What is a Glucose Spike?

The phrase “glucose spike” isn’t a familiar term for many, but the experience it describes likely is

A glucose spike is that brief surge of energy that swells in us—especially in kids—after eating candy, cookies, or other sugary treats.

In other words, a glucose spike is a temporary rise in blood sugar.

To have a glucose spike is both common and natural. For a person with diabetes, however, rapid changes in blood sugar can be harmful. For a person living with diabetes, glucose spikes can lead to:

  • Fatigue
  • Frequent urination
  • Blurred vision
  • Headaches

Because of this, it’s important for people living with diabetes to understand what causes a glucose spike and how they can manage its effects. 

Glucose and diabetes

Despite its bad reputation, sugar is actually a very important part of the human diet.

Sugars come in many different shapes and sizes, but during digestion, most of them are broken down into the most basic sugar form: glucose. 

Glucose is packed with energy that our body can use to fuel all of its basic functions.

When we eat, sugars from our food are converted into glucose which is then fed into the bloodstream. There, it is shuttled throughout the body.

Over time, the amount of sugar in the blood decreases as it is used and stored by cells. People living with diabetes, however, have difficulty regulating this process and may end up with very high glucose spikes (hyperglycemia). 

What causes a glucose spike?

Glucose spikes can occur for a number of reasons.

Common causes include missed insulin shots, lack of physical activity, and high sugar diets.

Importantly, it’s not just sugary foods that cause glucose levels to spike. Here are foods that often cause large glucose spikes:

  • Carbohydrates: These are starchy foods—such as bread, pasta, and potatoes—which are high in complex sugars
  • Fruits: Even though fruits have important vitamins, they also carry high amounts of sugar (often one called fructose)
  • Alcohol: Certain types of cocktails, beers, wine, and champagne contain sugar and carbohydrates


Everybody responds to foods in their own way, so it’s important to talk with a healthcare professional about what you should be paying attention to. 

Managing glucose spikes

Spikes in glucose are natural and necessary, but it’s important to take steps towards preventing too dramatic of a spike.

The most important step you can take is to talk with your doctor—everyone has their own unique circumstances that require a personal plan.

In general, these plans tend to involve a few common threads:

(1) Frequent glucose monitoring to learn what foods cause your spikes

(2) Finding recipes to substitute out sugars

(3) Regular exercise, and

(4) Drinking water after exercise and after starchy meals

There are many steps people with diabetes (and pre-diabetes) can take to manage their glucose levels, including the cultivation of a healthy microbiome.

Want to know more about nutrition and Type 2 diabetes? Here are a few helpful resources:

  • Suh, Sunghwan, and Jae Hyeon Kim. “Glycemic Variability: How Do We Measure It and Why Is It Important?.” Diabetes & metabolism journal vol. 39,4 (2015): 273-82. doi:10.4093/dmj.2015.39.4.273
  • Umpierrez, Guillermo E, and Boris P Kovatchev. “Glycemic Variability: How to Measure and Its Clinical Implication for Type 2 Diabetes.” The American journal of the medical sciences vol. 356,6 (2018): 518-527. doi:10.1016/j.amjms.2018.09.010



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