Postprandial Blood Sugar – Why Should You Test Your Blood Sugar After Meal?

The postprandial blood sugar test helps check the effectiveness of a body’s response to sugar and starch after a meal. It is usual for one’s blood sugar to abruptly rise after one eats food.

The main purpose of checking one’s postprandial blood sugar is to ensure that these are not exceeding their target range. Insulin, the pancreatic hormone, starts responding instantly by enabling the bloodstream to transport sugar to the body cells, tissues, and muscles.

The Two-Hour Postprandial Glucose Level Test as it is otherwise called, works to ensure sugars return to their normal after two hours of having the meal. If not, it may suggest that one is a diabetic or a pre-diabetic. 

Why Should One Test Blood Sugar After Meals?

The term, “postprandial” signifies ‘after meals.’ As stated above, checking one’s blood sugar levels two hours after one has started eating helps ascertain how food affects a change in one’s blood sugar levels. Of note, these tend to be within the normal target range, i.e., between 80 and 130 mg/dL, before one starts with the meals for the day. However, it abruptly rises the moment one has eaten the food.

Often referred to as the “Two-hour Postprandial Blood Sugar Test”, this is a definitive marker of diabetes. if a person’s blood sugar does not automatically drop to its normal state after the two-hour mark, this may indicate problems with his/her insulin.

One should note here that Physicians generally recommend postprandial blood sugar checks on patients whom they suspect to be diabetics. At other times, this test is also taken to rule out the possibility of the same. 

Criteria For Checking Postprandial Blood Sugar

The following signs happen to be the chief criteria for checking postprandial blood sugar.

Criteria For Checking Postprandial Blood Sugar

Of note, these are the ones that suggest diabetes or problems with insulin.

  • Blurred Vision
  • Frequent Urination
  • Unusual Thirst
  • Tiredness
  • Non-healing foot ulcers
  • Recurring infections

Of note, pregnant women can also avail this blood sugar test. This helps them to ensure that their gestational blood sugar levels, especially those after meals, are staying within the targeted range. Expectant mothers are prone to developing gestational diabetes. Thus, the two-hour postprandial blood sugar will help a physician to appropriately treat and/or manage their blood sugar levels.

How To Check Postprandial Blood Sugar?

Individuals undergoing blood sugar checks need to fast for 12 hours before the test. The next step is to eat a meal that should contain a minimum of 75 grams of carbohydrates. One is advised not to eat anything after this meal. This is to ensure an accurate reading of the blood sugar levels postprandially.

Further, patients/individuals are to rest for the two-hour waiting period and not engage in any form of exercise. This is because exercise will cause blood sugars to rise, in turn, affecting the quality and accuracy of the test.

What Other Tests Should Accompany The Postprandial Blood Sugar Checks?

Even though after-meal sugar level checks help convey diabetes onset, these are not enough to confirm the same. Hence, these mandate additional tests as included below:

? Fasting blood glucose Test: Requires measuring the amount of glucose in the blood in a fasting state of at least eight hours.

? Hemoglobin A1C Test:  Measures one’s average blood sugar levels over the last 2-3 months.

? Glucose Tolerance Test: A body’s ability to use sugar after consuming a sugary drink in a standard amount is checked in this test.

Factors Influencing Postprandial Blood Sugar Checks

Age, gender, and health history have been recognized to be the most prominent factors affecting after-meal blood sugar results. Test results depend on the lab that conducts the same.

? Age: The normal results based on age when taking postprandial blood sugar level tests reveal less than 140 mg/dL for non-diabetics. Whereas, it is less than 180 mg/dL for people with diabetes.

? Gender: Women are usually found to have more insulin sensitivity than men when undergoing postprandial and glucose tolerance tests. Lower fasting glucose values and higher stimulated glucose concentrations after 2 hours of oral glucose loading are often seen in females.

? Health History: Specific health conditions, such as hormonal disorders, diabetes, and gastrointestinal disorders can alter/influence blood glucose level tests. These are highly displayed during the two-hour postprandial blood sugar checks.

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Postprandial blood sugar tests provide a gateway to the exact diagnosis of diabetes. Increased blood sugar levels upon eating one’s meals for a day that gradually subside after two hours is a sure-shot determiner for developing early diabetes.

However, this will require other related tests, such as fasting glucose intolerance, hemoglobin A1c, and glucose intolerance tests to confirm the diagnosis.

Several factors influence test results for blood glucose after a meal at the two-hour mark. Age, gender, and health history are the most prominent among these. Expecting mothers also require undergoing postprandial blood sugar checks to rule out gestational diabetes and effective treatment-cum-management if found positive.


? Kautzky-Willer, A. and Mihaljevic, L.K.J.L.R. (2015) Gender-based differences in glycaemic control and hypoglycemia prevalence in patients with type 2 diabetes: Results from patient-level pooled data of six randomized controlled trials. A Journal of Pharmacology and Therapeutics.

? Radcliffe Labs (?) PPBS Test – Price, Procedure, Normal Range & More. Available at:,levels%20and%20PPBS%20Test%20results. (Accessed: 6 September 2023).
? University of Rochester Health Center (2023) Two-hour Postprandial Glucose. Available at: Two-Hour Postprandial Glucose – Health Encyclopedia – University of Rochester Medical Center (Accessed: 5 September 2023).

About the Author

Nicole Carter is a dedicated and passionate nutritionist, committed to helping individuals achieve their health and wellness goals through the power of proper nutrition. With a Bachelor's degree in Nutritional Science and years of practical experience.

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