What are Blood Sugar Levels?

What are Blood Sugar Levels?

Blood sugar is the amount of available sugar, or glucose, at any given time throughout the day. The body converts the food we eat into smaller molecules and nutrients so that it can be absorbed into the body and blood stream. Glucose is one of those molecules found in most of the foods we eat at each meal. Glucose is found in foods containing carbohydrates such as rice, bread, fruits, starchy vegetables, and sweets. Sugar is an important source of energy and provides nutrients to the body's organs, muscles, and nervous system.

The way blood glucose is regulated is when glucose enters the bloodstream after a person has eaten food rich in carbohydrates and/or sugars the pancreas produces and releases a hormone known as insulin. Insulin helps move the sugar from the blood into your cells and converts any extra into glycogen (stored glucose) to be used for later when blood sugar drops below a certain level. The pancreas also produces a hormone called glucagon, which does the opposite of insulin, raising blood sugar levels when needed. The two hormones work together to keep glucose balanced.

How diet and lifestyle affect blood sugar levels

Keeping your blood sugars within a normal range can be difficult if you don't know what can cause spikes in these levels throughout the day. Many things can impact how your blood sugar levels change including food, exercise, and stress.

Let's look at how food can impact these levels first. This may be a surprise to some but It's not only the type of food you eat, but also how much you eat and the combinations of food types you eat that impact blood sugar. Carbohydrates are often the macronutrient that impacts your blood sugar levels most as they are rich in glucose whereas fat and protein have minimal effect on blood sugar when consumed. There are different sources of carbohydrates that are absorbed at different rates in the body which have an impact on how high your blood sugar will rise. Carbs coming from beverages consumed alone are absorbed more quickly than those from the food you chew. So having a pop will cause a faster rise in your blood sugar levels than eating a burger or pasta. Fiber is one component of carbohydrates that isn’t converted into sugar as it can’t be digested. Including fiber at each meal from fruits, vegetables, whole grains, and legumes is a great way to help keep your blood sugar from spiking at each meal.

Exercise plays another important role in your blood sugar levels. When you exercise, your muscles use glucose for energy which helps your body use insulin more efficiently. These factors work to lower your blood sugar levels during and after working out. The more strenuous your workout, the longer the effect lasts. Even light activities such as housework, gardening or being on your feet for extended periods can improve your blood sugar.

Stress impacts more than just our mood; it can also play a role in our blood sugar levels. When the body perceives stress it triggers the pancreas to stop producing insulin to allow insulin levels to lower while glucagon and epinephrine (adrenaline) levels rise and more glucose is released from the liver. At the same time cortisol levels rise, which causes the body to be less sensitive to insulin. As a result, more glucose is available in the bloodstream.

Blood sugar and diabetes 

Diabetes and blood sugar go hand in hand. Diabetes occurs when the body is unable to control blood sugar levels within a normal range so often-times those with uncontrolled diabetes have extremely high levels of blood sugar which overtime can cause lasting damage to many areas of the body.

There are 2 types of diabetes. Type 1 Diabetes is when the body is unable to make its own insulin to control blood sugar levels while Type 2 Diabetes is when the body has a hard time responding to the insulin produced in the body, also known as insulin resistance. Your pancreas will start producing more insulin to try to get cells to respond and reduce glucose levels in the blood but eventually your pancreas can’t keep up, and your blood sugar rises. 

Monitoring and managing blood sugar levels 

Those who have diabetes and take insulin to manage blood sugar levels more than likely use a glucose monitoring device to manage and track blood sugar levels throughout the day. Those who do use a device to track their blood sugar should check their levels when waking and before you eat/drink anything, before meals/snacks, about 2 hours post eating and before going to bed.

A normal fasting blood sugar level would be around 99 mg/dL for a healthy individual. For those with diabetes typically their levels will be a bit higher around 126 mg/dL or above. Two hours after a meal those with diabetes should aim to have their glucose levels below 180 mg/dL and for those without diabetes a good level to be around is 140 mg/dL. 1

If you do not track your blood sugar levels daily some other ways to help keep your levels stable throughout the day can include eating at regular times of the day and not skipping meals, choosing foods higher in fiber, protein and healthy fats, staying hydrated and limiting sugar sweetened beverages, reducing alcohol intake and limiting processed foods high in added sugar as much as possible.

Foods that spike blood sugar 

Managing your blood sugar does not mean giving up your favorite foods, however those who have diabetes or are at risk should focus on moderation when consuming foods that can spike blood sugar levels to help prevent further damage of blood vessels, heart and nerve function.

Some foods that should be consumed  in moderation and limited as much as possible are2

  • Sugary and sweetened drinks- coffees, juices, soda, and sports drinks
  • Added sugars in processed foods
  • White rice, breads, and pastas
  • Baked goods 
  • Starchy vegetables such as potatoes, corn and peas
  • Dried fruits
  • yogurts with added sugars

Pairing foods more likely to spike your blood sugar should also be paired with some protein and fat. Adding protein and fat to foods that are known to spike blood sugar can help minimize the spike and slow the digestion of these simple carbs.

Glycemic Index and Low GI Foods

You may have heard of the glycemic index but understanding what the glycemic index is, is another thing. The glycemic index is a measurement of how foods raise our blood glucose after eating them. Foods are ranked on a scale of 0 to 100, with pure glucose (sugar) given a value of 100. The lower a food's glycemic index, the slower blood sugar rises after eating that food. For those looking to manage their blood sugar levels it is best to focus on foods lower on the index while pairing higher GI foods with protein, fat and fibers to prevent the high rise in blood sugar levels.

Here are some low GI foods to focus on the next time you go grocery shopping3:

  • Cereals: Steel cut oatmeal, Oat bran
  • Fruits: Apples, apricots, blackberries, blueberries, cherries, cranberries (not dried), grapefruit, peaches pears, raspberries, tangerine, and Strawberries
  • Vegetables: asparagus, artichoke, avocado, broccoli, cabbage, cauliflower, celery, cucumber, eggplant, greens, lettuce, mushrooms, peppers, tomatoes, onions, spinach, summer squash, zucchini 
  • Grains: barley, rye, bulgur, wild rice, whole wheat
  • Nuts, olives and oils: almonds, peanuts, pecans, sunflower seeds, hazelnuts, olives walnuts, oils that are liquid at room temperature 
  • Dairy, fish, meat, soy and eggs: skim milk, soy milk, almond milk, low fat cheese, yogurt (low fat or Greek) lean red meat, fish, skinless chicken and turkey, shellfish, egg whites, egg yolks

To give you a better idea on how other foods rank here is a list of moderate and high glycemic foods to help you pick the best option to fit your goals4:

  1. Moderate glycemic index (GI 56 to 69): White and sweet potatoes, corn, white rice, couscous, breakfast cereals such as Cream of Wheat and Mini Wheats.
  2. High glycemic index (GI of 70 or higher): White bread, rice cakes, most crackers, bagels, cakes, doughnuts, croissants, most packaged breakfast cereals.

While many conventional sweets and treats do have a high GI, there are certain companies out there creating good for you desserts that are made with low GI ingredients like Keto Foods. Their products are created specifically to help minimize blood sugar spikes while satisfying any sweet tooth! So just because managing your blood sugar is a priority in your life does not mean you have to go without your favorite foods!


  1. https://www.cdc.gov/diabetes/basics/getting-tested.html#:~:text=A%20fasting%20blood%20sugar%20level,higher%20indicates%20you%20have%20diabetes
  2. https://professional.diabetes.org/sites/professional.diabetes.org/files/media/All_About_Carbohydrate_Counting.pdf 
  3. https://www.nhrmc.org/~/media/testupload/files/low-gylcemic-meal-planning.pdf 
  4. https://www.health.harvard.edu/healthbeat/a-good-guide-to-good-carbs-the-glycemic-index 


  • Blood sugar is the amount of available sugar, or glucose, at any given time throughout the day.
  • Diabetes occurs when the body is unable to control blood sugar levels within a normal range.
  • The glycemic index is a measurement of how foods raise our blood glucose after eating them. Foods are ranked on a scale of 0 to 100, with pure glucose (sugar) given a value of 100.

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