How Long Does It Take to Lower a Blood Sugar Spike?
A blood sugar spike may happen at some point in your weight loss journey, typically after eating carbs. Your body will respond to bring your glucose levels down to a normal range, but how long will it take?

Just as individuals can have different blood glucose reactions to eating the same food, your body’s ability to clear excess sugar out of the bloodstream varies depending whether you have diabetes, prediabetes, or no diabetes.
In general, to help lower blood sugar faster, you can increase physical activity and refrain from eating foods with refined carbohydrates. It’s also important to understand the long-term health implications of living with high blood sugar.
Why Blood Sugar Spikes
After eating, the digestive system breaks down carbohydrates into simple sugar molecules called glucose, which are absorbed into your bloodstream. Certain foods are digested more slowly than others and will cause a gradual increase in your blood sugar.
On the other hand, meals that are low in fiber, and high in refined carbs and sugars cause a rapid increase of sugar molecules in the bloodstream. This influx of glucose leads to a sugar spike (hyperglycemia).
High blood sugar levels prompt the pancreas to release insulin, a hormone that regulates blood glucose levels. Insulin clears glucose from the bloodstream and moves it into cells where some is used for energy. Excess glucose is stored in the liver, muscles and fat tissues as energy reserves.
<p class="pro-tip"><strong>Learn about </strong><a href="/blog/control-blood-sugar-spikes-after-meals">controlling blood sugar spikes after meals</a></p>
Which Foods Are Most Likely to Make Blood Sugar Spike?
Ultra-processed foods are very low in fiber and very high in sugars. Examples of ultra-processed foods include anything deep fried, white bread products, non-diet soft drinks, french fries, baked goods, and candy.
You should be extra cautious choosing beverages, because any type of liquid sugar will have the fastest impact on your blood glucose levels. It is very easy to disguise added sugars in liquid because the sugar completely dissolves, giving you no visual context for how much sweetening agent has been added.
<p class="pro-tip"><strong>Learn about </strong><a href="/blog/achieve-stable-blood-sugar-levels-with-these-everyday-foods">foods that stabilize blood sugar</a></p>
Non-Food Factors That Can Impact Blood Sugar
Chronic stress can increase blood sugar and contribute to higher than normal numbers.1 The same is true for:
- Illness
- Recovering from surgery
- Being dehydrated
- Certain medications
Steroid-based medications are known to increase blood sugar, even in people without diabetes.2 Diet and lifestyle changes may help lower blood sugar levels for people taking prescription steroids, but not in every case. If medications are responsible for driving up your blood glucose, you will need to create a unique care plan with your doctor.
<p class="pro-tip"><strong>Learn about </strong><a href="/blog/water-lower-blood-sugar">how drinking water affects blood sugar</a></p>
How Blood Sugar Spikes Can Impact Overall Health
Some people are less able to efficiently clear excess sugar from their bloodstream and need to be very careful with their diet and lifestyle choices.
One blood sugar spike should not have long-term implications for your health. However, continuously high levels of sugar in your blood will increase your risk of diabetes, heart disease, and unhealthy weight gain.
Chronic high blood sugar in people with diabetes can result in diabetic ketoacidosis, a life-threatening condition that presents with shortness of breath, fruity breath, nausea, vomiting, and fainting.3

How Long Does it Take for a Blood Sugar Spike to Go Down?
Blood sugar spikes can be accompanied by symptoms such as headache and ringing in your ears, which is called tinnitus, but many people don’t feel any symptoms at all.
The American Diabetes Association has found that people who suffer from diabetes and prediabetes take longer to bring high blood sugar levels back down to normal, compared to people without diabetes.4
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People Without Diabetes
If you do not have diabetes, your body’s insulin will naturally bring down your blood sugar. It is expected that most people will see their glucose levels return to normal within two hours after eating.3
Exercise can help bring down blood sugar faster, but it is normal for insulin to take two hours to complete its cycle and successfully move surplus sugar out of your bloodstream.
People With Prediabetes
Prediabetes is a condition marked by high blood sugar, but not levels high enough to be called diabetes. People with prediabetes have lost some ability to clear sugar out of the bloodstream, though in most cases blood sugar can be managed through lifestyle and diet modifications.
For individuals with prediabetes, how long it takes to bring down a blood sugar spike can vary widely based on:
- How much insulin their body is able to produce
- What kind of food they ate
- How much sugar they ate
- Muscle mass
Getting some exercise after eating, even a light stroll or some chores around the house, can help bring blood sugar down more quickly.
People With Type 2 Diabetes
People diagnosed with type 2 diabetes still have some insulin, but they’ve lost the ability to successfully clear extra sugar out of the bloodstream.3
Depending on the progression and severity of type 2 diabetes, insulin medication may be needed to help bring blood sugar down. Blood sugar spikes treated with fast-acting insulin can normalize blood glucose numbers within 15 minutes.
People With Type 1 Diabetes
People diagnosed with type 1 diabetes were born without the ability to produce their own insulin, and require insulin medication.
Many patients use an insulin pump which releases doses throughout the day to keep blood sugar stable. If blood sugar spikes after eating a meal, it may be necessary to take fast-acting insulin, which takes around 15 minutes to start working.
Anyone diagnosed with diabetes or prediabetes should follow the care plan provided by their doctor.
How to Track Blood Sugar Spikes
A continuous glucose monitor (CGM) is an easy way to monitor trends in your blood sugar levels. The CGM device is worn on your arm and transmits data from the sensor to the Signos smartphone app.
All this personalized data gives you a crystal clear picture of how different elements in your life are impacting your blood sugar and possibly contributing to spikes.
The other method of checking your blood sugar is using a fingerstick device. You prick the end of your finger and use a glucometer to assess the sugar content in your blood. In contrast to CGMs, fingerstick glucometers only provide point-in-time blood glucose data.
<p class="pro-tip"><strong>Learn more about </strong><a href="/blog/cgm-uses">using a CGM to improve weight loss, sleep & exercise</a></p>

Things You Can Do to Reduce Blood Sugar Spikes
Frequent blood sugar spikes can have unpleasant side effects including fatigue, hunger and moodiness. For people without diabetes, simple lifestyle changes are the best way to prevent blood sugar spikes from happening as often, and reap the benefits of stable blood sugar.
Get Moving
Physical activity can help lower blood sugar and resolve blood sugar spikes. Your muscles rely on glucose for fuel, so the more you use your muscles the more fuel they will burn.
Here is an example of a full-body workout you can complete in just ten minutes to help bring your blood sugar down. Doing exercises that incorporate both aerobic activity and strength training are the most efficient way to engage your muscles and lowering your blood sugar.
Be Proactive With Food Choices
Try to limit your intake of foods with a high glycemic index (such as ultra-processed foods). High-glycemic foods are low in fiber and high in sugar, making them very likely to rapidly increase blood sugar.
<p class="pro-tip"><strong>Learn more about </strong><a href="/blog/how-glycemic-index-and-glycemic-load-impacts-glucose">the glycemic index</a></p>
Including high-fiber foods in your meals will help slow down digestion and decrease the impact sugar has on your bloodstream.5 High-fiber foods include:
<p class="pro-tip"><strong>Learn about </strong><a href="/blog/high-fiber-low-carb-foods">the best high-fiber, low-carb foods for blood sugar</a></p>
Protein also helps to slow down digestion and should be included in snacks and meals.6 You can vary your protein sources by switching between animal-based or plant-based options.
<p class="pro-tip"><strong>Learn about </strong><a href="/blog/protein-for-weight-loss">why protein helps with weight loss</a></p>
Some artificial sweeteners have been linked to increased blood sugars. Sucralose, which goes by the brand name Splenda, has been shown to raise plasma blood glucose levels.7 Limit your intake of sucralose products as much as possible to decrease the risk of blood sugar spikes.
Studies have found that vinegar can have beneficial effects on blood sugar, so choosing a vinegar-based salad dressing over ranch (for example) may be helpful to avoid a spike.
Main Takeaways
Without a diagnosis of prediabetes or diabetes, it should take one to two hours for a blood sugar spike to come down. You can opt for a walk or a workout to accelerate the process.
A CGM device can provide you with personalized insight into what causes blood sugar spikes. This data can help you prevent future spikes and empower you to make diet and lifestyle choices that align with your blood sugar goals.
One high blood sugar reading should not have a significant impact on your overall health and weight loss goals. However, if your glucose levels are consistently trending upwards, you should connect with your doctor to discuss the risk of long-term implications.
<p class="pro-tip"><strong>Learn about </strong><a href="https://portal.signos.com/plan">getting started with Signos</a></p>
References
- Mifsud, S., Schembri, E. L., & Gruppetta, M. (2018). Stress-induced hyperglycaemia. British Journal of Hospital Medicine, 79(11), 634–639. https://doi.org/10.12968/hmed.2018.79.11.634
- Clore, J. N., & Thurby-Hay, L. (2009). Glucocorticoid-Induced Hyperglycemia. Endocrine Practice, 15(5), 469–474. https://doi.org/10.4158/ep08331.rar
- Hyperglycemia (High Blood Glucose) | ADA. (n.d.). American Diabetes Association. Retrieved July 2022, from https://www.diabetes.org/healthy-living/medication-treatments/blood-glucose-testing-and-control/hyperglycemia
- Association, A. D. (2001). Postprandial Blood Glucose. Diabetes Care, 24(4), 775–778. https://doi.org/10.2337/diacare.24.4.775
- Yu, K., Ke, M. Y., Li, W. H., Zhang, S. Q., & Fang, X. C. (2014). The impact of soluble dietary fibre on gastric emptying, postprandial blood glucose and insulin in patients with type 2 diabetes. Asia Pacific journal of clinical nutrition, 23(2), 210–218. https://doi.org/10.6133/apjcn.2014.23.2.01
- Campbell, A. P., & Rains, T. M. (2014). Dietary Protein Is Important in the Practical Management of Prediabetes and Type 2 Diabetes. The Journal of Nutrition, 145(1), 164S-169S. https://doi.org/10.3945/jn.114.194878
- Campbell, A. P., & Rains, T. M. (2014b). Dietary Protein Is Important in the Practical Management of Prediabetes and Type 2 Diabetes. The Journal of Nutrition, 145(1), 164S-169S. https://doi.org/10.3945/jn.114.194878