For an entire day prior to a positron emission tomography scan, patients must eat foods high in protein and low in carbohydrates, according to Henry Ford Health System. Patients must also fast for six hours prior to the scan.
For breakfast on the day prior to the PET scan, patients may eat foods such as scrambled eggs, peanut butter, and bacon or sausage, suggests Henry Ford Health System. Patients may eat lunch foods such as sliced turkey or chicken, lettuce, cheese and cottage cheese. One slice of whole-wheat bread is acceptable with lunch. For dinner, patients can eat unbreaded meats, such as beef, pork, chicken or turkey. Other acceptable dinner foods include salad greens with dressing, green beans, sour cream and butter. Water and diet soft drinks are acceptable drinks throughout the day.
Prior to a PET scan, patients should avoid high-carbohydrate foods, such as cereals, pastas, dry beans, fruit and rice. They should also avoid foods high in sugar, including honey, desserts, candy, jellies and fruit juices, according to Cedars-Sinai.
A low-carbohydrate, high-protein diet helps the human body properly distribute radioactive glucose, which the scan examines, states the Henry Ford Health System. Prior to the scan, doctors provide patients with detailed preparation instructions that include dietary and exercise requirements, according to Mayo Clinic.