff that isn’t good for us — exactly what the impact is of the different foods and drinks you consume.

For these reasons and more, there’s growing interest in continuous glucose monitoring (CGM) systems, such as Abbott’s Lingo CGM for health and wellness and FreeStyle Libre for people living with diabetes.

Both use a biosensor, to measure your glucose levels in real time and a smartphone app to help interpret that information for you. If something you’re eating is making your glucose spike, you’ll see it.

That was one of the biggest eye-openers for Botumile “Abe” Ngoma, an educator in Houston, Texas, when he began using our FreeStyle Libre 2 to manage his Type 2 diabetes.

“Food-wise, it helped me a whole lot,” he said. “There was this high-fiber cereal that I used to eat, and I thought it was the safest thing. But I realized, no, it was making my sugar (glucose levels) shoot up.”

His CGM helped him understand which foods were causing him to spike, and how to adjust to that.

The fact is, you’re unique. The more personal insights you have on our own metabolism, the better you’ll be able to understand how diet affects you.

References:

¹Jarvis PRE, et al. Continuous glucose monitoring in a healthy population: understanding the post-prandial glycemic response in individuals without diabetes mellitus. Metabolism. 2023 Sep;146:155640.  https://pubmed.ncbi.nlm.nih.gov/37356796/

²O'Keefe JH, et al. Dietary strategies for improving post-prandial glucose, lipids, inflammation, and cardiovascular health. J Am Coll Cardiol. 2008 Jan 22;51(3):249-55.  https://pubmed.ncbi.nlm.nih.gov/18206731/

³Boers HM, et al. A systematic review of the influence of rice characteristics and processing methods on postprandial glycaemic and insulinaemic responses. Br J Nutr. 2015 Oct 14;114(7):1035-45. https://pubmed.ncbi.nlm.nih.gov/26310311/

⁴Brand-Miller JC, et al. Glycemic index, postprandial glycemia, and the shape of the curve in healthy subjects: analysis of a database of more than 1,000 foods. Am J Clin Nutr. 2009 Jan;89(1):97-105. https://pubmed.ncbi.nlm.nih.gov/19056599/

⁵Kim JS, et al. Effect of nutrient composition in a mixed meal on the postprandial glycemic response in healthy people: a preliminary study. Nutr Res Pract. 2019 Apr;13(2):126-133. https://pubmed.ncbi.nlm.nih.gov/30984356/