Fasting Before a Medical Checkup: What You Should Know?

For a long time, fasting has been a way to detox and purge the system of toxic substances. It is a little extra something we do that improves our health. Fasting is encouraged by health practitioners because it promotes blood sugar control, reduces inflammation, aids weight loss and increases growth hormone secretion that aids metabolism, among other things. But did you know that you should also fast before going for a medical checkup?


But why would you need to fast before getting a checkup at a medical centre? The answer lies in the effect food has on your body or more accurately, on your blood. When you eat, the nutrients contained in your food are absorbed, after digestion, into the bloodstream where they increase or decrease the levels of some substances in the blood. These substances include blood sugar, cholesterol, enzymes, and some minerals. Some blood tests involve the measurement of these substances. These measurements are then used to make a diagnosis. Eating within a few hours before these tests may cause a temporary change in the level of these measured substances which, in turn, will give different results; this can lead to an inaccurate diagnosis. Fasting, therefore, ensures more accurate results.

You generally shouldn’t eat for up to eight hours before blood tests, but some require longer hours of fasting. Fortunately, the hours you spend sleeping are considered a part of your fasting period so you can fix your appointment as early in the day as possible. Traditional food isn’t the only thing you should stay away from during your fast period; there are other consumables that can alter the outcome of these tests.

Alcohol is one of such and should be avoided when doing some certain body checkups. Tests that assess liver health or Triglyceride levels are affected by alcohol which could remain in your system, in trace amounts, for several days after consumption. Alcohol also raises your cholesterol levels, indulging before a blood test will definitely cause a change in readings. Alcohol should be avoided at least 24 hours before blood tests, but the professional opinion of your physician should be sought first.

Coffee should also be avoided. Coffee may temporarily increase your blood pressure. This may give the appearance of high cholesterol, stress or excessive salt, and false blood pressure readings, which in this case would lead to the wrong diagnosis.

Sweets and chewing gum introduce sugar into the blood in the form of glucose, at this point there is an increase in glucose levels in your blood. When this happens, your body works to process that glucose into energy and transport it to your cells. To do this, your pancreas produces insulin. The end result is a drop in glucose levels in your body. This rise and drop can cause inaccurate reading during a blood test for sugar levels.

What you can consume within this fasting period is water; and lots of it. Water hydrates your body, making your blood vessels easier to find and access. Water helps with the transport of oxygen around the body through your blood and also helps maintain blood pressure. Although fasting is required for some checkups, it may not be a prerequisite to all checkups in your health screening package. Some checkups only require you cut back on certain foods or avoid certain activities. The ones that require total abstinence from food include Blood sugar test, Liver function test, Cholesterol test, Triglyceride level test, High-density lipoprotein (HDL) level test, etc.

While you should always talk to your physician about the terms of your fast or whether you should fast at all—like in cases of those that suffer from diabetes, you can use this as a checklist of some sort for consumables you should avoid prior to your test. So if you haven’t had a medical checkup in a long while, now may be a good time to use that body checkup promotion at your healthcare medical centre.