Why knowing your blood sugar level is important and how you can manage it

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Dr. Kaberi Dasgupta wants to set the record straight on blood sugar levels.

The professor of medicine at McGill University says people often think high blood sugar levels are from eating too much sugar.   

That could be to blame for high blood sugar levels, but most of the time, she says excess weight and lack of physical activity are the causes. 

“People think they’re just going to get rid of or reduce sugar in their diet,” said Dasgupta, who is also the director of the Centre for Outcomes Research and Evaluation at the Research Institute of the McGill University Health Centre.

Instead of focusing on sugar alone, dietitians say people should focus on eating foods that don’t cause high spikes in blood sugars, like fibre and protein. 

“If you’re someone who is struggling later on in the day, you want to really look at your meals to make sure that they’re giving you enough nutrients so that your blood sugar is balanced so you’re able to be your best,” Toronto-based registered dietitian Anar Allidina told CBC’s The Dose podcast host Dr. Brian Goldman. 

Diabetes is a major health issue in Canada, with one in three Canadians living with diabetes or prediabetes, according to the charity Diabetes Canada. 

Diabetes can be caused by a range of factors depending on the type of diabetes, according to the charity’s website. However, prediabetes and type 2 diabetes are largely preventable. 

For those with diabetes, high blood sugar can lead to health problems like kidney disease and vision loss, according to the U.S. Centers for Disease Control and Prevention (CDC). 

Here’s what Dasgupta and dietitians recommend to those wanting to better regulate their blood sugars. 

How do I know if I have high blood sugar?

Blood glucose, or blood sugar, is the main sugar found in your blood. High blood sugar usually happens in people who have diabetes that isn’t well-controlled, and symptoms can range from mild to severe, according to MyHealthAlberta‘s website. 

Mild symptoms include fatigue, anxiety, thirst and increased urination. 

More severe symptoms include blurred vision, flushed skin and trouble waking up.

For people with diabetes, keeping your blood glucose in the healthy range should be the target, according to Diabetes Canada‘s website, which has a list of the target ranges for certain age groups. 

Glucometers are the common tool of choice for many with diabetes to test blood sugars at home. 

Some factors increase a person’s risk for diabetes, say CDC officials. 

For the more commonly diagnosed type 2, risk factors include:

• Those who have prediabetes
• Those who are overweight 
• People who are 45 years or older 
• Physically active less than three times a week

To assess their risk, Dasgupta recommends that those who haven’t been diagosed with prediabetes or diabetes start with the Public Health Agency of Canada’s diabetes risk questionnaire.

If someone’s risk is calculated as moderate to high, she says “that might be a moment to go to a drop-in clinic and get your blood sugar measured.”

She says most people should get their first blood sugar test done at or around the age of 40. 

“If it all looks good, you can wait up to five years before having another blood test,” she said.

But those who are at a higher risk of type 2 diabetes — like people with a family history of diabetes — should be tested more often, she says.

How does diet affect blood glucose?

In general, foods with higher glycemic indexes are going to raise your blood sugar levels higher and faster than those with a lower rating, according to Diabetes Canada.  

Allidina says that eating fibre-rich foods and protein can be great ways to stabilize blood sugars throughout the day. 

If you experience cravings in the afternoon, try consuming more fibre at lunch.

“So if you are having a sandwich, opting for a whole grain or rye sourdough that’s going to give you that fibre is going to slow down how your food is digested,” she said.

Toronto-based registered dietitian Andy De Santis also recommends people incorporate more fibre into their diets. Specifically, he’ll encourage clients to eat more legumes — a food group he says is the most underrated.� 

“These foods have incredible amounts of fibre. They have almost no effect on blood sugar levels,” he said.

De Santis also advises people to eat consistently throughout the day and on a predictable schedule to keep blood sugars from hitting those peaks and valleys. 

Should I cut out sugar?

Allidina and De Santis agree that people should never cut out sugar completely from their diet.

Your brain is one of the largest consumers in the body of glucose and needs it to properly function, Allidina says.

But according to De Santis, it’s important to remember that not all sugar is created equal and that fruits and vegetables are generally made up of glucose that will release more slowly into the bloodstream compared to processed sugar. 

“An orange has more sugar than a cup of white rice, but a cup of white rice will cause a much bigger spike in blood sugar levels,” De Santis says.

Instead of cutting out sugar, Allidina says to look at how you can add more nutrient-dense foods to your diet to replace foods filled with processed sugar.

“It’s just being strategic and figuring out what you can add to whatever you enjoy that’s going to give you the nutrients like healthy fats, fibre and protein, which is going to slow down the way those sugars are absorbed in your body,” she said.

The role of exercise

Exercise can lower blood glucose levels in both the short and long-term, according to the American Diabetes Association’s website. 

The authors of a clinical research study published in the American Journal of Medicine Open in June say more research is needed to figure out what the “optimal exercise dose” is for blood glucose. 

They said 150 minutes of moderate to vigorous physical activity per week typically recommended for adults is a good benchmark. 

They said breaking up down time with smaller bouts of exercise each hour — like taking 250 steps per hour — or being active a few times throughout the day may also work well for blood sugar management. 

For those who don’t know where to start, Dasgupta usually recommends people turn to walking to increase their physical activity.

Most people should aim for 7,000 steps at least per day, she says. 

Resistance training can further lower our blood sugars and reduce our risk for type 2 diabetes, she added.

Other factors

A lack of sleep and stress can also both have an effect on blood sugar levels, Dasgupta says. 

CDC officials say getting less than seven hours of sleep per night regularly can make diabetes harder to manage, with less sleep creating an increase in insulin resistance for example. Insulin is a hormone that helps blood sugar enter cells to be used for energy. Insulin resistance is when your body can’t use insulin right away so sugar doesn’t move into your cells and stays in your blood instead, according to HealthLinkBC’s website.  

Dasgupta says the younger we are when we improve our diets, sleep and exercise habits, the more it will pay off later in life by delaying or lowering the risk for type 2 diabetes.

She compares it to saving money for retirement.

“If you’re walking a bit more from the beginning, if you’re exercising a bit more from the beginning, if your diet is just a bit better, then over time that is going to have a favourable impact.”