Oct 25, 2024 · Eat healthy, unsaturated fats (i.e. olive oil, nuts, olives, avocado, etc.). Stay hydrated (64oz of water per day) Don’ts: Eat dairy like yogurt, milk, or cheese. Eat refined carbs (bread, pasta, etc.). Drink alcohol or sugary drinks. Smoke (THC, nicotine, or otherwise). Gastric Sleeve Pre-Op Diet Part 2: 1 Week Before Surgery.