Pre-Op Bariatric Diet — Complete Guide
The official pre-operative bariatric diet from Dr. Alejandro López. Designed to shrink your liver, reduce surgical risk, and prepare your body for safe surgery.
Why the pre-op diet matters
Shrink the liver
Reduces fatty liver size, making laparoscopic surgery safer.
Lower lipids
Reduces cholesterol and triglycerides in blood.
Less risk
Lower surgical and anesthesia risk.
Prevent complications
Improves recovery outcomes.
🔵 Phase 1 — Pre-Op Diet
General instructions
- ✓ No smoking
- ✓ Stay well hydrated (minimum 2 liters of water daily / ~68 oz)
🥤 Protein requirements
Minimum 60-90 grams of protein per day.
Use protein shakes or powder. Each portion should contain:
- ✓ ≥20g protein
- ✓ <6g carbohydrates
- ✓ <3g fat
Mix preferably with water only.
🥗 Sample menu
- 🌅 Breakfast: 1 protein shake
- 🥗 Lunch: 1 protein shake
- 🍽️ Dinner: Salad with lean protein (chicken, fish, egg) and fat-free dressing
- 🌙 Evening snack: 1 protein shake (if needed)
Low-carb vegetables allowed if hungry: Lettuce · Spinach · Cucumber · Zucchini
❌ Avoid completely
Sugar · Bread, rice, pasta, tortillas · Juice · Alcohol · Fried or high-fat food
🔵 Phase 2 — Clear Liquid Diet
After the pre-op diet, immediately before surgery.
✅ Allowed
- • Water
- • Sugar-free flavored water
- • Fat-free broth (chicken, beef, fish)
- • Sugar-free gelatin
- • Tea (no sugar)
- • Sugar-free water popsicles
- • 1-3 whey protein shakes daily (with water)
❌ Not allowed
- • Milk or dairy products
- • Creamy drinks
📊 Pre-Op Diet Duration by BMI
⚠ IMPORTANT: Not following the diet properly can result in surgery cancellation.
Questions about your pre-op diet?
If you are approaching your bariatric surgery date, message our nutritionist directly. Your protocol depends on your case.