Using a Blood Sugar Chart to Understand Glucose Readings by Mehdi Yacoubi

Using a Blood Sugar Chart to Understand Glucose Readings
Posted on
July 22, 2021

Blood sugar (also called blood glucose) is the main source of fuel and energy for our bodies. Healthy blood sugar levels help regulate metabolic health, control bodily functions, and fight disease — while low or high blood sugar levels can significantly harm your health. 

When tracking your blood glucose, you can use a blood sugar chart to see if your readings are within normal levels, are too high, or are too low. This information can then help you make informed decisions about your personal diet and exercise. 

If you are looking to optimize your health, managing blood sugar levels is an excellent place to start. In this article, we are going to discuss what blood glucose is, how to test it, and the factors that influence your blood sugar. We’ll also share a blood sugar chart and explain how to use it.

What Is Blood Glucose?

As the name implies, blood glucose is simply the sugar that is in your bloodstream — also referred to as blood sugar levels. When you eat, there is an increase in blood sugar, especially if you eat foods that contain carbohydrates. 

Carbohydrates are the main source of blood glucose — the more carbs you eat, the more blood sugar you’ll get. Once your body converts the digested food to sugar, it will enter your bloodstream to be later used as your body’s energy source.

After the sugar joins your bloodstream, your pancreas will produce the hormone insulin to utilize the blood sugar as an energy source. It does so by bringing your blood sugar from your bloodstream and safely transporting it to your cells. The same process explains how insulin lowers your blood sugar levels and keeps them in normal ranges.

How to Use a Blood Sugar Chart

Blood sugar levels are measured relative to the time of meals — that is, before you eat and after you eat. Generally, blood sugar is measured in the morning before you eat (fasting) and after meals. 

Here is a blood sugar chart that shows possible blood glucose ranges. When you test your blood sugar, choose the column based on when you last ate. You’ll then see if your blood sugar levels are normal or high. We’ve also included a chart that shows normal levels during pregnancy.

blood sugar chart for normal ranges
blood sugar chart of normal ranges during pregancy

What Do Your Readings Mean?

Now that you’ve seen the blood sugar chart, let’s talk about what you need to know and what your readings might be telling you.

Things to Know About Fasting Levels

When you take your fasting blood sugar measurement, to make it as accurate as possible, be sure that the last time you ate was 12 hours ago. This usually means you’ll be taking your reading in the morning before you eat breakfast. A fasting blood sugar level will show how your body processed your blood sugar overnight.

Your body naturally raises your blood sugar level as it prepares itself for the upcoming day. If your blood sugar measures normal at this time, it means that your insulin is properly processing and countering the blood sugar raise.

Things to Know About Measuring Blood Sugar After Eating

Measuring your blood sugar after eating is also important because it shows two things: 

  • How the foods you ate (and the amount you ate) affected your blood sugar
  • How your insulin processed your after-meal sugar spikes

If your blood sugar reading is higher than the after-meal normal blood glucose level, then tweaking your meal may do the trick. For instance, change the foods you eat and/or reduce the number of foods you eat. Also, keep in mind that carbohydrates bring in the most sugar — the more carbohydrates you eat, the more blood sugar you’ll get.

If your blood sugar remains high despite tweaking your meal, it may mean that your insulin is not processing your blood sugar properly. This is also known as “insulin resistance.” When that happens, your blood sugar is less and less processed, which means that more and more blood sugar stays in your bloodstream, hence the high blood sugar readings

What If Your Readings Are High?

If your readings are outside the normal levels on the blood sugar chart, your measurements may be indicative of either prediabetes or diabetes.

Prediabetes is a condition where your blood sugar level is high, but not high enough to be considered diabetes. Still, prediabetes should not be taken lightly. If you are not careful, your blood sugar level may rise to more dangerous levels, which can ultimately lead you to diabetes.

The good thing about prediabetes is that it’s reversible. With lifestyle changes, you can return to a normal and healthy blood sugar level and avoid progressing to diabetes.

It’s important to know that even if you are seeing at-home readings that are consistently high, you should not diagnose yourself. See a healthcare provider for further testing.

What If You’re Pregnant?

Even if you aren’t a diabetic, it’s possible to develop gestational diabetes during pregnancy. This unfortunately has become a common condition amongst pregnant women and is usually something that is checked for by your doctor. Your doctor will often perform an oral glucose tolerance test to look for gestational diabetes. If you have the condition, your doctor will develop a treatment plan.

Keep in mind that gestational diabetes usually goes away on its own soon after delivery.

Ways to Measure Blood Sugar Levels

blood sugar chart: man monitoring his glucose on his phone

When it comes to monitoring blood sugar levels, there are a variety of options that you can choose from. You can either test your blood glucose at home or have it tested by your healthcare provider. You can use the test results to make sure you're meeting your blood sugar goals or to develop a treatment plan if you're not.

Here are some of the common ways you can measure your blood sugar.

Continuous Glucose Monitor

A continuous glucose monitor, also known as a CGM, is one of the more popular testing methods for both diabetics and non-diabetics. A CGM involves wearing a sensor to keep tabs on your blood sugar throughout the day. Typically, it’s placed on someone's upper arm for two weeks at a time, which allows it to track glucose levels in real time. This is a great option if you are wanting to see how your food impacts your blood sugar levels or if you are looking for more data around your health. 

This type of monitor provides you with things like a blood sugar target range to stay within, how exercise impacts your blood sugar, and tips to lower blood sugar levels. While it was once just a tool for those with diabetes, it is now commonly used by health enthusiasts, or those trying to prevent diabetes from happening. 

Finger-Stick Blood Test

Another test that is cost-effective and easy to do from home is the finger-stick blood test. You make a small prick on the top of your finger, and then place a drop of blood on a test strip that’s inserted into a blood glucose meter. While this is a good option for monitoring your blood sugar levels, it can be tedious if you need to test multiple times a day. In these cases, a CGM may be a better option.

A1C Test

The A1C test, also known as the HbA1c test or hemoglobin A1C, is a blood test performed in a doctor’s office. The A1C results represent your average blood glucose levels over the past three months.

This test is supported by the American Diabetes Organization, the European Organization for the Study of Diabetic Issues, and the International Diabetic Issues Federation to detect prediabetes, Type 1 diabetes, Type 2 diabetes, and diabetes complications. 

Fasting Blood Sugar Test

This is a one-time test that is done in a doctor's office or diabetes center after a night of fasting. This is typically done to determine if someone is diabetic or not. If the range falls between 70 to 100 mg/dl or 3.9–5.5 mmol/L (average blood sugar levels for fasting), then the person is not diabetic. If it is outside that range, then the doctor will follow up with more testing. 

Factors That Impact Blood Sugar Levels

variety of fruits on a wooden table

If you are looking to manage your blood sugar levels and the amount of glucose in your bloodstream, there are a variety of factors that come into play. 

For instance, if you exercise regularly, this will help balance your blood sugar levels, whereas if you never exercise, it will put you at risk for blood sugar spikes. Similarly, if you drink adequate amounts of water each day, it will support your blood sugar, while drinking minimal amounts will harm it. 


Regular exercise helps in lowering and controlling your blood sugar by increasing your insulin sensitivity, or your body’s ability to recognize insulin’s call. This is virtually the opposite of insulin resistance. Aside from that, regular exercise lowers your blood sugar since physical and muscular exertion uses blood sugar to keep up with the physical demand.

Weightlifting, bodyweight exercises, and cardio exercises such as jogging and biking all help in lowering and controlling your blood sugar.

A great way to keep your blood sugar as balanced as possible is to go for a walk post-meal. Even if you ate a balanced meal, this is a great way to avoid a spike in levels.

Water Consumption

Even the simple act of drinking water can help in lowering your blood sugar. This is because drinking water can force your kidneys to flush out excess sugar in your bodies. According to the U.S. National Academies of Sciences, Engineering, and Medicine, men should aim for 15.5 cups of fluids a day, and women should aim for 11.5 cups a day. 

Some go as far to argue that drinking enough water can even help lower blood sugar levels. In a 2011 study, 3,615 men and women with normal blood sugar levels drank different amounts of controlled water. For those that drank more than 34 ounces, they were found to be 21% less likely to develop hyperglycemia than those that drank 16 ounces or less. This was predicted to apply to the following 9 years.

Nutrient Intake

Some nutrients play a role in regulating your blood sugar, and if you have low levels or are deficient in these nutrients, you’ll be more prone to high blood sugar among other health problems that the deficiency may bring.

Two of the best nutrients when it comes to blood sugar control are chromium and magnesium. In addition to blood sugar control, chromium also aids in carb and fat metabolism. On the other hand, magnesium plays a lot of vital roles in our health in addition to regulating our blood sugar levels.

Carb Intake

As mentioned earlier, we get glucose or sugar from carbs. Therefore, it makes sense to say that monitoring and controlling your carb intake can help you in lowering your blood sugar levels.

Sleep Quality

There’s no need to explain the importance of sleep — we simply love it! But unfortunately, many of us still suffer from sleep deprivation, and sleep deprivation has health consequences including high blood sugar levels and an increased risk of diabetes.

To begin with, poor sleep can increase your appetite, which can ultimately lead to weight gain. Also, poor sleep increases certain hormones such as cortisol and growth hormones, both of which play a role in our blood sugar level.

Start Monitoring and Managing Your Blood Sugar Levels

Whether you are just getting started on your blood sugar journey, or you’ve been doing it for a while, knowing how to read a blood sugar chart is key. This chart can help you navigate your levels and show you what you can improve upon. 

If you are looking to manage your blood sugar, improve your health, boost your metabolism, or increase your longevity, continuous glucose monitoring can help. Sign up today for Vital to begin understanding your blood sugar levels and receive personalized recommendations about exercise, food, and daily habits.

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