If you’re planning on having gastric sleeve surgery, you’re probably looking forward to your new body, and learning how to eat in a whole new way. Preparing for your life after gastric sleeve surgery will be exciting, but challenging, too.

The diet you’ll be required to follow both before and after surgery is very specific and geared toward aiding recovery and avoiding complications. As time progresses, your diet will shift toward helping you acquire healthy eating habits, so you can continue to lose weight and, ultimately, maintain a healthy weight for life.

A main, presurgery dietary goal is shrinking your liver. If you’re obese, your liver most likely has an accumulation of fat cells both in and around it. This makes it larger than it should be. Your liver is located right next to your stomach. A too-large liver makes gastric sleeve surgery harder for your doctor to do, and more dangerous for you to have done.

To prepare for the procedure, you’ll be given a specific diet to follow, beginning two weeks before your scheduled surgery date. It’s a strict diet that reduces calories as well as carbohydrates, such as sweets, potatoes, and pasta. You will eat primarily lean protein, vegetables, and low- or no-calorie fluids. Your doctor may give you a caloric goal to stick to daily.

Two days prior to surgery, you will switch to a clear, liquid diet. This may include one no-sugar protein shake daily, in addition to broth, water, decaffeinated coffee or tea, Jell-O, and sugar-free popsicles. Caffeinated and carbonated beverages should be avoided.

For the first week after the procedure, you’ll continue with the same clear liquid diet you followed in the days leading up to surgery. This will help to avoid postoperative complications, including bowel obstruction, gastric leakage, diarrhea, constipation, and dehydration. Your body needs time to heal, and this regimen will help with that goal. Tips to keep in mind include:

  • Make sure to drink plenty of clear liquids. If you have trouble remaining hydrated, talk to your doctor about electrolyte drinks to try, such as low-calorie Gatorade.
  • Don’t drink anything with sugar. Sugar can contribute to dumping syndrome, a complication caused by too much sugar entering the small intestine quickly. This results in severe nausea, fatigue, diarrhea, and even vomiting. Sugar is also full of empty calories. It should be avoided now and minimized in the long term.
  • Caffeine may contribute to acid reflux and dehydration, and should also be avoided.
  • Carbonated beverages, including those with sugar, no-calorie options, and seltzer, can all contribute to gas and bloating. These should all be avoided postoperatively and possibly even long term.

During the second week after surgery, you will graduate to a full-liquid diet. Options include:

  • no-sugar nutrition shakes, such as Ensure Light
  • instant breakfast drinks
  • shakes made with protein powder
  • thin broth and cream-based soups with no chunks — soft soup noodles are ok in very small amounts
  • unsweetened milk
  • sugar-free, nonfat pudding
  • sugar-free, nonfat frozen yogurt, ice cream, and sorbet
  • nonfat plain Greek yogurt
  • fruit juices with no pulp, diluted with water
  • thinned, hot cereal, such as Cream of Wheat, or oatmeal

During this period, you may feel your appetite increase. That is perfectly natural, but not a reason to eat solid food. Your system is still unable to handle solids. Vomiting and other complications can result. Filling up on liquids and avoiding sugar and fat will help prepare you for the next stage of your diet. Carbonated beverages and caffeine should still be avoided.

During week three, you can add soft, pureed foods to your diet. Make sure to eat slowly and chew food thoroughly — at least 25 times, if possible. Any low-fat, sugar-free food that you can puree, including lean protein sources and nonfibrous vegetables, are acceptable. It’s important to start increasing your protein intake. If you don’t like the taste of pureed lean protein sources, continue to drink no-sugar protein shakes or eat eggs daily. Foods to eat include:

  • jarred baby food
  • silken tofu
  • cooked, pureed white fish
  • soft-scrambled or soft-boiled eggs
  • soup
  • cottage cheese
  • canned fruit in juice
  • mashed bananas or very ripe mango
  • hummus
  • pureed or mashed avocado
  • plain Greek yogurt

Continue to avoid chunked and solid foods, as well as caffeine, during this time. You should also stick to bland food with mild or no seasoning. Spices may contribute to heartburn.

Now that you’re one month post-surgery, you can start adding solid foods to your diet. This is the time to put your new healthy-eating skills into action, full force. Sugar and fat, including high-fat dairy, should still be avoided, as should hard-to-digest foods such as steak, fibrous vegetables, and nuts. Other foods to avoid include pasta, white potatoes, and other high-carb options. Caffeinated beverages can usually be reintroduced, in moderation, at this time. Foods you can add to your list include:

  • well-cooked chicken and fish
  • well-cooked vegetables
  • sweet potatoes
  • low-fat cheese
  • fruit
  • low-sugar cereal

Now that you can eat solid food safely, it’s time to put your new-normal eating plan into long-term effect. Keep the emphasis on lean protein and vegetables, introducing one food at a time so that you can monitor your body’s reaction. Foods you should avoid entirely, or only eat on occasion from this point forward, include sugary sweets and soda. All other foods can be incorporated back in unless they trigger symptoms.

Choose your foods wisely, picking nutrient-dense options, and avoid empty calories. Eating three small meals a day, with minimal snacks, may help you stick to your plan. Also make sure to always remain hydrated.

Post-surgical recovery tips that can help you stay on track include:

  • Use a blender or food processor to puree foods.
  • Learn to recognize the difference between hunger (physical) and appetite (mental/emotional).
  • Don’t overeat — your stomach will stretch in time and stabilize in size.
  • Chew slowly, and eat slowly.
  • Avoid non-nutrient calories.
  • Avoid concentrated sugars.
  • Avoid trans fats and fried, processed, and fast foods.
  • Avoid dehydration by sipping water or low-calorie versions of Gatorade.
  • Don’t eat and drink at the same time.
  • Talk to your doctor about bariatric vitamins and supplements to decide what you should take, and when.
  • Build movement into your life. Start with walking, and explore other exercises that you enjoy, such as swimming, dancing, and yoga.
  • Avoid alcohol. Gastric sleeve surgery and other types of bariatric surgeries may increase, and quicken, alcohol’s effects.
  • Avoid nonsteroidal anti-inflammatory drugs (NSAIDs), such as Ibuprofen, aspirin, and naproxen. These types of over-the-counter pain medications may reduce your stomach’s natural, protective coating.

It’s important to follow the eating plan your doctor provides for you both before and after gastric sleeve surgery. The foods you are allowed are designed to help your body recover, and also to pave the way toward a healthy eating lifestyle for life. Exercise is also a vitally important element.