If you do not have prediabetes or diabetes, you may not think about the amount of sugar (glucose) in your blood. But that doesn't mean that you don't experience spikes in your blood sugar levels or that those spikes aren't affecting your health.
"Regardless of whether you have diabetes, when your blood sugar isn't stable, it can affect how you feel, eat and function throughout the day," says UCLA Health senior dietitian Christine Goukasian, MS, RDN. "Over time, frequent blood glucose spikes can make weight loss difficult and contribute to metabolic changes that increase your risk for chronic diseases, including diabetes."
Here's what you need to know about keeping your blood sugar levels stable:
What spikes blood sugar?
Food, specifically carbohydrates ("carbs"), is the primary and most common cause of increased blood sugar. Here’s what happens when you eat carbs:
- Your body breaks down carbohydrates into glucose (sugar) during digestion.
- The glucose gets absorbed into your bloodstream and raises your blood glucose level.
- Your body responds by secreting insulin, a hormone that triggers glucose to move out of the bloodstream into cells, where it will be used as energy.
Complex carbohydrates, such as sweet potatoes and lentils, are digested slowly, keeping the increase in blood sugar gradual and steady. Simple carbohydrates, such as candy and white rice, are digested and absorbed rapidly, causing a sudden spike in glucose levels. That spike remains until insulin gets the glucose moving — which could take an hour or two.
Food isn't the only thing that can spike blood sugar levels. Stress, hormonal changes and a lack of physical activity can all play a role in how well your body handles glucose.
According to the Centers for Disease Control and Prevention (CDC), other surprising triggers that may cause blood sugar spikes in some people include:
- Coffee, even without sweetener
- Dehydration, which makes blood sugar more concentrated
- Skipping breakfast, which can lead to increased blood sugar after lunch and dinner
- Sunburn, which acts as a stressor that increases blood sugar
- Time of day, with blood sugar being harder to control later in the day
How can glucose spikes affect your health?
Your body uses glucose for mental and physical energy throughout the day. When your blood glucose level is consistent and glucose moves slowly and steadily through the bloodstream to the cells, your energy will feel stable and constant. If your blood glucose level is swinging from high to low and back again, those spikes will leave you with strong cravings and fatigue that may affect your food choices and motivation to exercise.
If you have frequent spikes, they may also affect your long-term health. Studies show that regular glucose spikes in people without diabetes can cause:
- Endothelial (blood vessel lining) dysfunction, which can lead to cardiovascular issues
- Inflammation, which increases your risk for several chronic diseases
- Oxidative stress, which can damage cells, proteins and your DNA
It has also been suggested that over time, regular blood sugar spikes may affect mental health, energy, mood and sleep.
What does a blood sugar spike feel like?
It's not always obvious when your blood sugar spikes, but there are signs to watch for. For an hour or two after an unbalanced meal heavy in simple carbohydrates, you may notice:
- Increased thirst
- Increased urination
- Headache
- Short-lived energy burst, followed by a "crash" that causes fogginess and fatigue
"If you aren't eating consistent meals throughout the day, that's also a good indication that you may be spiking your blood sugar," Goukasian says. "When you allow your blood sugar to get too low, it is more likely to spike when you eat again."
Physicians may recommend that people with prediabetes or diabetes wear a continuous glucose monitor, a glucose sensor placed on the skin. The monitor tracks when blood sugar spikes occur. However, there is no substantial data suggesting that continuous glucose monitoring has benefits for people without diabetes. Monitoring blood sugar that closely may cause anxiety about small spikes, which are natural after most meals.
If you experience the signs of a blood sugar spike often, talk to your primary care physician.
Tips for stabilizing blood sugar
Goukasian says the best strategy for stabilizing blood sugar is balancing your meals.
"Fiber and protein really help with stabilizing sugar levels," Goukasian says. "That's why we focus on balanced meals that include whole grains, lean protein, fruits and vegetables. A balanced meal leads to fewer spikes and reduced sugar cravings."
To create a balanced diet that stabilizes your blood glucose:
- Eat low glycemic foods: The glycemic index provides each food with a rating from 0 to 100, based on how quickly the bloodstream absorbs glucose from that food. The more quickly glucose gets absorbed, the higher the glycemic number.
- Follow the plate method: For each meal, fill half your plate with vegetables, a quarter of the plate with protein and the remaining space with whole grains.
- Go for a walk after your meal: Going for a short walk after a meal — even for five minutes — can help stabilize blood sugar levels.
- Keep it simple: Your meals don't have to be fancy. Find some healthy and balanced recipes and repeat them on a weekly basis.
- Pair carbohydrate snacks with protein: Combine protein with carbs to create a balanced and satisfying snack. Eat fruit with yogurt. Add peanut butter to your apple.
"The goal is not to avoid carbohydrates altogether," Goukasian says. "Carbs are not the enemy. It's about the type of carbs and about finding balance. It's also important to have balanced and consistent meals throughout the day — without skipping. If you need help understanding what foods to eat, a registered dietitian can help."
