Everyone’s talking about blood glucose levels (or blood sugar levels), but do you know enough about what they are and why they’re essential to focus on? And even with all the information available about them, do you know what “normal” blood sugar levels mean?
If not, don’t worry. It can be challenging to sift through everything to figure out precisely what a good range is for your blood sugar levels, why you should focus on them, and how to monitor them. Luckily, we’re here to help!
First, you should know that glucose is the main sugar found in your blood. The simple carbohydrate is your body’s primary energy source and comes from many foods, such as bread, fruits, and vegetables. A target range for blood glucose levels is important because the amount of glucose in your blood changes throughout the day.
Here’s more about blood glucose and what normal blood glucose levels look like.
What is Blood Glucose (aka Blood Sugar)?
Glucose (C6H12O6 if you’re ever on Jeopardy!) is a simple sugar—the most basic of all carbohydrates. Blood sugar, or blood glucose, is the sugar that circulates in your bloodstream and provides your body with energy.
Your body constantly regulates your blood sugar levels to keep them within a normal range. Glucose levels, in particular, are regulated by the hormone insulin released from the pancreas. While insulin can help reduce blood sugar levels, hormones like glucagon and cortisol can raise blood sugar.
When your blood glucose levels are too high, your body releases insulin to bring them back down. When your blood glucose levels are low, your body releases glucagon to raise them.
Here’s a fun fact: the average person has about one teaspoon of sugar in their bloodstream at any given time. If your blood sugar levels rise too far above or below that one teaspoon, your pancreas releases hormones to keep the balance.
When you have too much sugar in your blood, it leads to elevated blood glucose levels, also known as hyperglycemia. It can happen after a meal or if someone has diabetes. Things like excessive thirst, fatigue, and blurred vision are often symptoms, leading to severe complications like ketoacidosis if left untreated.
What are Normal Blood Glucose Levels for People without Diabetes?
Blood glucose levels vary from person to person and depend on various factors, including medical conditions like diabetes. For those who don’t have diabetes, a normal range can vary according to whether you have a healthy diet and lifestyle factors like sleep hygiene and blood pressure.
It’s important to note that there is no one-size-fits-all answer to this question. Typical blood glucose levels can vary depending on age, weight, and activity level. Stress, illness, and certain medications can also affect your blood sugar levels—everything from a heart attack to a new weight loss goal can impact them. So if you’re wondering what average blood glucose levels look like for you, it’s best to talk to a healthcare provider.
The NutriSense Nutrition Team recommends a daily average glucose of <105 mg/dL for a healthy individual, with fasting values between 70-90 mg/dL. It’s also best to avoid repeated spikes of >140 mg/dL.
Here are some general guidelines for average blood glucose readings.
Fasting Blood Sugar Levels
The medical definition of a “fast” is when you go more than eight hours without food and drink only water. So, first thing in the morning after eight hours of rest, for example. It’s why fasting blood glucose levels are usually recorded just before breakfast.
The American Diabetes Association (ADA) describes average fasting blood glucose as anything under 100 mg/dL. The World Health Organization (WHO) provides a similar fasting range of 70-100 mg/dL.
But a fasting blood glucose level near 100 mg/dL isn’t always ideal. Research shows that people with fasting blood glucose levels consistently between 91-99 mg/dL are more likely to develop diabetes.
The ADA recommends seeing your healthcare provider if you get two consecutive results above 100 or below 70 mg/dL.
Blood Sugar Levels Two Hours After Eating
It’s also important to know how your body responds to the foods you eat. Glucose is a simple carbohydrate, so the carbs in your diet like bread, beer, and potatoes can cause higher spikes in your blood glucose.
Balancing your meals with proteins and fiber-filled foods is a great way to balance those carbohydrates out and keep your levels stable. It’s also an excellent way to nurture a healthy diet to optimize your health.
The scientific term for this post-meal test is a postprandial glucose test (PPG). The ADA says that for those without diabetes, a two-hour postprandial glucose test should show blood sugar levels between 70-140 mg/dL.
Some research suggests the sweet spot for PPG two hours after eating should be under 100 mg/dL.
Maximum or Peak Glucose Levels
Eating provides your body with the energy it needs for the next five to six hours of your day. So, it’s not surprising that your blood glucose levels spike immediately after a meal.
As a healthy adult, your readings directly after a meal should be <140 mg/dL. Remember, keeping your blood sugar levels below this threshold can also help minimize the risk factors for medical conditions like prediabetes.
Regardless of mitigating factors like eating patterns, any two tests (taken two hours apart) that show blood sugar levels over 200 mg/dL can be concerning. And, if you have readings over 200 mg/dL, it’s a good idea to contact a healthcare provider without delay.
What are Normal Blood Glucose Levels for People with Diabetes?
While everyone should focus on optimizing their blood glucose levels, it’s often part and parcel of the treatment plan for those with diabetes. Diabetes, known medically as diabetes mellitus, is a group of disorders related to an abundance of glucose in the blood.
If your body cannot produce enough insulin, your healthcare provider will likely diagnose you with type 1 diabetes. Type 2 diabetes occurs when your body cannot properly regulate and use blood glucose due to issues like insulin resistance.
The average blood sugar levels for those living with diabetes are slightly different from those without diabetes. And pregnant women who may develop gestational diabetes have different ranges too.
Individual factors such as age and medical history can also change what an average level looks like for you.
It’s always best to find your ideal range from a doctor, but if you’re curious about what average blood glucose ranges look like for those with diabetes, read on.
Fasting Blood Glucose Levels
Proper diabetes management requires regular testing. For many people with diabetes, that means taking a fasting blood glucose test before breakfast.
According to the ADA, fasting blood sugar levels of 99 mg/dL are normal, 100 to 125 mg/dL indicate the possibility of prediabetes, and 126 mg/dL or higher indicates diabetes.
Two-Hour Postprandial Blood Glucose Levels
The two-hour PPG test is another benchmark for those managing diabetes. The ADA says a two-hour PPG blood sugar level of 140 mg/dL or lower is considered normal.
Much like the blood sugar guidelines for those without diabetes, the ADA’s postprandial blood glucose level recommendation should serve as the upper limit.
Our dietitian, Cheri Bantilan adds, “For healthy individuals striving for optimal levels, we like to see two-hour postprandial blood glucose values <100 mg/dL, and/or a return to preprandial values. A good response would be <120 and/or a return to preprandial values.”
Peak Glucose Value
With or without diabetes, blood glucose levels usually peak around 30 to 60 minutes after eating. For those with diabetes, a good target range is blood sugar levels less than 80 mg/dL higher than a test taken before the meal.
The closer your post-meal and pre-meal blood sugar readings, the better. Readings over 240 mg/dL can be dangerous, so it’s best to consult a doctor if you see those.
A1C or Average Glucose Readings
The Glycated hemoglobin, or A1C test, is a medical blood test result used to gauge how much glucose has been in a person’s blood over three months. It reflects an average of the ups and downs of blood glucose levels over a longer time.
Most people with diabetes can expect an A1C test anywhere between twice and six times a year and aim for levels below 7 percent. A1C test results are also known as Estimated Average Glucose (eAG) Level tests. An A1C level of 7 percent correlates to an eAG of 154 mg/dL.
How to Check Your Blood Glucose Levels
Blood sugar levels can vary, but the guidelines and resources in this article can help you determine if you’re within a healthy target range. If you’re still confused by all the numbers, here’s a handy list of blood sugar charts by age!
And if you’re struggling with unstable blood glucose levels or want a deeper understanding of your body’s metabolic health, try these tools.
Glucometer
A glucometer is a medical device with which you can measure the sugar level in your blood. Small, portable, and easy-to-use, it involves pricking your finger, touching a drop of blood to the test strip, and letting the machine do the rest.
The most obvious drawback of this blood sugar meter is the finger prick. Glucometers also need a constant supply of testing strips, and while some come equipped with onboard memory, most do not. You’d need to keep a journal to write down the time of each test and the corresponding blood sugar level.
Continuous Glucose Monitors
CGMs continuously measure and record a person’s blood sugar levels. They are a sensor placed on the skin, usually on the “fatty” part of your upper arm. They have a small filament that gets inserted under the skin and are an excellent option for those looking to get real-time readings to understand their blood glucose trends.
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Hemoglobin A1C Test
The A1C hemoglobin test is a physician-ordered test that involves a blood sample. Because A1C levels aren’t as dependent on immediate external factors such as recent diet and exercise. These tests provide a bigger-picture look. A1C tests are a helpful way to see how dietary and lifestyle changes have affected blood glucose levels over time.
Pros of A1C Tests
- Provides a big-picture by capturing a three-month average blood sugar level
- Better at diagnosing hyperglycemia than fasting glucose
- Better marker for side effects of diabetes like kidney disease
- No fasting is necessary
- Less prone to individual genetics
Con of A1C Tests
- Misses spikes and valleys in blood sugar and only captures the average
- Often fails to diagnose asymptomatic diabetes
- It can be a lagging metric for catching early deviations in glucose levels
- Red blood cells often vary in length, making standards for A1C tests unreliable
- Poor predictor of cardiovascular risk
Fructosamine
Fructosamine is a compound produced in the body when glucose combines with protein. Like A1C hemoglobin, measuring fructosamine levels provides another stable benchmark. For those diagnosed with diabetes, the doctor-administered test can reveal how diet and lifestyle changes affect blood sugar in as little as two weeks. Because fructosamine testing does not rely on hemoglobin, it can provide more accurate results for those with atypical blood cells.
Oral Glucose Tolerance Test
The oral glucose tolerance test is a doctor-prescribed test that gauges how your body reacts to an influx of glucose. They are a standard test during pregnancy to check for gestational diabetes. The test begins with a blood draw to determine a baseline blood sugar level. Then, the patient drinks eight ounces of liquid glucose—usually a total of 75 grams of carbohydrates. After a few hours, the test requires another blood draw to see how your body handles the influx of glucose.
A Note on Hypoglycemia and Diabetes
With all the talk of high blood sugar, it’s easy to forget that low blood sugar can also be an issue—especially for people with type 1 or type 2 diabetes. Too much insulin can lead to hypoglycemia or unhealthily low blood sugar levels. For those with diabetes, blood sugar levels below 70 mg/dL are hypoglycemic levels.
Learn more about very low blood sugar levels (hypoglycemia) and high blood sugar levels (hyperglycemia) here.
