Can I eat before a urine test?

Quick Answer

There are no food or drink restrictions before most routine urine tests. However, your doctor may give specific instructions to fast or avoid certain foods if the urine test requires a first morning void or is checking for specific substances.

What Is a Urine Test?

A urine test, also called a urinalysis, checks a sample of your urine for various substances and factors. Doctors use urine tests to look for signs of a condition or disease. Urine tests can check for:

  • Protein, blood, or white blood cells, which can indicate an infection or kidney disease
  • Glucose, which can indicate diabetes
  • Ketones, which can indicate a metabolic condition
  • Bacteria or viruses causing a urinary tract infection
  • Blood in the urine, which can result from kidney stones, tumors, infection, or injury
  • Bilirubin, a pigment that can indicate liver problems
  • Crystals, which can form from abnormal mineral levels
  • Drugs or toxins
  • Pregnancy

Urine tests require collecting a urine sample in a special container. This is usually done at a doctor’s office or lab, but sometimes the doctor may ask you to collect the sample at home.

General Guidelines for Eating and Drinking Before a Routine Urine Test

For most routine urine tests, like a general urinalysis looking for infections, proteins, or glucose, you do not need to restrict your eating or drinking beforehand. In fact, eating normally can help provide an adequate urine sample. Dehydration can make it difficult to collect enough urine.

So for most urine tests, you can eat and drink normally before providing a sample. There are generally no fasting requirements.


In some cases, your doctor may ask you to follow specific instructions about eating, drinking, or fasting before a urine test. For example:

  • First morning urine: If the doctor needs a first morning void, you may be instructed to avoid going to the bathroom overnight and collect the first urine after waking up. This sample contains higher levels of many substances.
  • Fasting: You may be asked to avoid food for 8-12 hours before collecting a fasting urine sample. This could be to check glucose or protein levels when food intake is controlled.
  • Specific foods: If your urine is being tested for certain chemicals or toxins, you may need to avoid potential sources like poppy seeds, which can affect drug screens.
  • Medications: You may need to avoid certain medications that could impact the test.
  • Alcohol: You may be asked to avoid alcohol before a urine test.

In these cases, be sure to follow your doctor’s specific instructions on fasting or dietary restrictions when preparing for the urine test.

Tips for Eating and Drinking Before a Urine Test

Here are some general tips for eating and drinking before a routine urine test when you do not have specific fasting or dietary instructions:

  • Drink normal amounts of fluid in the 24 hours leading up to the test to avoid overly diluted or concentrated urine.
  • Avoid large amounts of fluid right before the test, which could make it harder to collect a sample.
  • Eat normally to avoid dehydration and provide an adequate sample.
  • Avoid alcohol in the 24 hours leading up to the test.
  • Don’t take non-prescribed medications or supplements that could impact the test results.
  • If fasting is required, drink plain water while avoiding all food, candy, gum, and other beverages.
  • Use a clean catch technique when collecting urine to avoid contamination.

Can You Drink Water Before a Urine Test?

Drinking normal amounts of water before a routine urine test is fine. Staying well-hydrated makes it easier to provide an adequate urine sample after arriving to the testing location.

Avoid drinking extremely large amounts of fluid right before the test, which could dilute the sample. But there is no need to dehydrate yourself. Drinking about 16 ounces (2 cups) in the two hours before the urine test is reasonable for most healthy adults.

Unless your doctor instructs otherwise, continue drinking normal amounts of water and other non-alcoholic, non-caffeinated beverages in the 24 hours leading up to your urine test.

Can You Drink Coffee Before a Urine Test?

Drinking coffee before a regular urine test is generally allowed, but should be avoided right before providing the urine sample. Caffeine is a mild diuretic, meaning it increases urine production. Consuming coffee or other caffeinated drinks within two hours of the urine test could make it harder to collect an adequate sample.

Caffeine will not directly interfere with routine urine test results. But if you drink coffee too close to the test, you may urinate more frequently and have a harder time providing enough urine. This could delay the collection process.

To be safe, avoid caffeinated beverages in the two hours before your urine test. Before that, normal caffeine intake from coffee, tea, soda, or energy drinks shouldn’t affect the test.

What You Can and Can’t Eat Before a Urine Test

For most routine urine tests, there are no dietary restrictions and you can eat normally. However, for urine tests checking for specific substances, your doctor may instruct you to avoid certain foods that could impact the results.

Foods to Avoid Before Specific Urine Tests

  • Poppy seeds: Avoid for drug tests, as they may cause a false positive result for opiate drugs.
  • Beef or lamb: May affect a urine porphyrins test.
  • Cruciferous vegetables: Broccoli, cabbage, kale and collards may affect a urine steroid test.
  • Glucose tablets: Avoid before a urine glucose if checking for diabetes.
  • High protein diet: May be restricted before a urine protein test.

Allowed Foods Before Urine Tests

Unless your doctor instructs you to fast or avoid specific foods, you can generally eat normally before a urine test. Some foods that are usually fine include:

  • Whole grains like whole wheat bread, oatmeal, brown rice
  • Fruits and vegetables besides cruciferous varieties
  • Lean protein like chicken, fish, eggs, or beans
  • Dairy products like milk, yogurt, cheese
  • Healthy fats like olive oil, avocados, nuts

Drink plenty of water and eat a balanced diet in the day leading up to your urine test.

Foods and Drinks to Avoid Before a Urine Drug Test

Urine drug tests check for the presence of illegal or prescription drugs. For accurate results, avoid:

  • Illegal drugs like marijuana, cocaine, or amphetamines
  • Narcotic pain medications without a prescription
  • Certain foods that may cause a false positive on drug tests:
    • Poppy seeds, which may show up as opioids like morphine or codeine
    • Coca leaves in tea, which may show up as cocaine
    • Hemp seeds and protein powder, which may show up as marijuana

Before a drug test, inform your doctor about any drugs or supplements you are taking, even if they are prescribed. Avoid illegal drug use which could lead to a positive result.

Can You Drink Alcohol Before a Urine Test?

It’s best to avoid drinking alcohol in the 24 hours before most urine tests. Alcohol and its byproducts can potentially affect urine test results. Alcohol also causes dehydration, making it difficult to collect an adequate urine sample.

Drinking alcohol shortly before a urine test can potentially lead to:

  • An inadequate urine sample due to dehydration
  • Elevated urine ketone levels
  • A positive urine ethanol test
  • Interference with tests results for glucose, proteins, etc.

Alcohol may also interact with medications you are taking, which could impact your test results. For accurate urine test results, avoid drinking alcohol for 24 hours beforehand.

Foods to Avoid Before a Urine Pregnancy Test

There are no specific dietary restrictions before taking a urine pregnancy test. Since these tests measure the presence of hCG hormone, your diet does not affect the accuracy of the results.

However, avoid drinking large amounts of fluid right before taking the test. This could dilute the hCG in your urine sample and make the test results harder to interpret. Eat and drink normally in the day leading up to the pregnancy test.

Can You Eat Before a Urine Culture?

A urine culture is a specific test that checks for the presence of bacteria in a urine sample. This test helps diagnose a urinary tract infection (UTI).

There are no dietary restrictions for a urine culture. Since this test checks for live bacteria, eating or fasting does not affect the accuracy of the results.

However, wipe properly before collecting a mid-stream urine sample for the culture. Women should not collect urine during their menstrual periods for an accurate UTI test result.

Food and Medications to Avoid Before a Urine 5-HIAA Test

A 5-HIAA urine test checks levels of 5-Hydroxyindoleacetic acid, a breakdown product of serotonin. It is used to look for carcinoid tumors that can secreting excess serotonin.

Certain foods and medications can affect 5-HIAA levels. Avoid the following before this test:

  • Bananas, pineapples, kiwi, plums, eggplant, avocados, nuts, and cough syrup
  • Acetaminophen (Tylenol), caffeine, and aspirin
  • Antibiotics
  • Monoamine oxidase (MAO) inhibitors

Check with your doctor about any other restricted foods or medications before a 5-HIAA urine test.


For most routine urine tests, you can eat and drink normally beforehand. Staying well-hydrated will help you provide an adequate sample. Avoid alcohol and caffeine directly before testing.

If your urine test requires fasting or avoiding certain foods, follow your doctor’s specific instructions. Make sure to inform them of any medications or supplements you take. This will help ensure you get accurate urine test results.

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