Fasting Isn't Normally Necessary
Standard urinalysis does not require any preparation before testing. The standard test screens the urine sample for infections, pregnancy, metabolic disorders and kidney disorders. Urinalysis can detect abnormal levels of protein, glucose, red and white blood cells, bacteria and bilirubin in the urine.
Some Tests Require Fasting
In some cases, the doctor might order a battery of tests in conjunction with urinalysis. For example, patients who are ordered to take a fasting blood glucose test or a cholesterol blood test will be ordered to stop eating and drinking after midnight. In these instances, they must fast before providing urine specimens.
Unless otherwise directed by your doctor, it is unnecessary to fast before a urine analysis. According to the Mayo Clinic, patients may drink and eat regularly before being tested. However, it is necessary to provide the doctor or laboratory personnel with a list of medication and/or supplements that are being consumed, as these could affect test results.