Patients who undergo sleeve gastrectomy pass through three dietary stages after surgery:
Stage one: The First Month Diet
The purpose of this stage is to protect the internal staple line and allow the stomach to heal completely.
Stage Two: The Weight-Loss Phase
This stage focuses on healthy eating habits that support effective weight loss during the first months after surgery.
Stage Three: The Post-Ideal Weight Lifestyle
This stage represents a long-term balanced lifestyle aimed at maintaining weight loss and preventing weight regain.
Below is a detailed explanation of each phase:
Stage One: The First Month Diet After Sleeve Gastrectomy
Week 1
Patients should consume clear liquids only, including:
- Packaged fruit juices (any flavor).
- Clear soups such as chicken broth or meat broth
- Warm herbal drinks such as: Anise, Mint, Linden, Cinnamon, Caraway and Clove
Sugar may be added according to preference.
On days 6 and 7, the following may be added: Milk pudding, Jelly and/or Lentil soup
Liquids should remain the main component of the diet.
Week 2
Food should be mashed thoroughly using a fork, then eaten slowly in small quantities.
Use a small teaspoon and consume 3–5 teaspoons per meal, slowly and carefully.
Allowed foods include:
- Mashed potatoes
- Mashed zucchini
- Mashed sweet potatoes
- White cheese
- Cottage cheese
- Boiled eggs (mashed)
- Fried eggs
warm herbal drinks may continue.
Diet sweeteners may be used, up to two packets daily.
Week 3
The following foods may be introduced:
- Eggs
- White cheese
- Cooked or raw green vegetables such as: Zucchini, Okra, Peas, Spinach and Green beans
Warm liquids may still be consumed. Small amounts of oil or butter are allowed, but deep-fried foods should be avoided.
Week 4
Proteins are gradually introduced, including:
Meat, Poultry, Fish, Shrimp, Tuna, Minced, meat, and Chicken liver
You should begin with very small quantities, chew thoroughly, and avoid extremely hot foods.
Important Warnings During the First Month
Failure to follow the first-month diet plan may lead to serious complications.
During the first month patients must avoid:
- Smoking
- NSAIDs
- Alcohol
Patients should follow the diet instructions exactly.
The stomach staple line is still healing and can only tolerate the foods listed above.
Consuming carbohydrates such as bread, rice, pasta, or beans during the first two months may lead to dangerous complications.
Patients should drink 12–15 cups of fluids daily during the first year to prevent: Dehydration, Dizziness, Headache, and Blood clots
Urine color should remain light and clear, indicating proper hydration.
Stage Two: Weight Loss Diet After Sleeve Gastrectomy
This phase usually lasts 4–8 months after surgery.
Two dietary approaches may be followed depending on the patient’s metabolism and lifestyle.
Your surgeon will help determine which approach is most suitable during follow-up visits.
Option One: Strict Post-Sleeve Diet (80–100% Excess Weight Loss)
Relying on surgery alone is not enough to achieve an ideal weight.
Long-term success requires changing eating habits and following a healthy diet.
This diet is particularly recommended for:
- Women
- Older patients
- Patients with hypothyroidism
- Individuals with slower metabolism
Diet Characteristics
The diet should be High protein, Moderate fat, and Low carbohydrates
This approach typically results in 80–100% excess weight loss within 8–12 months.
These recommendations are based on guidelines from the American Society for Metabolic and Bariatric Surgery (ASMBS).
Foods to Avoid:
Rice, Pasta, Bread, Potatoes, Sweet potatoes, Lentils, Beans, Biscuits, fruits and fruit juices, Oats, Corn, Soy, Chia seeds, soft drinks and soda, desserts, Milk, Processed cheese, Peanuts, Almonds, Pistachios, Cashews, Sunflower seeds, Mayonnaise, Ketchup, Mustard, and Garlic sauce
Processed meat should also be avoided, including Sausages and Burgers.
These often contain soy, starch, and fillers that slow weight loss.
Allowed Foods
Protein Sources: Meat, Chicken, Fish, seafood, Tuna, Shrimp, Squid, Eggs …etc.
Ground meat, steak, and tender cuts are recommended because they are easier to swallow.
Boiled eggs may also be eaten as snacks between meals.
Vegetables: Any cooked vegetables are allowed, including:
Molokhia, Zucchini, Green beans, Okra, Peas, AND Spinach
Vegetables may be cooked normally using oil or butter.
Leafy vegetables are encouraged such as:
Arugula, Parsley, Celery, Dill, Green pepper, Broccoli
Eating one bunch of arugulas daily is recommended to help prevent constipation and provide essential minerals.
Meal Guidelines
There is no fixed quantity of food.
Patients should:
- Eating when hungry
- Stop immediately when full
- Chew food thoroughly
Example Daily Plan
Breakfast / Dinner
- Boiled or fried eggs
- White cheese
- Arugula or green pepper
Lunch
- Meat, chicken, or fish
- Cooked vegetables such as zucchini, spinach, molokhia, green beans, or okra
Snacks
- Eggs
- Tuna
- Meatballs
- Whey protein
- Mushrooms
- Green pepper with white cheese
- Herbal drinks with diet sweetener
Macronutrient Distribution
Daily intake should consist of approximately:
- 70% protein
- 20% fat
- 10% carbohydrates
Total daily calories should remain around 700 calories per day.
Option Two: Moderate Post-Sleeve Diet (40–60% Excess Weight Loss)
This diet is more suitable for:
- Men
- Patients with muscle mass above 35%
However, this approach usually results in a maximum weight loss of 60% of the excess weight loss.
The risk of weight regain within five years may reach 30%.
Average Weight Loss
About 2–3 kg per month.
Diet Composition
- 35% protein
- 35% healthy fats
- 30% carbohydrates
Daily calorie intake should not exceed 800 calories.
Typical daily intake includes:
- 50 g protein (about 200 g meat)
- 50 g carbohydrates
- 10–20 g fat
Patients should eat protein first, followed by vegetables, and carbohydrates last.
Maximum daily carbs intake should not exceed:
Two slices of diet toast, ¼ loaf of traditional bread or 3 teaspoons of rice
Fruit may be eaten twice weekly, excluding high-calorie fruits such as:
Mango, Grapes, Figs, and Dates
Intermittent fasting 12–16 hours daily may also improve results.
This diet is not recommended for women, elderly patients, or those with thyroid disorders.
If weight loss stops or weight increases, the patient should return to the stricter diet plan.
Phase Three: Long-Term Lifestyle After Reaching the Ideal Weight
This stage begins once BMI is below 30.
The goal is to maintain weight loss and prevent regain.
Guidelines include:
- Carbohydrates are allowed up to twice daily
- Prefer only one carbohydrate type per meal
- Fruit and milk allowed twice weekly
- Nuts allowed occasionally during holidays or summer, no more than once every 2–3 months
The following should be avoided permanently:
White bread, Oats, Popcorn, Soda, and Carbonated drinks
These foods may contribute to gastric sleeve dilation.
desserts may be consumed once monthly.
Protein and vegetables may be eaten freely.
Sugar and honey should be avoided.
Diet sweeteners may be used up to two packets daily.
