Glucose is the primary source of energy for your body, fuelling all of its processes and functions. However, glucose also affects how the brain functions, body weight and your mood, and is crucial for people with diabetes.
The body functions at its best when glucose levels are stable. Therefore, it is important to avoid causing huge glucose spikes in order to feel your best. But not only will stable blood sugar help to maintain optimal physical and mental health, it will also help to prevent diseases that are a result of fluctuating glucose levels.
However, in order to stabilise your glucose levels, we need to understand what affects them in the first place, which is exactly what we will be taking a closer look at.
Things that affect blood glucose levels

1Types of Food
Eating high-carbohydrate foods, such as bread, cereals, pasta, starchy vegetables, and some fruits can raise your blood sugar. This is because these carbohydrates are broken down into glucose and released into the bloodstream. The more carbs, the more rapidly your blood glucose levels increase, especially with simple carbohydrates.
Studies have found, that pairing your carbohydrates with healthy fats or protein may help to prevent that big spike in blood glucose after eating. But healthy fats and protein are not the only things preventing spikes in blood sugar! Did you know that consuming vinegar before or with your meals (diluted in water) can give you similar benefits when it comes to preventing a blood glucose spike?
On top of that, the glycemic index (GI) can also tell you how much a certain food may affect your glucose levels. The glycemic index is an indicator of how quickly a certain food will be converted to glucose in the bloodstream. This means you want to focus on foods with a low glycemic index in order to avoid big spikes in glucose.
How to manage:
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Focus on more complex carbohydrates
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Pair carbohydrates with healthy fats and protein
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Eat food with a low glycemic index
2Meal Timing

The timing of your meals may also impact how well your body regulates glucose levels. Some studies have found that people tend to have higher blood sugar levels after eating in the evening than in the morning.
On top of that, eating regularly throughout the day can help to keep your blood sugar stable as opposed to spiking and crashing.
Now, does that mean you should be snacking constantly? Unfortunately, it’s not that simple. You see, snacking constantly might also contribute to high blood glucose levels.
According to Jason Fung, a Canadian nephrologist and author of several books, our bodies are constantly producing insulin to deal with the influx of glucose when we snack a lot. Instead, you should focus on eating larger and more satisfying meals that will keep you full for longer periods.
On top of that, intermittent fasting can also help you to improve insulin sensitivity and reduce blood glucose levels, according to Fung.
How to manage:
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Eat more in the morning and less in the evening
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Eat regularly throughout the day
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Focus on more satisfying meals as opposed to snacking a lot
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Try intermittent fasting
3Physical activity or lack of it
Exercise boosts your body’s sensitivity to insulin which helps counteract insulin resistance and maintain healthy blood glucose levels. This is partly due to the fact that your muscles use glucose as fuel when you work out, in turn lowering your blood sugar levels.
Physical inactivity and a sedentary lifestyle can contribute to high blood sugar levels and even the development of diabetes.
However, the timing and intensity of exercise can also impact your blood glucose levels. For instance, exercising right after a meal can help to prevent a spike in glucose.
When it comes to exercise intensity, high-intensity workouts rapidly decrease your blood sugar levels (since your body needs a lot of fuel right away), whereas low to moderate intensity can help you maintain more balanced levels of glucose in your blood.
How to manage:
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Exercise at least a few times a week
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Exercise right after a meal to prevent a spike in blood glucose
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Focus on low to moderate-intensity workouts if you want your blood sugar levels to stay stable

4State of mind
Stress can cause a spike in cortisol and adrenaline levels. This results in the liver releasing extra stored glucose into the bloodstream, causing spikes in blood sugar. Finding ways to manage stress is essential for maintaining healthy glucose levels.
How to manage:
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Get regular exercise
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Do a mindfulness meditation
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Practice deep breathing
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Get enough sleep
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Eat a balanced diet
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Focus on family and friends who can support you
5Medication
Taking insulin or certain diabetes medications can lower blood glucose levels. Medication such as metformin is used to lower blood glucose, whereas other substances such as steroids will cause blood glucose levels to increase. Beta-Blockers and some antidepressants may also affect blood glucose levels.
How to manage:
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Be aware of the effect of your medication on blood glucose levels
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Talk to a doctor in case you are not sure
6Caffeine and alcohol Intake

Drinking excessive amounts of alcohol or caffeine can cause your blood sugar to spike. Therefore, it is important to keep track of how much you are consuming and to monitor your blood glucose levels when drinking either.
For caffeine, this response stems from the fact that it is a stimulant and increases cortisol and adrenaline levels, which, in turn, will increase blood glucose levels.
This is especially true for people with diabetes. If you have diabetes, an effect on glucose level might be noticeable after 200mg of caffeine, which correlates with approximately two 8-ounce cups of black coffee. How noticeable that change in blood glucose depends on the individual. Furthermore, one study involving healthy individuals who had caffeinated and decaffeinated coffee after a high glycemic index meal found that insulin sensitivity was reduced by 40% after drinking caffeinated coffee as opposed to decaf.
Similarly, alcohol, also effects blood glucose because it interferes with the liver and its ability to produce glucose. This can lead to a decrease in blood sugar levels.
How to manage:
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Drink caffeine and alcohol in moderation
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Monitor your blood glucose levels when drinking caffeine or alcohol
7Illness
Fevers, infections, or even common colds can cause your body to produce hormones that impact insulin sensitivity, causing your blood sugar to rise.
This is due to a number of different factors. For one, illness causes stress on your body, and as we know, stress hormones also impact blood glucose levels.
However, different medications, a reduction in appetite and food intake, as well as dehydration (all factors that go hand in hand with being sick) can impact your blood glucose levels and cause them to rise.
How to manage:
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Monitor your blood glucose levels when you are sick
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Try to get well as quickly as possible
8Time of day
As the day progresses, the body’s ability to manage glucose becomes more difficult.
It is normal for blood sugar levels to fluctuate throughout the day, but an early morning spike in hormones such as growth hormone, cortisol, and glucagon can cause a spike in blood sugar, called the ‘dawn phenomenon’.
This phenomenon can be managed through various different techniques, like avoiding intake of carbohydrates at bedtime, exercising in the evening, or timing medication such as insulin differently.
How to manage:
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Avoid intake of carbohydrates at bedtime
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Exercise in the evening
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Adjust medication accordingly
Let’s sum up

As you can see, there are various things that can impact blood glucose levels, from what you eat, to what you do throughout the day, to what kind of medication you are taking. Knowing what raises and lowers your blood glucose levels is crucial for finding a balance.
Spikes and crashes will mess with your energy levels and quite simply aren’t healthy for you over time, so taking a look at your current lifestyle, you can use the above tips in order to stabilise your blood sugar levels.
Hungry for knowledge? Here is more
If you want to find out more about blood glucose and how it affects health, we recommend you read the book ‘The Obesity Code’ by Doctor Jason Fung. Dr. Fung has experience treating thousands of patients for decades and shares his insights on weight loss, diets, nutrition, type 2 diabetes reversal, and intermittent fasting.

In the video below, Dr. Fung explains how fasting affects blood glucose and what happens during ‘the dawn phenomenon’.
If you’re interested in learning more about Glucose and Brain Function or the impact of physical activity on glucose, you can check out this part of Andrew Huberman’s Podcast episode “Controlling Sugar Cravings & Metabolism with Science-Based Tools”.