What’s the Best Time to Test Blood Sugar After Eating?

The best time to test blood sugar after eating is 2 hours after the start of a meal, but you should monitor your blood sugar at other points throughout the day.

A large part of managing blood sugar levels involves checking them regularly throughout the day. Testing lets you know if your treatment and lifestyle changes are working well to manage type 2 diabetes.

Results that fall outside the normal range may signal a need to change how you manage the condition.

Why test blood sugar?

Your blood sugar readings give you a pretty direct way to see how well you’re managing type 2 diabetes. These readings can also give you a good idea if it’s time to switch things up, like changing your current medications or reevaluating what foods you eat.

With treatment, like medications and lifestyle changes, you should expect your fasting blood sugar levels to fall between 80 mg/dL and 130 mg/dL. When they fall within this range, you have generally well-managed diabetes.

Your blood sugar level should not rise above 180 mg/dL following a meal.

Regular blood sugar testing lets you know you’re falling within your target range. When blood sugar dips below 70 mg/dL, you may experience hypoglycemia (low blood sugar) symptoms like dizziness, sweating, palpitations, or blurred vision.

Blood sugar levels that surge beyond the normal fasting range are considered high. Symptoms may include an increased need to urinate, changes in mood, and excessive thirst.

Over time, living with high blood sugar levels can cause damage to different parts of your body, such as your kidneys and blood vessels.

It can also increase your risk of several complications, including:

• kidney disease
• heart disease
• nerve damage
• issues with your eyes
• hearing loss
• changes in your skin
• problems with your feet and lower extremities

Regularly checking your fasting blood sugar levels can help you decide if your lifestyle choices and treatments are working. If you’re constantly testing outside the range, your doctor will probably need to adjust your care to help you keep your blood sugar levels balanced.

When should you test blood sugar?

Check your blood sugar several times throughout the day.

The following is a breakdown of the generally recommended times, but keep in mind that your treatment team may give you additional instructions on when to test.

First thing in the morning

Consider testing your blood sugar levels on an empty stomach when you first wake up before you reach for that cup of coffee.

The morning blood sugar test can help show you if you experience the dawn phenomenon. During the early morning hours, several changes in your body trigger your liver to release glucose (sugar) into your bloodstream.

The increase in blood sugar levels helps you get the energy you need to wake up and start your day, but it can also cause an unexpected spike.

If you consistently test high in the morning, consider talking with someone on your medical team to manage your morning levels.

Before and after meals

You may be instructed to check your blood sugar before and after meals. Before a meal, your blood sugar should be between 80 mg/dL and 130 mg/dL.

Two hours following the start of a meal, your blood sugar should be below 180 mg/dL.

Before and after exercise

Sometimes, a healthcare professional may have you check your blood sugar levels before and after exercise. This is often the case if you take insulin or often test positive for low blood sugar levels.

Before bedtime

You should also check your blood sugar levels before bed. Going to bed with high blood sugar means you may have elevated levels overnight for several hours.

Going to bed with blood sugar that’s too low may mean you won’t wake up if you experience symptoms related to low blood sugar levels.

Testing before bed can help you and your treatment team decide on the best course of action, such as eating a snack before bed (if the level is too low) or taking a dose of medication (if it’s too high).

Other times

Your doctor or treatment team may recommend you test more frequently. Factors such as age and other conditions can affect how your body deals with blood sugar, which may mean you need more frequent testing.

How to test blood sugar

There are two main ways to check blood sugar levels at home: continuous glucose monitoring (CGM) and finger prick tests.

A CGM regularly monitors your blood sugar levels without a need to always prick your finger. But due to differences in machines, you will need to make sure your machine is calibrated and may still need to prick your finger occasionally.

A finger prick and blood glucose meter are accurate ways to test blood sugar levels throughout the day. A healthcare professional can help train you on the proper use of either testing method.

What should your blood sugar targets be?

The Centers for Disease Control and Prevention (CDC) recommends that your fasting blood sugar levels (after being asleep or before meals) should fall between 80 mg/dL and 130 mg/dL.

Two hours after a meal, it should be less than 180 mg/dL.

If you fall outside the normal range, you may need to retest. If you consistently find yourself outside this range, you should let a member of your treatment team know so they can help make adjustments to your treatment plan.

FAQs

What if my blood sugar is high?

High blood sugar can damage the eyes, kidneys, blood vessels, nerves, and other areas of the body, causing symptoms and increasing the risk of developing complications.

What if my blood sugar is low?

Low blood sugar levels can also be dangerous. Your doctor has probably told you how to bring your levels up with a snack or drink. Consider asking which type of snack or drink might be best for you.

Symptoms of too-low blood sugar can include dizziness, loss of vision, sweating, or other unusual symptoms.

Could my results be false?

In some cases, yes. Factors that can affect the accuracy include faulty equipment, a dirty device, or not washing your hands properly before using a meter.

If you suspect your readings at home are false, consider letting your healthcare team know so they can help determine what the issue may be.

Can I use expired test strips?

It’s better to replace expired test strips to avoid the possibility of inaccurate test results.

How can I manage my blood sugar?

You can take several steps to manage blood sugar levels, including:

• taking medication or insulin as prescribed
• monitoring your blood sugar regularly
• eating a balanced diet including fiber, vegetables, fruits, healthy fats, and lean protein
• exercising regularly
• getting regular sleep
• managing stress levels
• eating at regular times and limiting your portions
• avoiding alcohol or limiting to less than two drinks a day for men or one drink a day for women
• drinking water instead of soda, fruit juice, or other sugary beverages

How do carbs affect my blood sugar?

Carbs fall into different categories. Simple carbs are various forms of sugar. Your body quickly absorbs sugars and passes them into your bloodstream, potentially leading to a spike in blood sugar levels.

Complex carbs are digested more slowly and are made up of fiber and starch.

Fiber slows down how quickly glucose enters your bloodstream, so eating high fiber carbs will impact your levels less.

Limiting your simple carb intake, increasing your fiber intake, and eating fats and proteins with carbs can help prevent spiking blood sugar levels.

Takeaway

Consider your doctor’s recommendations for checking your blood sugar levels regularly. That might look like testing throughout the day, including in the morning, around meals, and before bed.

The best time to test blood sugar after eating is about 2 hours after you start your meal. Your doctor may recommend testing before starting your meal, too.

If you take insulin or consistently have low blood sugar readings, you should talk with a doctor about testing before and after exercise.

Monitoring your blood sugar levels can help you prevent unsafe spikes or drops in blood sugar.