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Understanding Healthy Blood Glucose Levels

How they work and why it matters

So what exactly is blood sugar?

Blood sugar refers to the sugar in our blood that we get from foods containing carbohydrates1 and is a fuel source for our bodies. These sugars can come from a meal you ate recently, or from stores in your body from past meals. Blood transports sugar, which can be broken down to provide energy to cells in any organ that requires it. For this reason, your blood always contains sugar — and that’s a very good thing. Also known as blood glucose, blood sugar, when consumed in balanced amounts, can help us perform many of our daily tasks. That includes everything from thinking to exercising.


Defined: Blood Sugar

Blood sugar, also known as blood glucose, refers to the sugar in our blood that we primarily get from foods, especially those containing carbohydrates.

Why does Blood Sugar Matter?

In the short term, blood sugar keeps the body alive and well. It is a source of energy for cells so they can carry out their functions and contribute to the health of the body. Without the ability to break down food and use it for energy, we would not be able to survive. Healthy blood sugar levels also allow for signals in the body to work properly and can help with our day-to-day mood and feelings (think of being “hangry,” a sign your body needs food right away). Understanding blood sugar levels, including what impacts them, can help us make informed decisions about the foods we eat.

Over many years, keeping blood sugar in a healthy range is important for the health of many parts of the body. They include the brain, kidneys, eyes, nerves, and the cardiovascular system.3 When blood sugar stays high for too long, the body struggles to interpret that information. It will pump out more insulin, but cells do not necessarily respond well to it. This can create a vicious cycle of heightened signals that include elevated blood sugar and insulin — two opposing messages — and it could even lead to organ damage over a long time. Maintaining blood sugar levels in a healthy range in the short-term and long-term can help the body feel good and work properly. Understanding the factors that influence healthy blood sugar levels can help us make the best decisions for our bodies to keep blood sugar balance a reality in both the short- and long-term.

Blood Sugar Basics eBook

Easy ways to improve your health and increase your knowledge about the body’s main energy source.

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How does Sugar Get Into Your Blood?

Foods we eat are a mix of three categories of nutrients that can be used by our bodies: fats, proteins, and carbohydrates. Before these nutrients can be absorbed into the blood, the food we eat must go through several stages of digestion2:

1. Mouth: the mechanical act of chewing plus the enzymes found in saliva begin to break down food into smaller pieces and the absorption of those small pieces into our blood.

2. Stomach: the extremely acidic environment of the stomach, paired with more digestive enzymes, further breaks down food into pieces that can be digested. The fats we eat are broken down into lipids called triglycerides, while dietary proteins are broken down into amino acids, and carbohydrates are broken down into simple sugars (glucose, fructose, and galactose).

3. Intestines: these simple sugars are absorbed from the intestines into the blood stream where they are transported from one location to another.

After the final stage of digestion in the intestines, sugar will be absorbed into the blood stream and travel to organs throughout the body. Once it reaches the pancreas, sugar signals to pancreatic beta-cells to release insulin, a hormone that assists cells in allowing sugar to enter them. When dietary carbohydrates aren’t readily available, the body takes care of energy production in another way. If you haven’t had a meal in a long time, your body will rely on the hormone glucagon to tell other organs to break down their sugar reserves in order to provide energy to cells.


Blood Sugar Terminology

Insulin is a hormone made in the pancreas that lowers blood sugar levels by moving it into cells

Glucagon  is a hormone also produced by the pancreas that raises blood sugar levels

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What Impacts Blood Sugar Levels?

Blood sugar levels are under tight control through insulin and glucagon, but are also influenced by many factors. This can sometimes make it challenging to understand how a certain food might change blood sugar levels.

Within the body, blood sugar levels are determined by how much sugar the intestines can absorb and how quickly cells all over the body will take in the sugar, therefore removing it from the blood. This process can be complex and is simultaneously adaptable and highly regulated. For example, if you go on an early morning bike ride after eating breakfast, your body will quickly shuttle the sugar from your breakfast into cells to power your muscles. If you’re napping later that day, your cells do not require as many resources, so blood sugar transport into cells will likely be minimal. But what else contributes to changes in blood sugar?

The Food We Eat can impact Blood Sugar Levels

The food we eat affects blood sugar levels more than anything else. This can include the quantity and quality of food, how quickly we eat, the frequency of meals, the timing of each meal throughout the day, and how long it takes the body to digest and absorb food.3 Consuming more food or more carbohydrates will result in higher blood sugar levels. Additionally, eating foods that are full of simple sugars, instead of complex starches and fibers, will result in a more rapid rise in blood sugar. Eating too quickly can also raise blood sugar, whereas food that sits in the stomach for a long time will cause a less intense spike in blood sugar levels.3 Scientific studies tell us that the body is best equipped to handle carbohydrates in the middle of the day, around lunch time, so consuming meals that coincide with the body’s natural ability to process dietary sugar can help stabilize blood sugar levels.3 Overall, the carbohydrate content of a meal is the single most important determinant of blood sugar levels.3-5

The Time of Day and Circadian Rhythm can effect Blood Sugar Levels

Time plays an important role in determining blood sugar levels. Circadian rhythm is the scientific term for how time affects each person’s body in a normal cycle. It influences many aspects of blood sugar, including increasing the drive to eat at certain times of day, the speed at which food is broken down into sugar, and how sensitive the body is to the incoming sugar.3,5 Additionally, poor sleep and a late bedtime can affect how the body handles food and blood sugar the next day.6 A large deviation from a normal sleep routine can also negatively affect blood sugar levels.6

Are there other Factors that Impact Blood Sugar?

Exercise can have a big impact on blood sugar because it significantly increases the rate of sugar uptake into cells.3,4,7 It can immediately lower blood sugar levels because exercise can cause muscles to import up to 20 times the amount they normally consume during rest in order to have fuel for activity.4,7 Exercise also has long-term effects on blood sugar because it can help the body stabilize levels and optimize its utilization.4,7 Hormones such as insulin and glucagon also contribute to blood sugar levels as key regulators that control blood sugar and keep levels from getting too high or too low.

Other hormones that impact blood sugar levels include satiety hormones that help the body to know when to stop eating, as well as incretins released from the gut that help the body respond to dietary carbohydrates.3 The gut microbiota can also directly and indirectly impact blood sugar levels - it is involved in the fermentation and absorption of dietary nutrients and has the ability to influence many actions in the body including a healthy inflammatory response and metabolism.8

What External Factors could effect Blood Sugar?

Additional external factors that influence blood sugar include certain medications, infection, stress, and dehydration.9


Blood Sugar Terminology

Incretins  are gut hormones secreted in response to a meal that help stimulate insulin secretion.

Defining Healthy Blood Sugar Levels

Healthy blood sugar levels are the result of the body responding appropriately to the many factors that can influence blood glucose. The body needs to be able to provide sugar to all the organs that need it. This includes the brain, liver, and lungs, which even need energy while we’re sleeping.3,10

A healthy response to eating food results in a peak in blood glucose approximately 90 minutes after a meal, which eventually returns to normal as insulin begins shuttling blood sugar into cells.Blood sugar balance also requires that cells in the body are responsive and sensitive to sugar. Hormones that maintain healthy blood sugar levels must be functional as well.

What Healthy Blood Sugar Levels Are

Blood sugar levels do not stay constant throughout the day; there is a natural cycle to how the body processes sugar that also involves the timing of meals and other aspects of circadian rhythm.5,11 Insulin, the hormone that decreases blood sugar levels, also has a natural cycle during the day with greater levels in the early morning and a dip in the evening.11 It is common for blood glucose levels to be higher in the afternoon. 

With that said, blood sugar levels should remain in a normal range despite natural fluctuations throughout the day. Imbalances in blood sugar levels occur when blood sugar rises too high and/or fails to return to normal in an appropriate amount of time. 

Healthy blood sugar does not mean levels never change; they exhibit a natural cycle throughout the day.

How Meals Impact Blood Sugar Levels

Meals are by far the biggest determinant of blood sugar levels in the body. Understanding how meals impact blood sugar is crucial to supporting healthy blood sugar levels in both the short-term and long-term. Meal composition and meal timing are two of the major meal factors impacting blood sugar levels. The relative contribution of fats, proteins, and carbohydrates determines the blood sugar response.3,13 A meal that is mostly carbohydrates contains more sugar than meals that include more proteins and fats. This results in a more intense impact on blood sugar levels, spiking them shortly after consumption before they rapidly drop as insulin gets to work. A food that contains few to no carbohydrates will have a small or negligible effect on blood sugar levels.

Symptoms of Low And High Blood Sugar Levels

Cells in our bodies need energy to run, and carbohydrates are most efficient at producing this energy from the sugar they provide. Because many organs primarily run on sugar, a minimum consumption of 130 grams of carbohydrates per day should be consumed to maintain the demands by the brain and other processes in the body.24 It may be surprising to learn that the brain is especially sensitive to blood sugar levels, and it is the largest sugar consumer by relative mass in the human body.10 

Fluctuations in blood sugar levels throughout the day and in response to eating meals are common and normal, but what happens if blood sugar levels get off balance?

 If blood sugar levels get too low — perhaps due to prolonged fasting— there may be noticeable symptoms that include sweating, feeling hungry or anxious, weakness, confusion, seizures, feeling shaky, fast heartbeat, nausea, blurred vision, and headache.18 If blood sugar levels get too high — possibly from eating a high carbohydrate meal, stress, or illness — the person may experience confusion, nausea or vomiting, shortness of breath, increased thirst and frequent urination.17

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Additional Resources

How to Naturally Maintain Blood Sugar Levels with Nutrition Checklist

How Your Body Uses Glucose 4 Tips for Optimization and Regulation

3 Unexpected Triggers for Your Body’s Blood Sugar to Rise

Blood Sugar Levels What They Mean, How to Check Them, and What a Normal Blood Sugar Level Is [Chart]

Blood Sugar Basics eBook

Easy ways to improve your health and increase your knowledge about the body’s main energy source.

Download eBook

Blood Sugar Balance Supplements

Healthy blood sugar levels involve many moving pieces and sometimes it can be difficult to fully understand why or how levels are changing. The type and timing of food we consume play a large role, along with hormone levels and physical activity. For additional nutritive support to help support healthy blood sugar already in a normal range, try plant-based supplements that support a reduction of post-meal glycemic response in healthy individuals.*

Work with your health care practitioner to find an appropriate dietary pattern, sleep schedule, and exercise habits to support long-term health and overall wellness as it relates to healthy blood sugar levels already in a normal range.

Whole Food Fiber

Whole Food Fiber is a good source of dietary fiber from nutrient-rich whole foods.

Metabol Complex

Metabol Complex contains Fenugreek, Black Cumin seed, Bitter Melon and Cinnamon to provide multi-action metabolic support.*


Diaplex, a chromium supplement, supports healthy sugar handling to help maintain blood sugar levels already within normal range.*

Glucose Assist™ 

New Glucose Assist™: Healthy Blood Glucose Level Support* Supplements

^with levels already in a normal range


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2. Lovegrove, A., Edwards, C.H., De Noni, I., Patel, H., El, S.N., Zielke, G.C., Ulmius, M., Nilsson, L., Butterworth, P.J., Ellis, P.R., Shewry, P.R. (2017). Role of polysaccharides in food, digestion, and health. Crit Rev Food Sci Nutr, 57(2):237.

3. Papkonstantinou, E., Oikonomou, C., Nychas, G., Dimitriadis, G.D. (2022). Effects of Diet, Lifestyle, Chrononutrition, and Alternative Dietary Interventions on Postprandial Glycemia and Insulin Resistance. Nutrients, 14(4):823.

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5. Henry, C.J., Kaur, B., Quek, R.Y.C. (2020). Chrononutrition in the management of diabetes. Nutr Diabetes, 10(1):6.

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7. Erickson, M.L., Jenkins, N.T., McCully, K.K. (2017). Exercise after You Eat: Hitting the Postprandial Glucose Target. Front Endocrinol, 8:228.

8. Sharma, B.R., Jaiswal, S., Ravindra, P.V. (2022). Modulation of gut microbiota by bioactive compounds for prevention and management of type 2 diabetes. Biomed Pharmacother, 152:113148.

9. Loneman, S.M. Blood sugar levels can fluctuate for many reasons. (2022, June 7). The Mayo Clinic. glucose-levels/faq-20424316

10. Palombit, A., Silvestri, E., Volpi, T., Aiello, M., Cecchin, D., Bertoldo, A., Corbetta, M. (2022). Variability of regional glucose metabolism and the topology of functional networks in the human brain. Neuroimage, 257:119280.

11. Rybicka, M., Krysiak, R., Okopień, B. (2011). The dawn phenomenon and the Somogyi effect- two phenomena of morning hyperglycaemia. Endokrynol Pol, 62(3):276.

12. Schmidt, M.I., Hadji-Georgopoulos, A., Rendell, M., Margolis, S., Kowarski, A. (1981). The dawn phenomenon, an early morning glucose rise: implications for diabetic intraday blood glucose variation. Diabetes Care, 4(6):579.

13. Kheriji, N., Boukhalfa, W., Mahjoub, F., Hechmi, M., Dakhlaoui, T., Mrad, M., Bahlous, A.H.S., Amor, N.B., Jamoussi, H., Kefi, R. (2022). The Role of Dietary Intake in Type 2 Diabetes Mellitus: Importance of Macro and Micronutrients in Glucose Homeostasis. Nutrients, 14(10):2132.

14. Shehadeh, M.B., Suaifan, G.A.R.Y., Abu-Odeh, A.M. (2021). Plants Secondary Metabolites as Blood Glucose-Lowering Molecules. Molecules, 26(14):4333.

15. de Paulo Farias, D., de Araújo, F.F., Neri-Numa, I.A., Pastore, G.M. (2021). Antidiabetic potential of dietary polyphenols: A mechanistic review. Food Res Int, 145:110383.

16. Kim, Y., Keogh, J.B., Clifton, P.M. (2016). Polyphenols and Glycemic Control. Nutrients, 8:17.

17. American Diabetes Association. Hyperglycemia ( Accessed 7/12/2022.

18. American Diabetes Association. Hypoglycemia ( Accessed 7/12/2022.

19. Vlachos, D., Malisova, S., Lindberg, F.A., Karaniki, G. (2020). Glycemic Index (GI) or Glycemic Load (GL) and Dietary Interventions for Optimizing Postprandial Hyperglycemia in Patients with T2 Diabetes: A Review. Nutrients, 12(6):1561.

20. American Diabetes Association. Consensus Statement: Postprandial Blood Glucose. Diabetes Care, 24(4):775.

21. Vega-López, S., Venn, B.J., Slavin, J.L. (2018). Relevance of the Glycemic Index and Glycemic Load for Body Weight, Diabetes, and Cardiovascular Disease. Nutrients, 10(10):1361.

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23. Bao, J., Atkinson, F., Petocz, P., Willett, W.C., Brand-Miller, J.C. (2011). Prediction of postprandial glycemia and insulinemia in lean, young, healthy adults: glycemic load compared with carbohydrate content alone. Am J Clin Nutr, 93(5):984.

24. Evert, A.B., Dennison, M., Gardner, C.D., Garvey, W.T., Lau, K.H.K., MacLeod, J., Mitri, J., Pereira, R.F., Rawlings, K., Robinson S., Saslow, L., Uelmen, S., Urbanski, P.B., Yancy, W.S. (2019). Nutrition Therapy for Adults With Diabetes or Prediabetes: A Consensus Report. Diabetes Care, 42(5):731.