White Bread
White bread is a staple for many breakfasts and sandwiches, but it’s a sneaky culprit when it comes to spiking blood sugar. This is because white bread is made from refined flour, which has most of its fiber stripped away during processing. Without fiber to slow the absorption of glucose, your blood sugar can jump quickly after eating just a single slice. According to a 2024 study in the journal Nutrients, foods with a high glycemic index, like white bread, are linked to higher rates of type 2 diabetes. The American Diabetes Association also points out that white bread is digested fast, leading to rapid increases in blood glucose. Even if you think you’re eating healthy by grabbing a turkey sandwich, the bread itself may be working against your efforts. It’s easy to overlook just how quickly something as simple as toast can shift your metabolism out of balance.
Sweetened Breakfast Cereals
Many people start their day with a bowl of cereal, but most popular brands are loaded with added sugars. The Centers for Disease Control and Prevention (CDC) warns that sweetened cereals can cause blood sugar to spike dramatically, especially in children and teens. According to new data from a 2023 Harvard School of Public Health review, some cereals contain as much as 20 grams of sugar per serving—that’s more than five teaspoons! These sugars are absorbed quickly because they’re not balanced by much fiber or protein. Even cereals marketed as “healthy” or “whole grain” can have high sugar content, so it’s important to check the nutrition label. For people with insulin resistance or prediabetes, these sugary breakfasts can set them up for a day of fluctuating energy and cravings.
White Rice
White rice is a mainstay in many cuisines, but it’s another food that can send blood sugar soaring. Research published in the British Medical Journal in 2024 found that eating white rice regularly is associated with a higher risk of type 2 diabetes, especially in Asian populations where rice is a dietary staple. The reason is that white rice is quickly broken down into glucose, causing a sharp rise in blood sugar after meals. Unlike brown rice, white rice lacks the bran and germ, which provide fiber and important nutrients. This makes the carbohydrate content more concentrated and easier for the body to convert to sugar. Experts now recommend choosing brown rice or other whole grains to keep blood sugar levels more stable.
Sugary Drinks
Sodas, sweetened teas, and energy drinks are among the fastest ways to spike your blood sugar. A 2023 report from the World Health Organization (WHO) stated that even a single can of regular soda contains up to 39 grams of sugar—almost 10 teaspoons. Because these drinks are liquid, the sugars hit your bloodstream almost instantly, leading to a rapid surge in glucose levels. The American Heart Association has repeatedly highlighted the link between sugary beverage consumption and increased risk of metabolic diseases. Unlike solid foods, these calories don’t offer any sense of fullness, so it’s easy to drink more than you realize. Consuming sugary drinks frequently is now considered a major driver of the global rise in diabetes and obesity.
Potatoes (Especially French Fries)
Potatoes may seem wholesome, but they’re high in starch, which the body quickly converts into glucose. A 2024 meta-analysis published in Diabetes Care found that people who ate more potatoes, particularly in the form of French fries, had higher blood sugar levels and an increased risk of type 2 diabetes. French fries are especially problematic because deep frying adds fat and calories, compounding the unhealthy impact. Even baked potatoes, without the skin, have a high glycemic index and can cause sharp spikes in blood sugar. The combination of high starch and low fiber makes potatoes less ideal for blood sugar control. Nutritionists now advise pairing potatoes with fiber-rich vegetables or protein to help blunt their effect on blood sugar.
Stabilizing Food: Oats
Oats are one of the best foods for stabilizing blood sugar, thanks to their high content of soluble fiber called beta-glucan. According to a 2023 review in the journal Advances in Nutrition, eating oats can lower post-meal blood sugar spikes and improve insulin sensitivity. The fiber in oats slows down the digestion and absorption of carbohydrates, leading to a gradual rise in blood sugar instead of a sudden surge. Oats also contain important vitamins and minerals like magnesium, which plays a role in blood sugar regulation. Many studies have shown that people who eat oatmeal for breakfast have improved blood glucose control throughout the day. Choosing plain, unsweetened oats is key—flavored instant varieties often come with added sugars that can undo the benefits.
