What Does Postprandial Mean?

How to Understand Postprandial Blood Sugar Readings

Nurse giving blood sugar test to patient in home. Credit: Terry Vine / Getty Images

Postprandial means "after a meal." You might have heard the word in the context of postprandial plasma glucose. This refers to your blood sugar levels one to two hours after the start of a meal. Preprandial blood glucose, on the other hand, refers to your blood sugar levels before a meal; if you haven't eaten in at least eight hours it may also be known as the fasting blood glucose levels.

What Are Normal Postprandial Glucose Levels?

For healthy adults, normal postprandial glucose levels is less than 140 mg/dl.

A postprandial glucose reading of 140-199 mg/dl mg/dl indicates prediabetes. A postprandial reading over 200 mg/dl indicates diabetes.

For nonpregnant adults with diabetes, the American Diabetes Association recommends a postprandial glucose target of less than 180 mg/dl. The American Association of Clinical Endocrinologists suggests a postprandial glucose goal of <140mg/dl for people with diabetes, since this is a postprandial glucose number rarely exceeded by people without diabetes.

However, depending on your personal health condition, your doctor may set postprandial glucose readings that are different than these guidelines, so make sure you know what numbers you're shooting for.

Why Do Postprandial Plasma Glucose Readings Matter?

Your postprandial plasma glucose readings tell you how efficiently your body is clearing glucose from your bloodstream after you've eaten.

When you eat, the carbohydrates (and a small amount of the protein) that you've ingested change into glucose, which gets absorbed into your bloodstream.

In response, your pancreas releases insulin, which helps move glucose out of the bloodstream and into cells where it can be used as energy. In a healthy state, your body regulates the amount of insulin that's released, resulting in optimal blood sugar readings--ones that are neither too high (hyperglycemic) or too low (hypoglycemic).

In diabetes, this balance of insulin and glucose is disrupted.

In type 1 diabetes, that's because the pancreas stops making insulin, so your body can no longer bring glucose into the cells and your blood sugar levels get very high after ingesting carbohydrates. In this case, you need to take insulin through and insulin pump or injections.

In type 2 diabetes, the pancreas either isn't making enough insulin, or your cells become resistant to insulin, so it's less effective at bringing glucose from the blood into your cells. This type of diabetes can be managed through diet, exercise, medication and, if needed, insulin.

How Do I Use My Postprandial Plasma Glucose Readings?

When you have diabetes, it's important to check your blood sugars before and after you eat. In addition to checking them, you should also keep a record so you can get a sense of your blood sugar trends over time (and figure out what's influencing your blood sugar--what you ate, how much exercise you got, your stress levels).

Doing so can help you and your doctor know how well your treatment is working. It can help you adjust your behaviors in the short term, so that you won't be surprised by your long-term glucose control. Your blood glucose control over time is measured by the A1C. Keeping postprandial glucose levels close to normal often can determine a good A1c outcome.

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