PET-CT 3-gram Carbohydrate Test Diet
Important: Follow this diet only if you’ve been instructed to follow it. Not all PET-CT scans require this diet. Always follow the instructions you were given for how to prepare for your specific test.
Why do I need to follow this diet?
Even small amounts of carbohydrate can affect the test. If you do not follow these instructions, the results of your PET-CT scan may not be accurate, and your appointment could be cancelled or rescheduled.
Contact the imaging department where your appointment is scheduled if you cannot follow this diet because:
- You have food allergies.
- You have dietary restrictions.
- You have difficulty chewing or swallowing.
How do I prepare for my appointment?
- Start this diet 36 hours before your PET-CT scan appointment.
- Eat and drink only the items listed under “What can I eat and drink?”
- Do not eat or drink items listed under “What foods and drinks do I avoid?”
- Check the nutrition facts label on foods and drinks. Choose items with less than 1 g of carbohydrate per serving.
- If you are not sure if a food, drink, supplement, or medicine is OK to have, contact the imaging department where your appointment is scheduled.
What can I eat and drink?
Only eat and drink the items listed below.
Meat and protein
Choose plain meat and protein foods. Prepare and season them using only the other foods listed here. Avoid products with added fillers, breading, sauces, or marinades.
- meat, such as beef, pork, lamb or game
- poultry
- fish and seafood
- eggs
Dairy
- hard cheeses with less than 1 g of carbohydrate per 30 g serving
Fats and oils
- butter
- margarine
- vegetable oils
Drinks
- water
- black coffee
- tea without milk or sugar
- diet soft drinks or other diet drinks with 0 g of carbohydrates
Sweeteners
Condiments
- salt
- pepper
- single herbs and spices
- white vinegar
- plain yellow mustard
What foods and drinks do I avoid?
Do not eat or drink the items listed below, or your appointment may be cancelled or rescheduled.
Meat and protein with added ingredients
- sausage
- deli meats
- sweetened ham or bacon
- breaded meats
- nuts
- dried beans
- peas
- lentils
- tofu
- seitan
Dairy
- milk
- yogurt
- cream cheese
- ice cream
- processed cheese
- plant-based beverages such as soy, oat, rice, or coconut beverages
- hard cheese with more than 1 g of carbohydrate per 30 g serving
Fats and oils
Fruits and vegetables
- all fruits
- all vegetables
- fruit juice
- vegetables
Grains and starches
- bread
- rice
- pasta
- cereal
- granola bars
- crackers
- cookies
- pastries
- cake
- all other grain products
Candies and sweets
- candy
- gum
- lozenges
- mints
- cough drops
- chocolate
Drinks
- alcoholic drinks
- regular soft drinks
- sports drinks
- lattes, cappuccinos, or other specialty coffees with milk or syrup
- hot chocolate
Sweeteners
- sugar
- dextrose (glucose)
- fructose
- sugar alcohols such as xylitol, sorbitol, erythritol, and mannitol
- sucralose
- stevia
- any sweetener not listed under “What can I eat and drink?”
Condiments
- mayonnaise
- ketchup
- sauces
- honey
- jam and jelly
- maple butter and apple butter
- salad dressings
- pickled foods
- balsamic vinegar and flavoured vinegars
- flavoured mustard
- seasoning mixes
- any condiment not listed under “What can I eat and drink?”
Supplements
- nutrition supplements with sugar or sweeteners
- vitamins with sugar or sweeteners
Medicines
- medicines with sugar or sweeteners, unless your healthcare team tells you otherwise
Questions about this test?
If you’re not sure if a food, drink, supplement, or medicine is OK to have on this diet, contact the imaging department where your appointment is scheduled.
To see this information online and learn more, visit MyHealth.Alberta.ca/health/aftercareinformation/pages/conditions.aspx?hwid=custom.ab_di_pt_3g_cho_test_diet_inst
For 24/7 nurse advice and general health information call Health Link at 811.
Current as of: August 24, 2026
Co-Author: Diagnostic Imaging, Alberta Health Services
Co-Author: Nutrition Services, Alberta Health Services
This material is not a substitute for the advice of a qualified health professional. This material is intended for general information only and is provided on an "as is", "where is" basis. Although reasonable efforts were made to confirm the accuracy of the information, Alberta Health Services does not make any representation or warranty, express, implied or statutory, as to the accuracy, reliability, completeness, applicability or fitness for a particular purpose of such information. Alberta Health Services expressly disclaims all liability for the use of these materials, and for any claims, actions, demands or suits arising from such use.
