Bariatric surgery, including gastric sleeve surgery, is a significant step toward weight loss and improved health for individuals with severe obesity. The success of this procedure hinges not only on the surgery itself but also on the patient's commitment to dietary changes before and after the operation. The pre-operative (pre-op) diet plays a crucial role in preparing the body for surgery, minimizing risks, and setting the stage for long-term weight management.
The Importance of a Pre-Op Diet
The pre-op diet for gastric sleeve surgery is not merely a suggestion but a vital component of the overall treatment plan. Registered dieticians James Miller and Whitney Stevens emphasize that neglecting the pre-op diet can lead to surgical complications, nutrient deficiencies, and suboptimal weight loss outcomes.
Key Benefits of Following a Pre-Op Diet:
- Liver Shrinkage: One of the primary goals of the pre-op diet is to reduce the size of the liver. An enlarged liver, often associated with fatty liver disease in individuals with obesity, can obstruct the surgeon's access to the stomach, making the procedure more challenging and potentially increasing the risk of complications. Weight loss before surgery will shrink the size of the liver, allowing the surgeon to see the stomach better.
- Reduced Abdominal Fat: The pre-op diet aids in reducing abdominal fat, further improving surgical access and safety.
- Stomach Wall Thinning: The diet can contribute to thinning the stomach wall, simplifying the stapling portion of the surgery.
- Shorter Operating Room Time: Some studies have shown that pre-operative weight loss can shorten the duration of the surgery.
- Reduced Complication Risks: By lowering the Body Mass Index (BMI) through pre-operative weight loss, the risk of developing complications is reduced.
- Establishment of Healthy Habits: The pre-op diet serves as a training ground for adopting the new eating habits that will be essential for long-term success after surgery.
- Nutritional Preparation: A high-protein pre-op diet supports wound healing and prepares the body for the metabolic demands of surgery and recovery.
Phases of the Pre-Op Diet
The pre-op diet typically spans several weeks, with specific guidelines for each phase. A common approach involves a two-phase plan:
Phase 1: General Dietary Changes (Approximately 4 Weeks Before Surgery)
This phase focuses on making gradual changes to eating habits to promote weight loss and overall health.
- Calorie Reduction: Reduce your daily calorie intake, especially from simple carbohydrates found in candy, soft drinks, bread, and pasta.
- Protein Maximization: Aim for at least 60-80 grams of protein per day. Lean sources such as chicken, fish, eggs, and low-fat dairy will help preserve muscle mass as you lose weight.
- Healthy Fats: Incorporate foods rich in healthy, unsaturated fats such as salmon, nuts, seeds, and olives. Limit unhealthy fats found in butter and oils.
- Hydration: Drink a minimum of 64 ounces of water per day. Avoid sugary drinks like sodas and alcohol. Other acceptable fluids include sugar-free, caffeine-free, and uncarbonated options like Crystal Light and decaf unsweetened tea.
- Food Logging: Keep a record of your food and liquid intake to increase self-awareness of eating habits and ensure adequate fueling of your body.
- Physical Activity: Increase your cardiopulmonary function and muscle strength prior to surgery.
Phase 2A: High-Protein Liquid Diet (Two Weeks Before Surgery)
This phase involves a stricter, high-protein, full-liquid diet to promote rapid weight loss and further shrink the liver.
Read also: The Hoxsey Diet
- Liquid Meals: Follow a Phase 2A meal plan consisting entirely of liquids. This diet helps to lose body fat while preserving muscle mass.
- Protein Shakes: Consume two high-protein, low-carbohydrate shakes per day. Shakes should contain at least 20 grams of protein and be limited to 10 grams of carbohydrates or less per serving.
- Limited Variety: Understand that variety will be limited during this phase, but remember it is only for a short period of time.
- Hydration: Continue to consume a minimum of 64 ounces of water per day, adhering to the guidelines for acceptable fluids.
- One Meal Per Day: Eat one meal per day following the pre-op diet meal guide.
- Snacks: Eat 1-2 snacks per day, limiting yourself to no more than 10g of carbs per snack (example: ½ cup fresh berries, ¼ cup nuts, or string cheese with 2-3 crackers).
Sample Meal Plans and Food Choices
During the pre-op diet, focus on lean protein sources, non-starchy vegetables, and limited amounts of starchy vegetables.
Recommended Protein Sources (4-6 oz per serving):
- Fish
- Chicken
- Turkey
- 2-3 large eggs
- ¾ cup liquid egg whites
- 93/7 ground meat
- Venison (deer)
- Extra firm tofu
Recommended Starchy Vegetables (Up to ½ cup per serving):
- Potatoes
- Sweet potatoes
- Corn
- Beans (not BBQ-style)
- Peas
Recommended Non-Starchy Vegetables (Unlimited):
- Carrots
- Leafy greens (spinach, lettuce, kale)
- Green Beans
- Peppers
- Tomatoes
- Asparagus
- Broccoli
- Cabbage
- Celery
- Radishes
- Eggplant
- Brussels sprouts
- Squash / zucchini
- Mushrooms
- Cucumbers
- Cauliflower
Protein Shake Options:
- Premier Protein®: 30 grams of protein per serving; 4-6 grams of carbohydrates per serving.
- Pure Protein® 100% Whey Protein Powder or Shakes: 30 grams of protein per serving; 6 grams of carbohydrates per serving.
- Fairlife® Nutrition Plan: 30 grams of protein per serving; 3-4 grams of carbohydrates per serving.
- Muscle Milk® (various options): 20-40 grams of protein per serving; 7 grams of carbohydrates per serving.
- Vital Proteins® Collagen Peptides: Unflavored: 20 grams of protein per serving; 0 grams of carbohydrates. Chocolate: 20 grams of protein per serving; 4 grams of carbohydrates.
Sample Meal Ideas:
- Dinner: 4-6 oz grilled chicken breast, ½ cup baked sweet potato, small salad of spinach, tomatoes, and shredded carrots with light drizzle of infused olive oil dressing (~2tsp).
- Snack: Celery with 1 Tbsp peanut butter, string cheese with ½ cup fresh berries.
The Day Before Surgery
- Liquid Diet: Consume only liquids the day before surgery. Do not eat any solid food.
- Hydration: Continue to consume a minimum of 64 ounces of water per day, following the guidelines for acceptable fluids.
The Day of Surgery
- Electrolyte Solution: About 4 hours before surgery, drink 12 ounces of Gatorade or another electrolyte solution to enhance recovery.
- NPO: After consuming the electrolyte solution, do not eat or drink anything other than a small sip of clear liquids to take medications.
Managing Hunger and Cravings
It is normal to experience hunger during the pre-op diet, especially during the liquid phase.
- Distinguish Between Physical and Head Hunger: Recognize the difference between true physical hunger and "head hunger," which is the desire to crunch or snack on certain foods.
- Manage Hunger: Accept that some hunger is expected and find ways to manage it.
- Expand Variety Within Limits: While variety is limited, explore different flavors and brands of acceptable liquid drinks.
Medications and Supplements
- Medication Review: Talk to your doctor about how to adjust medications, including insulin, during this low-calorie, low-carbohydrate diet phase.
- Hormonal Therapy: Discontinue all hormonal therapy (testosterone, birth control pills) one month before surgery to reduce the risk of blood clots. If you have implantable birth control or an IUD, you do not have to have this removed.
- Thyroid Medication: Thyroid medication should continue to be taken.
- Diet Medications: Discontinue phentermine, Ozempic®, or any other diet medication 2 weeks before surgery due to potential interactions with anesthesia.
- Herbal Supplements: Discontinue all herbal supplements other than vitamins two weeks before surgery.
- Bariatric Vitamins: Start taking bariatric vitamins at least two weeks before surgery.
- NSAIDs, Arthritis Drugs, and Blood Thinners: Certain medications, such as NSAIDs, arthritis drugs, herbal supplements, and blood thinners, may need to be stopped prior to surgery.
Lifestyle Changes
- Smoking Cessation: Smoking, vaping, dipping chewing tobacco, or any form of nicotine are strictly prohibited due to the increased risks of surgical complications. You will undergo nicotine testing for confirmation before surgery will be scheduled. You will be required to commit to avoiding nicotine completely after surgery as well, due to the increased risks of stomach ulcers.
- Alcohol Avoidance: Cut out alcohol consumption entirely.
- Caffeine Reduction: Wean off caffeine-containing drinks over these two weeks. You will need to avoid caffeine for the first two weeks after surgery (until the Soft Food Diet stage starts).
Potential Side Effects
Some individuals may experience side effects such as fatigue, headaches, and irritability during the pre-op diet. These symptoms are usually temporary and subside within a few days as the body adjusts to the lower calorie and carbohydrate intake.
Contraindications
The pre-op diet may not be suitable for everyone. Individuals with chronic kidney disease or renal failure should consult with their bariatric surgeon before starting the diet, as it can put stress on the kidneys.
The Post-Op Diet: Continuing the Journey
The pre-op diet is just the beginning of a lifelong commitment to healthy eating. The post-operative (post-op) diet is equally crucial for healing, preventing complications, and achieving long-term weight loss success. The post-op diet progresses through several stages, starting with clear liquids and gradually advancing to pureed foods, soft foods, and eventually solid foods.
Read also: Walnut Keto Guide
Stages of the Post-Op Diet:
- Clear Liquids: Immediately after surgery, your diet will consist only of clear liquids, such as water, broth, and sugar-free flavored drinks. Avoid carbonation, caffeine, and anything with added sugar.
- Full Liquids: During your second week, you’ll transition to foods like protein shakes, Greek yogurt, applesauce, cream of wheat, and sugar-free puddings.
- Pureed Foods: By the third week, you can begin eating scrambled eggs, ground meat, cooked vegetables, beans, and soft fruits.
- Soft Foods: In the fourth week, most patients can reintroduce solid foods. The focus should remain on lean protein, vegetables, and complex carbs.
Long-Term Dietary Guidelines:
Even after the first month, your eating habits will determine your success.
- Eat slowly, chew thoroughly, and stop when you feel satisfied.
- Stick to small portions.
- Prioritize protein.
- Limit your intake of processed foods and added sugars.
- Avoid fried foods, candy, nuts, seeds, whole dairy products, breads, pastas, and fibrous vegetables such as broccoli.
- Focus on lean protein, complex carbohydrates, and healthy fats.
Read also: Weight Loss with Low-FODMAP