Blood pressure reading affected by eating
When you check your blood pressure, or have it measured by a nurse or doctor, it's important to sit quietly for a few minutes beforehand. Not eating for two to three hours is another way to help you get the most accurate reading possible, according to a comprehensive study by Australian researchers.
They asked 38 volunteers to fast overnight, then come to a clinic for a series of blood pressure measurements. Once the "baseline" pressure had been measured, the volunteers ate a breakfast consisting of toast, margarine, jam, and water. As soon as they were finished eating, the researchers checked their blood pressure again, and then every 15 minutes for two hours. Blood pressure went up immediately after the meal, but then it began to fall, reaching a low point about 45 minutes after the meal and gradually climbing back to the pre-meal level over the next 90 minutes or so. For systolic pressure (the top number of a blood pressure reading), the low point was an average of 3 points below the baseline pressure, while diastolic pressure (the bottom number) fell an average of 4 points (American Journal of Clinical Nutrition, August 2009).
To continue reading this article, you must log in.
Subscribe to Harvard Health Online for immediate access to health news and information from Harvard Medical School.
- Research health conditions
- Check your symptoms
- Prepare for a doctor's visit or test
- Find the best treatments and procedures for you
- Explore options for better nutrition and exercise
I'd like to receive access to Harvard Health Online for only $4.99 a month.Sign Me Up
Already a member? Login ».
As a service to our readers, Harvard Health Publishing provides access to our library of archived content. Please note the date of last review or update on all articles.
No content on this site, regardless of date, should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician.