Short answer: Not always, but recommended
Fasting is not strictly required for most blood tests, but it does provide more accurate results. We recommend always having blood tests done in the morning between 08:00 and 10:00 and preferably fasting. For a number of specific tests, 12 hours of fasting is required.
Tests where fasting is required or strongly recommended
Fasting is essential for reliable results with these tests
Glucose (Blood Sugar)
12 hours fasting required
Fasting glucose is essential for diagnosing diabetes or pre-diabetes
Lipid Panel (Cholesterol, Triglycerides, LDL, HDL)
12 hours fasting required
Triglycerides and LDL cholesterol are strongly influenced by food intake
Homocysteine
12 hours fasting required
Important for cardiovascular disease and vitamin B status
Insulin
12 hours fasting required
For a reliable measurement of insulin levels
HOMA IR (Insulin Resistance)
12 hours fasting required
Measures how well your body handles sugar and insulin
Iron & Ferritin
Fasting strongly recommended
Iron levels fluctuate with food intake; fasting provides the most reliable picture
Bone Enzyme (BAP Osteoporosis)
12 hours fasting required
For research into bone density and osteoporosis
Vitamin B12 & Folic Acid
Fasting recommended
Supplements and food can temporarily influence levels
Cortisol (Stress Hormone)
Test before 10:00 AM
Not fasting, but early in the day for best results
Fasting: what's allowed and what's not?
Follow these guidelines for optimal test results
This is allowed
Drinking water
Unlimited water is always allowed and encouraged
Light breakfast (non-fasting tests)
Maximum 2 slices of whole wheat bread with lean topping, no butter
Taking medication
Continue your medication unless your doctor has advised otherwise
This is not allowed
Coffee and tea with milk/sugar
Only water is allowed during the fasting period
Dairy products
Milk, yogurt, cheese can affect test results
Fried and fatty foods
Can disrupt lipid values and other parameters
Alcohol
Avoid alcohol 24 hours before the test
Unsure about your preparation?
If you're unsure whether your test needs to be fasting, or have questions about medication, please contact us. We're happy to help you with the right preparation.
Contact us via our contact page for personal advice.Ready for your blood test?
Now that you know how to prepare, you can order your blood test.
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