What Are Normal Blood Sugar Levels for Non-Diabetic People?

Find out what normal glucose levels are for non diabetics, what to do when glucose spikes and more.

woman wearing a continuous glucose monitor holding a smart phone and looking at it
Caitlin Beale, MS, RDN
— Signos
Health & Nutrition Writer
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Updated by

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Science-based and reviewed

May 20, 2024
August 10, 2021
— Updated:
May 31, 2023

Table of Contents

Many people think of blood sugar as something that only people with diabetes need to think about, but the truth is that everyone can benefit from knowing their blood glucose levels.

Diabetes is often called a silent disease because there aren’t many symptoms, especially in the beginning. You can have high blood sugar levels or insulin resistance for years before developing diabetes. Blood sugar dysregulation and higher insulin levels can make it harder to lose weight, impact energy levels, and even affect mood.

This article will help you understand normal blood sugar ranges, why glucose matters for your health, and what steps you can take to stabilize your blood sugar.

What is Blood Sugar?

Glucose, or blood sugar, is the main sugar found in your blood and serves as your body’s primary energy source. Several hormones, including insulin, control the glucose levels in your blood. When your glucose is elevated, insulin gets released by the pancreas to move the glucose into cells for immediate energy. Glucose that isn’t used gets stored for later, often as fat. 

Many foods that you eat can increase the glucose in your body. In an ideal state, your body’s complex hormonal responses will keep glucose in a relatively “normal” range. However, excess fat, insulin resistance, pre-diabetes, and other factors can cause higher, longer glucose spikes. 


Blood Sugar, Blood Sugar Spikes, and Diabetes

To better understand what's considered normal for blood sugar levels, it helps to know what happens when blood sugar is out of range and why it happens.

As discussed above, when your body operates normally, your pancreas releases insulin when your glucose levels are higher than normal. The insulin signals your body to absorb the glucose until your levels are normal. 

However, if you are living with diabetes, your body either does not make insulin (type 1 diabetes) or does not respond normally (type 2 diabetes). This can result in your blood sugar levels remaining high for too long and possibly damaging nerves, blood vessels, and other serious health issues.

What is Hypoglycemia?

Hypoglycemia occurs when an individual has low blood sugar or when the glucose in your blood drops below 70 milligrams per deciliter (mg/dL). Some people will have a different range of normal (i.e., a lower normal range). For people who are not on diabetic medicines like insulin, sustained hypoglycemia is extremely rare. 

One of the most common causes of true hypoglycemia is accidental low blood sugar from medications that treat diabetes, like insulin or sulfonylureas. People who have had bariatric surgeries can also experience hypoglycemia events.

Other causes of hypoglycemia include critical illness, malnutrition, and a variety of rare conditions like insulin-secreting tumors and adrenal insufficiency (when your adrenal glands do not produce enough steroids like cortisol).

All of these are serious conditions, and anyone with them should be under the direct care of a healthcare provider.

Most commonly, people think low blood sugar results from not eating enough or from burning a lot of fuel during a long cardio workout. However, being “hangry” does not usually mean you are at a dangerously low level of blood glucose.

Severe hypoglycemia happens when your blood glucose drops so low that you cannot do anything for yourself, and you should seek treatment immediately. This severe condition is most common in people who need to take insulin or other medications to lower their blood sugar. 

What is Hyperglycemia?

On the other end of the spectrum, hyperglycemia occurs when this is too much glucose in your blood. Sustained hyperglycemia over a consistent period is a symptom of diabetes. It can lead to the following diabetes complications and risk factors:

  • Diabetic retinopathy: abnormal blood vessels on the retina that can cause vision impairment
  • Nephropathy: impaired kidney function that can lead to kidney disease
  • Neuropathy: nerve damage
  • Coronary artery disease: plaque buildup in your arteries that could eventually lead to a heart attack
  • Cerebrovascular disease: impairs blood flow to the brain, which could lead to stroke
  • Depression
  • Diabetic ketoacidosis (DKA): a medical emergency that requires immediate attention and could lead to organ damage, brain swelling, muscle weakness, and a heart attack or heart failure.

For people who are not diagnosed or living with diabetes, hyperglycemia is seen when your blood glucose levels are greater than 125 mg/dl while fasting. If an individual lives with pre-diabetes, their fasting glucose levels will be between 100 and 125 mg/dl. 

If you are already living with diabetes, hyperglycemia is considered to be a blood glucose level of more than 180 mg/dl when measured post-meal (between one to two hours after eating). This can also vary depending on the individual and target time-in-range, so please discuss this with your healthcare provider.

What Affects Blood Glucose Levels

Foods you consume

The biggest factor influencing blood glucose levels is your food choices. A healthy diet can reduce blood glucose spikes, increase glucagon secretion, and improve insulin sensitivity. 

Pair carbohydrates with proteins and healthy fats to help reduce insulin spikes. Try to avoid highly processed foods, added sugars, high glycemic index foods, and excessive alcohol consumption. Instead, prioritize healthy eating and incorporate healthy fats, complex carbs, whole grains, and protein into your meals.

When you eat

This may surprise some, but meal timing also impacts blood sugar levels. Our bodies have natural circadian rhythms or daily physical, mental, and behavioral cycles. These rhythms are determined by an internal biological clock that responds to light and darkness in the environment. 

Circadian rhythms affect everything from hormones to body temperature to metabolism. And when these rhythms are disrupted, it can lead to metabolic issues like insulin resistance. 

Remember the saying that breakfast is the most important meal of the day? It turns out there may be some truth to it, and it may be related to circadian rhythms. One study found that insulin sensitivity (or how responsive the cells are to insulin) was 54 percent higher before noon than at midnight. 

Another study found that when men with pre-diabetes ate earlier in the day (before 3 p.m.), metabolic markers like insulin sensitivity, blood pressure, and oxidative stress all improved compared to a regular 12-hour eating window.

Health conditions

Health conditions, such as diabetes and obesity, can directly affect your body’s ability to produce and use insulin. Since insulin is critical in regulating glucose levels, the type of diabetes you may be living with or other health conditions can impact your blood sugar levels.


The US Department of Health states that up to 300 minutes of moderate-intensity aerobic exercise is an effective target if your goal is weight loss and blood sugar control.

However, an activity done for more than this recommended time frame may not lead to better outcomes. There is such a thing as “too much” when it comes to exercise, so make sure you are giving yourself proper rest and talk to your doctor, personal trainer, or other health and wellness practitioner about what is right for you.


Medications can affect different people in various ways and also influence glucose levels. If you are living with diabetes, it may be helpful to compare your blood sugar levels before and after taking medication to understand how it personally impacts your body.


A lot goes on in your body while you’re sleeping. Aside from dreaming, memory formation, muscle repair, and other functions, your body actively manages glucose during slumber.

In people with diabetes, early morning blood sugar levels may read very high due to insulin resistance or lack of insulin production. This is called the Somogyi effect and, if persistent, can lead to a high A1C and related health complications.

The Somogyi effect is thought to be a rebound reaction to low blood sugar and is the body’s attempt at “rescuing” you from low blood sugar while you sleep.


Epinephrine, cortisol, growth hormone, and glucagon—the stress hormones—work together to release glucose into your bloodstream, among other changes. These changes help you stay sharp, focused, and give you extra energy.

Your adrenal glands release adrenaline and cortisol to encourage your liver to produce more glucose. During stress, glucose levels rise to further promote the production of glucose. Growth hormone, secreted from the pituitary gland in your brain, also halts the effects of insulin.

This sophisticated system works well when you need to deal with a real threat or challenge.But when you're constantly stressed out, your blood sugar levels can remain high. 

To counteract high glucose levels, your pancreas releases insulin to either help your body use or store excess glucose. Over time, chronically elevated insulin levels may lead to insulin resistance, where you need even more insulin to help the cells absorb the extra glucose in the blood. Insulin resistance may lead to type 2 diabetes and other chronic illnesses.

Does a Blood Sugar Spike Mean You Have Diabetes?

Occasional high spikes don’t mean you have diabetes. It’s normal for your blood sugar to go up after eating a meal high in carbohydrates or even due to lifestyle habits and events. Besides food, stress, lack of sleep, age, menstrual cycle, physical activity, and even being sick can affect your blood sugar.

What affects one person's blood sugar may also affect yours differently. In addition, we can all have different responses to food, so monitoring the overall trend of your blood sugar gives you the most insight into your overall health. 

However, while infrequent spikes aren't a problem, it's time to take a closer look at what's contributing if they happen more regularly.

What Are Normal Blood Sugar Levels? Non-Diabetic vs. Diabetic

What Are Normal Blood Glucose Levels for People Without Diabetes?

Normal blood glucose ranges for people without diabetes are:

  • Fasting: 70-90 mg/dl (100-125 mg/dl for those with pre-diabetes)
  • Pre-meal: 70-100 mg/dl
  • Post-meal: less than 126 mg/dl or less than 140 mg/dl at 2 hours post-meal
  • A1C: 4-5.6%
  • Time-in-range: 90% of the day within 70-120 mg/dl

Most blood sugar charts show recommended levels as a range, allowing for individual differences. Some people may find they have much lower blood sugar while others hover a bit higher, but the ranges above are considered diagnostic cut-offs by medical professionals.

Note: The Signos app uses a slightly different range to support weight loss, as you’ll learn about more below.

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What Are Normal Blood Glucose Levels for People Living With Diabetes?

People living with diabetes will often have higher blood sugar targets or “acceptable” ranges than those without the condition. However, these levels can also vary individually depending on a person’s treatment goals.

According to the American Diabetes Association (ADA), target blood sugar levels for people with diabetes are as follows:

Pre-meal glucose:

  • 80-130 mg/dL. This target is for people living with type 1, 2, and gestational diabetes.

Post-meal glucose: 

  • Type 1 diabetes: 90-160 mg/dl
  • Type 2 diabetes: less than 180 mg/dl
  • Gestational diabetes: 120-140 mg/dl

Blood Sugar Metrics You Should Check

When determining your blood sugar levels, several factors can be involved, and one measurement may not give you the full picture. Below are some popular blood sugar metrics that you may come across:

Fasting Glucose

This measurement is your glucose level after fasting for 8 hours. If your fasting glucose level is below 90 mg/dl, you are not considered pre-diabetic or diabetic.

Pre-meal Baseline Glucose

This is your blood sugar level before eating. It should be one of your lowest readings. A level between 70-100 mg/dl is considered the target for non-diabetics.

Post-meal Glucose

This will be the reading or spike that you will have between 45 and 60 minutes after eating

24-hour Glucose

This is your average glucose level over 24 hours. A level between 89-104 mg/dl is considered the target for non-diabetics.


A1C is the standard metric for people living with diabetes. It is the average blood glucose reading measured over 2 to 3 months. For non-diabetics, the A1C level should be between 4 and 5.6 percent.


Considered the gold standard, this number is the percentage of time you have spent within a target range.

How to Test Your Blood Sugar Levels

There are four blood glucose tests used to test blood sugar levels. Blood glucose is measured in milligrams per deciliter (mg/dL), but you may also see test results listed in mmol measurements. Always discuss test results with a healthcare professional if you have questions.

Plasma Glucose Test

This blood sugar test randomly analyzes your blood sugar anytime, doesn't require fasting, and involves the lab technician taking a blood sample. If you fall within the range of below 200 mg/dl, you are considered non-diabetic. 

Fasting Glucose Test

The fasting glucose test is administered after an individual fasts for at least eight hours. This is normally a blood test and measures the glucose in your blood rather than your urine. If you receive a test result that shows your fasting blood glucose is below 100 mg/dl, then you are considered non-diabetic.


Often used in pregnancy, the oral glucose tolerance test (OGTT) requires drinking a specific amount of glucose and testing glucose at one, two, and sometimes hours after. If your test results in a level higher than 200 mg/dL after two hours, you may be living with diabetes and need to speak with your medical professional about possible next steps.

HbA1c Test

The HbA1c test, also known as an A1C test or hemoglobin A1C test, does not directly measure your blood glucose levels but instead looks at the average of your levels for two to three months. If your average blood sugar level is below 6%, then you are considered to be within the normal range. If you are over 6.5%, you are considered to be living with diabetes.

Continuous Glucose Monitors

While not an official test, continuous glucose monitors (CGMs) are utilized for non-diabetics and people living with diabetes to measure blood glucose levels in real-time. A CGM sensor is painlessly implanted into your arm or upper stomach and can be worn continuously for 10-14 days. A small filament on the backside of the CGM sensor sits just below the skin. The filament tracks and records the glucose levels in the interstitial fluid (a fluid that fills the spaces between your cells). 

The sensor takes a glucose reading every 5-15 minutes, even while you sleep. The data is sent via Bluetooth to your smartphone, where you can review trends or any noteworthy changes in blood sugar levels.

Frequently Asked Questions

What should my blood sugar be 1 to 2 hours after eating?

A person without diabetes should have a blood glucose level of less than 140 milligrams per deciliter (mg/dL) one to two hours after eating.

What should my blood sugar be 3 hours after eating?

A person without diabetes should drop close to fasting levels, usually below 126 milligrams per deciliter (mg/dL) three hours after eating.

What is a good blood sugar level in the morning?

Your blood sugar should be between 70 to 90 mg/dL in the morning before eating anything.

What levels of blood sugar are dangerous?

Fasting blood sugar levels above 100 indicate pre-diabetes and anything above 126 is considered diabetes.

Does blood sugar rise with age?

Blood sugar rises as you age, possibly related to insulin resistance or the pancreas making less insulin.

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Topics discussed in this article:


  1. National Institute of Diabetes and Digestive and Kidney Diseases. “Low Blood Glucose (Hypoglycemia) | NIDDK.” Accessed May 26, 2022. https://www.niddk.nih.gov/health-information/diabetes/overview/preventing-problems/low-blood-glucose-hypoglycemia
  2. Mazze, R.S., Strock, E., Wesley, D., Borgman, S., Morgan, B., Bergenstal, R., & Cuddihy, R. (2008). Characterizing Glucose Exposure for Individuals with Normal Glucose Tolerance Using Continuous Glucose Monitoring and Ambulatory Glucose Profile Analysis. Diabetes Technology & Therapeutics 10(3), 149-159. https://doi.org/10.1089/dia.2007.0293
  3. National Institute of Diabetes and Digestive and Kidney Diseases. “Diabetes Tests & Diagnosis | NIDDK.” Accessed May 26, 2022. https://www.niddk.nih.gov/health-information/diabetes/overview/tests-diagnosis
  4. “The Big Picture: Checking Your Blood Glucose | ADA.” Accessed May 26, 2022. https://www.diabetes.org/healthy-living/medication-treatments/blood-glucose-testing-and-control/checking-your-blood-sugar
  5. Juvenile Diabetes Research Foundation Continuous Glucose Monitoring Study Group, Fox, L. A., Beck, R. W., & Xing, D. (2010). Variation of interstitial glucose measurements assessed by continuous glucose monitors in healthy, nondiabetic individuals. Diabetes care, 33(6), 1297–1299. https://doi.org/10.2337/dc09-1971
  6. Chia, C. W., Egan, J. M., & Ferrucci, L. (2018). Age-Related Changes in Glucose Metabolism, Hyperglycemia, and Cardiovascular Risk. Circulation research, 123(7), 886–904. https://doi.org/10.1161/CIRCRESAHA.118.312806
  7. Ojo, O., Ojo, O. O., Adebowale, F., & Wang, X. H. (2018). The Effect of Dietary Glycaemic Index on Glycaemia in Patients with Type 2 Diabetes: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Nutrients, 10(3), 373. https://doi.org/10.3390/nu10030373
  8. Chia, C. W., Egan, J. M., & Ferrucci, L. (2018). Age-Related Changes in Glucose Metabolism, Hyperglycemia, and Cardiovascular Risk. Circulation research, 123(7), 886–904. https://doi.org/10.1161/CIRCRESAHA.118.312806

About the author

Caitlin Beale is a registered dietitian and nutrition writer with a master’s degree in nutrition. She has a background in acute care, integrative wellness, and clinical nutrition.

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