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8 Sneaky Things That Affect Your Blood Sugar Levels

Whether you have diabetes and measure your blood sugar levels daily or are just concerned about maintaining healthy blood sugar levels, it’s important to be aware of these unexpected factors that can spike your normal blood sugar.

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Skipping breakfast

People who eat breakfast may be better able to resist fatty and high-calorie foods later in the day. One study, published in a 2015 issue of Public Health Nutrition, found that adults with type 2 diabetes who ate breakfast ate less later in the day. A morning meal—especially one that is rich in protein and healthy fat—seems to stabilize blood sugar levels throughout the day. A study of obese people with type 2 diabetes who took insulin, presented at the 2018 meeting of the Endocrine Society, found that eating more at breakfast (but not a higher number of daily calories overall) resulted in weight loss, improved blood sugar control, and decreased the need for insulin. Here are some other things that happen to your body when you skip breakfast.

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Artificial sweeteners

Artificial sweeteners do not raise your blood sugar if you have type 2 diabetes. However, if you do not yet have type 2 diabetes, it’s best to avoid them. Consuming low-calorie sweeteners could promote metabolic syndrome and actually increase the risk of prediabetes and type 2 diabetes, especially those who are obese, according to the Endocrine Society.  While experts  are by no means saying that sugary beverages are healthier—particularly for people with diabetes who need to avoid them at all costs—these findings do suggest that people who drink artificially sweetened beverages should do so in moderation as part of a healthy diet. Here’s what else happens when you cut artificial sweeteners from your diet.

Hands holding a bacon cheeseburger over plate of friesveryulissa/shutterstock

A high-fat meal

People with diabetes may worry about the carb contents of their meals, but research suggests that fat content can affect blood sugar too—and be one of the macronutrients that raises blood sugar. In a review of studies published in 2017 in the International Journal of Health Sciences, researchers found an association between fat intake, type 2 diabetes, and impaired glucose tolerance. Fat causes carbohydrates to be digested more slowly. So if a patient is on insulin the insulin might peak at the wrong time, earlier than the carbohydrates are being digested. There is also some evidence to suggest that the fat content of the meal increases insulin resistance so that more insulin is needed to main glucose control.

Mug of black coffeeDima Sobko/Shutterstock


While population-based studies seem to indicate that a java habit can lower the risk of developing type 2 diabetes in the long run, evidence suggests that for people who already have diabetes, caffeine can be tricky and one of the foods that raise blood sugar. “It’s very individual,” says Aaron Cypess, MD, PhD, an investigator at the National Institute of Diabetes and Digestive and Kidney Diseases at the National Institutes of Health. “I don’t want to say don’t drink caffeinated coffee, but I’ll have a patient who’s like, ‘You know my blood sugar was 120 in the morning, and then I had a cup of coffee, black, no sugar, nothing added, and drove to work, and now it’s 200.’” Some people’s blood sugar levels may be more sensitive to the effects of caffeine than others, he notes. Here’s how to make your coffee habit healthier.

Woman in bed blowing her noseStokkete/Shutterstock


Whether it’s a cold, flu, or even a urinary tract infection, your immune system releases special germ-fighting chemicals that can throw your blood sugar out of whack. That’s why it’s important to make a “sick day plan“—special eating and drinking guidelines to help keep your sugar levels more balanced—says Dr. Cypess.  Staying hydrated (with non-caffeinated, non-sugar beverages) is critical (here are some tips for drinking more water and staying hydrated). It flushes excess glucose out and helps every aspect of your body work better. People with diabetes patients should let their doctor know when they’re sick; they may recommend more frequent blood sugar testing or adjust your insulin dosage. Don’t make any changes without consulting a medical professional.

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Skimping on sleep

A good night’s rest may be just the medicine your doctor ordered—especially if you have diabetes or are worried about getting it. A study published in 2018 in the journal Acta Diabetologica reports that people with diabetes and prediabetes who have what’s known as “low sleep efficiency”–a measure of how much time in bed is spent sleeping–have poorer cognitive function than those with better sleep efficiency. Lack of sleep can raise cortisol levels which can cause insulin resistance and hyperglycemia.

Man lighting a cigarettePeryn22/Shutterstock

Smoking cigarettes

Obviously, a smoking habit isn’t healthy for anyone, but cigarettes are particularly dangerous for people with diabetes. Whether you have type 1 or type 2, smoking increases your odds of serious diabetes-related complications, such as heart and kidney disease, vision loss, nerve damage, and poor blood flow in the legs and feet that can lead to infections, ulcers, and possible amputation, according to the Centers for Disease Control and Prevention. Here’s everything you need to know about A1C.

Man looking into medicine cabinet, holding pill bottleBurlingham/Shutterstock

Certain drugs in your medicine cabinet

Common drugs, including corticosteroids (such as prednisone or hydrocortisone) that are used to control asthma, COPD, and rheumatological condition can raise blood sugar, as can statins to improve cholesterol levels, and diuretics to lower blood pressure. Even joint or spine injections with hydrocortisone can cause hyperglycemia. Many of these drugs are important for other conditions, so if you use them, you might need to track and control your blood sugar more closely.

Medically reviewed by Susan E. Spratt, MD, on September 02, 2019
Originally Published in Reader's Digest