Do you rarely think about your blood sugar levels unless they dip and you start feeling shaky and sweaty? If so, you’re not alone. However, these days it’s becoming trendy to monitor blood sugar levels around the clock—and not just for people who have diabetes. In this post I’ll cover the basics about how the food you eat impacts your blood sugar. We’ll also look at other factors that may influence your blood sugar levels, and if it makes sense to invest in a continuous glucose monitor.
Blood Sugar 101
Blood sugar, also known as blood glucose, is the body’s main source of energy. When we eat carbohydrate-containing foods, like fruit, dairy products, vegetables, grains, and foods with added sugars, the body breaks them down into smaller and smaller pieces as they travel through the digestive system. During this process, glucose from the food passes from the intestines into the bloodstream. It then circulates in the blood until the pancreas releases insulin to help move the glucose into the body’s cells. From there it’s used for energy or stored as glycogen in the muscles or liver for later use. If we have more glucose than we need and the storage sites are full, the excess is stored as fat.
Our bodies typically keep our blood sugar levels stable. Everyone experiences a normal rise in blood glucose immediately after eating, but it gradually goes back down as insulin does its job. Sometimes things go awry, however. For example, most of us experience symptoms of hypoglycemia (low blood glucose) when we don’t eat regularly. Rebound or reactive hypoglycemia occurs when we eat a meal or snack packed with simple sugars or refined carbohydrates. Our bodies try to “catch up” with that big sugar rush by releasing a bit too much insulin. And this causes blood sugar levels to dip below normal before coming back up.
People with diabetes either don’t produce enough insulin or their cells don’t respond well to insulin (known as insulin resistance). In both cases, hyperglycemia is the result: glucose stays in the blood instead of moving into the cells or storage. Over time, high blood glucose levels can damage blood vessels and nerves. And this can lead to an increased risk of kidney disease, eye disease, and cardiovascular disease.
Food Choices that Help You Balance Blood Sugar
What you eat, how much you eat, and when you eat all impact your blood sugar levels. The goal is to help the body avoid huge spikes and dips in blood sugar levels. Choosing nutritious food (and engaging in regular physical activity) helps keep blood sugar levels in normal ranges. Healthy food choices are also crucial for diabetes management.
The basics of a healthy diet don’t really change. Eat lots of fruit, veggies, and whole grains, along with a good amount of lean and plant-based proteins. Choose low- and fat-free dairy and drink plenty of water, limit alcohol, and consume minimal added sugar. This general advice is likely not new to you. But many people don’t pay close attention to their food choices or their body’s responses to those choices. For example, when you eat a higher-carb meal, how do you feel afterwards? Do you feel better after eating a balanced meal? Can you think more clearly when you eat regularly and are well-hydrated?
Here are our suggestions for how to put together meals that support healthy blood sugar levels:
- Portion your plate to follow MyPlate or the American Diabetes Association’s (ADA) Plate method. In general, that means half the plate is non-starchy vegetables, a quarter is lean proteins, and a quarter is carbohydrate foods (such as grains, fruit, starchy carbs, etc.).
- Focus on whole foods as the basis for meals and snacks. (See the basics of a healthy diet above for good, general choices.)
- Pair high-carbohydrate foods with either protein or fat-containing foods to help blunt their effect on blood sugar. (Check our handy mini-meal chart for some easy combos.)
- Eat regularly—avoid skipping meals or letting long periods of time go by without nourishment.
- Use Guiding Stars in the store aisles to help you plan meals and snacks that fit into the ADA recommendations for healthy eating. We also have lots of Guiding Stars-earning recipes here.
What Else Can Influence My Blood Sugar?
Blood glucose levels are constantly fluctuating throughout the day in response to many different situations and conditions. Here are some factors (aside from food) that may increase or decrease your blood glucose:
Increase:
- Steroid medications (glucocorticoid medications) taken for anti-inflammatory properties (whether inhaled, injected, or via IV)
- Skipping doses or taking blood sugar-lowering medications incorrectly
- Being sick or having surgery, partly because of hormones that release in response to the stress of illness
- Various stressful situations can increase the release of epinephrine, a hormone that raises blood sugar to help provide energy for quick responses (think “fight or flight”)
Decrease:
- Exercise or physical activity lowers blood glucose for up to 24 hours, and increases insulin sensitivity, which means more glucose can move into your body’s cells for energy
- Drinking a lot of alcohol without any food
- Not being able to keep food down, or severe vomiting
- Bariatric surgery can result in frequent reactive hypoglycemia
Blood Sugar Monitors—Do You Need One?
Continuous glucose monitors (CGM) give detailed information about how blood glucose rises and falls throughout the day and night. The new technology of CGMs makes it easy for people with diabetes to get this important data—without having to prick their fingers for blood samples multiple times per day. Some systems also have an alarm to alert the wearer (or others) if blood sugar levels become too high or low. In short, they’re very helpful if you have diabetes. And they may even be useful for making dietary or medication adjustments if you’ve been diagnosed with prediabetes. But if not? Consider this: these systems are not inexpensive, and if you don’t have diabetes they likely won’t be covered by insurance. They also aren’t infallible—a recent small study found that CGMs overestimated glycemic response in a variety of situations.
Overall, the use of CGMs for general “wellness” hasn’t been studied enough to warrant the expense for most of us. However, if money is no object and you’re curious about how your favorite breakfast impacts your blood sugar, getting the information won’t hurt you. And some elite athletes use the data to help optimize nutrition plans and food timing to improve performance. But are you that focused on your food and fitness to wade through large amounts of data every day? After all, just because you have lots of information doesn’t mean you’ll do anything with it. And if you’re already healthy, most likely your CGM readouts will reflect that in normal blood sugar readings.
Our advice: there’s too little evidence that using a CGM benefits people without diabetes or other blood sugar-related conditions. Spend your wellness dollars elsewhere—like on healthy food and some fitness gear.