Elevated glucose levels can have detrimental effects on your blood vessels. Continuous glucose monitors (CGMs) are offering valuable insights into the foods that trigger some of the most adverse blood sugar reactions.
Here are 10 foods that appear to cause significant spikes in blood sugar levels, as indicated by real-time data collected from a continuous glucose monitor application.
1. Grapes
What happens: Many fruits are high in sugar and will produce blood sugar spikes (although whole fruit is always better than juice). Grapes have 15g–20g of sugar per cup, and though they have a low glycemic index, many people find they raise glucose levels sharply.
How to Make it Healthier: Eat fewer grapes, pair them with fat or protein, or swap them for berries like strawberries, raspberries, or blackberries, which have around half the sugar.
2. Oatmeal
What happens: Heavily processed “instant” or rolled varieties break down more quickly, leading to a sharp blood sugar rise, and flavored varieties often contain added sweeteners.
How to Make it Healthier: Swap your morning bowl for a smoothie topped with hemp seeds, almond butter, chopped nuts, and chia. If you just can’t give up oatmeal, aim for steel-cut oats or groats, and pair with healthy fat and protein like walnuts, almond butter, and chia. Try swapping oatmeal for grain -free granolas or a warm chia pudding.
3. Sushi
What happens: The white rice under the fish is a processed starch that can cause a glucose rise in many people. Soy sauce also frequently contains sugar. Sushi (fish) is a protein, and by itself is unlikely to spike blood sugar.
How to Make it Healthier: Order sashimi with no rice, and don’t drown it in soy sauce. Or, try cauliflower rice sushi, which is starting to appear at restaurants and easy to make at home.
4. Acai Bowl
What happens: Acai berries are low in sugar (just 2g or 3g per 100g) and contain good antioxidants, but they have a slight bitter taste, so commercial bowls tend to mix in sweeter fruits like bananas or mangos, sweeteners like honey, or sweetened nut milks, shooting the sugar through the roof.
How to Make it Healthier: Mix your own bowl when you order or make it at home. Reduce the sweeteners, add low-sugar fruits like berries, lemon juice or coconut, and mix in unsweetened milk. Adding veggies like spinach, and healthy fats like chia or flaxseed helps too.
5. Pho and Ramen
What happens: The spike is most likely from the noodles, white rice or a sweet sauce. Noodles (even rice noodles) are a processed food made with refined grains that tends to spike many people.
How to Make it Healthier: Pick dishes without noodles, or swap in alternative pastas made with konjac root or vegetables (spinach noodles, zucchini noodles, or tofu noodles). Avoid any sugary sauces or glazes.
6. Fast Food Restaurants like Chik-Fil-A and McDonald’s
What happens: Most items on these menus are processed foods. Restaurants likely added sugars, refined carbohydrates with little fiber, and poor nutrient content, all of which can cause a rise in blood sugar.
How to Make it Healthier: Chose a salad with beef, chicken breast, or tofu and skip sugary dressings or croutons. I prefer a burrito bowl without rice.
7. Donut
What happens: Donuts are made with refined white flour, and usually contain added sugar, even without glaze or frosting (which is often basically pure sugar).
How to Make it Healthier: To make any baked good more glucose friendly, swap refined flour for a nut flour, like almond, and use natural sweeteners like allulose or monk fruit instead of sugar.
8. Pizza
What happens: Pizza crust is a refined flour dough and often includes sugar. The tomato sauce and even processed meats like pepperoni and sausage may also contain hidden sugars.
How to Make it Healthier: Look for cauliflower pizza crust. For toppings, stick with healthy veggies and unprocessed, clean proteins like pastured raised chicken, grass-fed, grass-finished beef or pork beef or pork, or tofu.
9. Pancakes
What happens: Pancake batter contains ultra-refined white flour and also typically contains sugar. Top it with maple syrup, and it’s a trifecta of glucose spiking.
How to Make it Healthier: Chose pancake mixes that are grain- and sugar-free. Better options are pancakes made with coconut flour, pecan flour, walnut flour, cassava flour (note: cassava does spike some people), tiger nut flour, and almond flour.
10. Cereal
What happens: Read the ingredients list - if sugar is one of the first ingredients, avoid it. Don’t be fooled by phrases like “whole grain”—cereals are processed foods that will likely raise blood sugar.
How to Make it Healthier: Keto-friendly cereals with alternative sweeteners that may lower the glucose response. Start with grain free granola and unsweetened cashew milk.
Key takeaway: Prioritize consuming protein as the initial part of your meal, as it can help mitigate the impact of carbohydrates, such as bread, pasta, or a sip of wine, on your blood sugar.