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Fasting Instructions

Too often people have had to reschedule a medical lab test because they did not properly fast beforehand. Certain tests require fasting because nutrients in food and drinks can distort the test results. For instance, eating a sugary snack before a blood test results in an unusually high blood sugar count. The test needs to be performed on a specimen from a body in its normal state.

Follow these fasting instructions:

  • For blood tests, do not eat or drink for 8+ hours before visiting the laboratory
  • For lipid tests, do not eat or drink for 12 hours before visiting the laboratory
  • It is okay to drink water, but not coffee, juice or tea
  • Do not smoke during the fasting period
  • Do not exercise during the fasting period, as this can affect the results
  • Avoid chewing gum, which can affect your test results
  • After the test is over, you are free to resume your normal routine

When to Start Fasting

The Salinas Valley Health Clinics laboratory hours are 6:30am to 3:00pm Monday through Friday. Many people begin fasting the night before so they can sleep through the fasting period. Because of this, the hours between 7:00am and 10:00am are the lab’s busiest. If you are able to wait, arriving after 10:00am may result in a shorter visit.