Diet & Fasting

What to Eat and Avoid Before a PET-CT Scan: Diet & Diabetic Guidelines

By Clinical Dietetics Team • 2026-08-09 • 4 min read

Your diet in the 24 hours prior to an 18F-FDG PET-CT scan directly dictates the clarity of your diagnostic images.

Pre-Scan Diet Rules:

24 Hours Before: Low-carb, high-protein diet. 6 Hours Before: Strict Nil-by-Mouth except plain water. No Chewing Gum or Mints.