10 Sneaky Foods That May Increase Your Blood Sugar
You know you should avoid processed foods and sugary treats if you're watching your blood sugar levels, but there are some surprising culprits you should also think twice about, too.
Pay attention to your blood sugar
Maintaining steady blood sugar levels and avoiding spikes (and dips) is important for good health. “When blood sugar spikes, it sends off a cascade of events that can damage health,” says registered dietitian Erin Palinski-Wade, author of 2 Day Diabetes Diet. In healthy people, the body releases the hormone insulin, which acts like a key that unlocks the body’s cells so they can take up glucose and avoid spikes.
Over time, some people develop insulin resistance, which means body cells ignore insulin and blood sugar levels rise (which is dangerous because blood sugar is toxic at high levels). Insulin resistance is caused by a combination of factors including genetics, excess weight, a sedentary lifestyle, certain medications, and long-term eating patterns. Insulin resistance can lead to prediabetes and eventually type 2 diabetes.
In general, limiting foods that tend to spike blood sugar is a good thing, but even more so if you have prediabetes or type 2 diabetes. There are some types of food that are known to raise blood sugar in people with insulin resistance, such as candy, pastries, and sugary beverages, like soda. However, the blood sugar response to specific foods can vary, so if you have type 2 and you usually test your blood sugar, checking before and after eating is the best way to determine if a specific type of food spikes your blood sugar.
However, here are some foods to keep in mind as possible culprits when it comes to higher blood sugar.
Getting your caffeine fix has actually been associated with a lower risk of type 2 diabetes. Research published in the journal Diabetologia, found that people who increased their coffee consumption by at least one cup daily saw their risk of type 2 diabetes decrease by 11 percent over a four-year period. So there’s nothing wrong with coffee—particularly if it’s black.
It’s all about what’s in the coffee that can create a blood sugar problem, says Palinski-Wade. “Adding sweeteners, creamers, and other flavorings can increase the amount of added sugar, causing a rise in blood sugar levels,” she says, adding that for some especially sensitive folks, high amounts of caffeine can also impact blood glucose. It’s best to monitor your blood sugar response after drinking coffee (even black) to know how it affects you.
This is a good general rule: “Eat carbs as close to the natural source—or as minimally processed—as possible,” says registered dietitian Martha McKittrick, owner of Martha McKittrick Nutrition in New York City. While oatmeal can have a beneficial effect on blood glucose levels, according to research in the journal Nutrients, instant oatmeal is much more processed, and the flavored varieties often contain loads of added sugar. “The more processed something is, the easier it is for the body to break it down and raise blood sugar,” she says. If you want this breakfast favorite, look for the kind that takes a while to soften—steel-cut oats, for example, are a better option. (Avoid these habits and other sneaky things that raise blood sugar levels.)
Let’s be clear: Brown rice, or any unprocessed grain, is better for your blood sugar than refined foods like white bread and pasta. So always opt for whole grains since their fiber makes them take longer to digest, mitigating a blood sugar rise. However, you also have to pay attention to the amount of carbohydrates you eat at one sitting, Palinski-Wade warns. “That plays the biggest role in blood sugar management,” she warns. That means a huge serving of whole grains can easily put you over your carb allotment for that meal. One cup of cooked brown rice, for instance, contains 51 grams of carbs on its own—that’s before you tally up other sources in your meal, like vegetables or beans. Palinski-Wade recommends sticking to 30-45 grams or less per meal. Even if it’s healthy rice, you’re better off limiting yourself to a half cup. (Here’s more on the brown rice vs. white rice debate.)
Wheat bread that’s isn’t a whole grain
Again, whole grains are better than refined or highly processed grains. But make sure that’s what you are actually choosing, rather than a product that seems like a whole grain—but really isn’t. With so many bread options on store shelves, it’s easy to become swayed by label claims—like brands labeled “wheat” or “made with whole grain.” “This is very different from 100 percent whole-grain foods,” says Palinski-Wade. Read the ingredients list and make sure that the first item listed is 100 percent whole grain, she says. (Learn about these 15 other things diabetes doctors do to keep their own blood sugar in check.)
When eating out, it’s all about the food choices that you make when it comes to impact on blood sugar. So if you can choose takeout food that has more veggies and whole grains, that’s better for your blood sugar. But you should know that when it’s salty (and maybe even greasy), it can also be overly sweet. “A combination of the high-fat content, sugar added to the sauce, and white rice is the likely reason why it can cause a blood sugar spike,” says McKittrick. That said, you can still get takeout—if you steer clear of dishes laden with too much salt, sugar, and fat.
“Organic” is more label lingo that people tend to believe means 100 percent healthy. “Organic snacks don’t always equate to healthier options. I’ve had clients consuming organic candy, which, although made with organic ingredients, is still candy that’s packed with added sugar,” Palinski-Wade says. (Watch for these 7 clear signs you could have high blood sugar.)
Yes, they are fruit, but many brands add sugar to the mix to reduce the berry’s natural tartness. In fact, one popular brand contains nearly 30 grams of total sugar (some of this is coming from the fruit itself) per quarter cup. Choose varieties with no added sugar (read the ingredients list) and eat a portion that’s in line with your goals. As the American Diabetes Association points out, two tablespoons of dried fruit contain 15 grams of carbohydrates.
This one is tricky. Meat contains mostly protein and fat and few carbohydrates, which are the main driver of elevated blood sugar. So meat likely won’t have as big of a short-term impact on blood sugar as some other foods. However, the saturated fat content of meat is thought to contribute to inflammation and insulin resistance, so in the long term it’s not thought to be great for blood sugar. People with prediabetes and type 2 diabetes are also at higher risk for strokes and heart attacks, and saturated fat intake can contribute to cardiovascular disease. “High-fat animal proteins provide a large amount of saturated fat, which may make it harder to manage blood sugar levels and contribute to insulin resistance,” says Palinski-Wade. Look for cuts of beef that are considered lean, like “loin” and “round” cuts. Opting for grass-fed, if it fits into your budget, may also offer a heart-healthier fat profile, she says. (Here are the best meats to eat and the ones to avoid.)
Whole wheat pizza
It may be a whole grain, but “the number of carbs in a typical slice can equal three to four slices of bread,” says McKittrick. Ordering thin crust is a good move because it saves carbs, but it still raises blood sugar, she says. Plus, tomato sauce is a sneaky source of sugar too.
Some types of dairy
While dairy—yogurt, milk, cheese—can offer important sources of calcium and vitamin D, healthy, middle-aged women who consumed the highest amounts of milk products were more likely to have insulin resistance than those who ate the least, according to a study in the Journal of Diabetes Research. Dairy may stimulate the production of insulin, thus lowering insulin sensitivity, the researchers suggest. What’s more, the saturated fat in higher-fat dairy may have a negative impact on cardiovascular health, Palinski-Wade says. She recommends consuming low-fat dairy with little to no added sugar. Other research has suggested that low-fat dairy consumption is associated with a lower risk of type 2 diabetes in postmenopausal women, but the research has been mixed. (Don’t ignore these 10 silent signs of diabetes.)
Pick the perfect pairing
Adding healthy fat to foods can slow the rate of digestion and slow your blood sugar response. McKittrick suggests a tablespoon of natural peanut butter on a slice of whole grain toast. Fiber acts in the same way. McKittrick likes adding ground flaxseed or chia seeds to yogurt and berry bowl. One caveat: Just as with carbs, fat portions matter, too. “Large amounts of fat added to a meal can actually cause blood sugar levels to stay elevated longer,” she says.
What if your blood sugar is up?
The good news is that there is a lot you can do to lower blood sugar even if it goes up after eating. One quick thing that works? Exercise. “The best thing you can do is move your body,” says Palinski-Wade. “Movement allows your body to quickly use excess sugar for energy, which can help lower blood sugar levels,” she says. Drink plenty of water (to avoid dehydration if you’re urinating a lot) and limit carbohydrates at your next meal, she says. Follow these 12 rules to keep your blood sugar levels steady.
- Erin Palinski-Wade, RD, CDE, author of 2 Day Diabetes Diet
- Diabetologia: "Changes in coffee intake and subsequent risk of type 2 diabetes: three large cohorts of US men and women"
- Martha McKittrick, RD, CDE, owner of Martha McKittrick Nutrition in New York City
- Nutrients: "The Metabolic Effects of Oats Intake in Patients with Type 2 Diabetes: A Systematic Review and Meta-Analysis"
- U.S. Department of Agriculture: "Rice, brown, long-grain, cooked (Includes foods for USDA's Food Distribution Program)"
- American Diabetes Association: "Fruit"
- American Heart Association: "Making the Healthy Cut: Fish, Poultry and Lean Meats"
- Journal of Diabetes Research: "Dairy Consumption and Insulin Resistance: The Role of Body Fat, Physical Activity, and Energy Intake"