Which foods can cause your glucose to spike?

We’ve all heard the stereotypes that certain food choices — cake, pizza, ice cream — can be off-limits when you’re watching your health. To be sure, those opinions don’t always tell the full story. Food isn’t inherently “good” or “bad,” and each person’s needs and goals are unique. But did you know that some foods — ones people don’t consider off-limits — can still influence your overall well-being because they make your glucose spike?

When you eat foods with rapidly digestible carbohydrates, you often experience a rush of glucose into your bloodstream, quickly increasing your glucose levels. This rapid increase and the decrease that follows is typically called a “spike,” and it’s followed by a “crash.”

One of the ways to measure a food’s ability to impact a person’s glucose levels is through the glycemic index (GI). People can respond differently to foods with similar GI values, but, in general, foods with a high glycemic index tend to have a significant impact on a person’s glucose.⁴

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.)  

You could spend your whole day exploring the research about it. Science has a lot to say about which foods make your glucose spike, and how much you should 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, when eaten on its own, can cause a big glucose spike.³ Brown rice, while often considered healthier due to its higher fiber content, can also deliver a sizable increase to glucose — depending on factors such as cook time, portion size and the presence of other nutrients (think protein, fiber and fat) in the meal.³

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). While rice is a versatile grain and pairs perfectly with nutrient-dense choices like steamed vegetables and high-quality proteins, try to manage the portion size — pair smaller portions with more generous servings of non-starchy vegetables, proteins and fats to minimize the impact on your glucose levels.

2. Oat Milk

There are plenty of reasons people drink this popular dairy alternative, but, given its naturally high carb content — plus often-present sweeteners and flavors — we put this high-GI beverage on our watchlist for potential glucose spikes.

When it comes to non-dairy milk in general, choose fortified, low-sugar versions such as unsweetened almond, coconut or soy milk. They are less likely to impact your glucose as dramatically as oat milk. Nut- and protein-based milks tend to have a lower GI and are considered glucose-friendly alternatives.

3. Bagels

Bagels have a high glycemic load, meaning they contain many grams of carbohydrates and can significantly raise your glucose levels after you eat them. You can consider reducing the portion size, pairing a bagel with protein and fat to lessen the impact on your glucose,⁵ or taking a 15-minute stroll after eating. Any of these can help you incorporate bagels into your food choices while mitigating glucose spikes.

4. Bananas

We want to be clear: bananas are a great source of energy and a nutrient-dense fruit. We included it on this list to highlight that bananas and some of their friends in the fruit family, such as pineapples and grapes, contain more natural sugars per serving than fruits like berries. So, when you consume them solo, the risk of a glucose spike is greater. Try to balance bananas by adding fiber, protein and fats to 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. When reaching for items like specialty creamers for your coffee, dried fruits and tangy dressing to top your salad or barbeque sauce to spice up your chicken, try to do so in moderation and with the knowledge that the condiments may affect your glucose levels.

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:

• Different from the stereotype, they don’t all necessarily taste sweet.
• It can be tricky to know the specific impact of the various foods and drinks you consume because it’s different for you than for someone else.

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 sensor 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 and can then make informed adjustments to fit your lifestyle and health goals.

The fact is, you’re unique. The more personal insights you have on your own metabolism, the better you’ll be able to understand how different foods affect your glucose.

References:

¹ Jarvis 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/

² O'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/

³ Boers 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/

⁴ Brand-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/

⁵ Kim 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/

This story was originally published on November 22, 2024.