Skip to content

Diabetes Health Center

Font Size

Glucose Testing: After Meals?

Should diabetics test their blood sugars after eating, too? The debate continues.

The Proponents continued...

While there haven't been a great number of studies of postprandial hyperglycemia, there have been a number of suggestive studies of something called post-challenge hyperglycemia. Post-challenge glucose tests are administered after a person takes a set amount of glucose, usually 75 mg in a liquid form. The precise relationship between post-challenge hyperglycemia and postprandial hyperglycemia has not been firmly established, but proponents cite a few studies that indicate a good correlation.

"There's a lot of epidemiological evidence coming from all over the world suggesting that post-challenge blood sugars and thus postprandial blood sugars have their own independent risks or at least greatly augment understood risks," says Jellinger. "We thought that it was in our patients' best interest to bring this issue to light."

Experts have been focusing an increasing amount of attention on the cardiovascular risks of diabetes -- such as heart attack and stroke -- and some epidemiological studies have suggested that postprandial hyperglycemia is directly related to cardiovascular complications.

In addition, some suggest that postprandial testing may detect people with impaired glucose tolerance (IGT) or impaired fasting glucose (IFG) -- so-called "pre-diabetes" -- who might be missed by fasting tests.

"Epidemiological evidence suggests that there are a lot of people out there who don't have diabetes and who don't have pre-diabetes but have abnormal postprandial glucose levels," Ganda tells WebMD. "And based on a number of studies in the U.S. and Europe, they may be at an increased risk of cardiovascular disease."

The Problems

However, not everyone agrees that postprandial testing is so important. No one debates that people with diabetes are more likely to have postprandial glucose spikes -- or excursions -- than those without diabetes. What is debated, and debated fiercely, is whether these spikes require any specific treatment separate from typical care for diabetes.

"I think that the recent attention to postprandial glycemia is a distraction," says David M. Nathan, MD, director of the diabetes center at Massachusetts General Hospital and a professor of medicine at Harvard Medical School. "In general, postprandial glycemia, fasting glycemia, and chronic glycemia, as measured by the A1c test are highly correlated. Attention should just be focused on overall lower glycemia."

Nathan points to the biggest problem with the postprandial hyperglycemia hypothesis. While epidemiological research has suggested a connection between postprandial hyperglycemia and diabetic complications, this sort of research looks at a large number of variables and isn't designed to test postprandial hyperglycemia specifically. There isn't yet a method to single out the particular effects of postprandial hyperglycemia from other common risk factors like hyperglycemia, obesity, and hypertension. As a result, there's no way to know if postprandial glucose levels really matter on their own.

"I just don't think postprandial testing is worth putting energy into now, because if you look for other risk factors of diabetes, you will find all of these people anyway," says David E. Goldstein, MD, principal investigator from the health sciences center at the University of Missouri School of Medicine. "There just isn't evidence that postprandial glucose levels matter independent of other factors, like A1c."

"But it's a hot topic now, though," Goldstein says wearily. "It's a snake pit, or a bottomless pit. I don't know what to call it."

Is This Normal? Get the Facts Fast!

Check Your Blood Sugar Level Now
What type of diabetes do you have?
Your gender:

Get the latest Diabetes newsletter delivered to your inbox!


Your level is currently

If the level is below 70 or you are experiencing symptoms such as shaking, sweating or difficulty thinking, you will need to raise the number immediately. A quick solution is to eat a few pieces of hard candy or 1 tablespoon of sugar or honey. Recheck your numbers again in 15 minutes to see if the number has gone up. If not, repeat the steps above or call your doctor.

People who experience hypoglycemia several times in a week should call their health care provider. It's important to monitor your levels each day so you can make sure your numbers are within the range. If you are pregnant always consult with your health care provider.

Congratulations on taking steps to manage your health.

However, it's important to continue to track your numbers so that you can make lifestyle changes if needed. If you are pregnant always consult with your physician.

Your level is high if this reading was taken before eating. Aim for 70-130 before meals and less than 180 two hours after meals.

Even if your number is high, it's not too late for you to take control of your health and lower your blood sugar.

One of the first steps is to monitor your levels each day. If you are pregnant always consult with your physician.

Did You Know Your Lifestyle Choices
Affect Your Blood Sugar?

Use the Blood Glucose Tracker to monitor
how well you manage your blood sugar over time.

Get Started

This tool is not intended for women who are pregnant.

Start Over

Step:  of 

Today on WebMD

Diabetic tools
Symptoms, diagnosis, treatment, and more.
woman flexing muscles
10 strength training exercises.
Blood sugar test
12 practical tips.
Tom Hanks
Stars living with type 1 or type 2.
Woman serving fast food from window
Can Vinegar Treat Diabetes
Middle aged person
are battery operated toothbrushes really better

Prediabetes How to Prevent Type 2 Diabetes
type 2 diabetes
food fitness planner
Are You at Risk for Dupuytrens Contracture