Diet: Gastric Sleeve Vs. Bypass
Your gastric sleeve vs gastric bypass diet transition is virtually identical:
- 2+ Weeks Before – Practice your post-surgery diet
- 2 Weeks Before – High protein, low sugar, low carbs
- 1 Week Before – Stop or change some medications
- 2 Days Before – Clear liquids only
- Midnight Before Surgery – Nothing to eat or drink
- In Hospital to 7 Days After Surgery (Varies by Surgeon) – Sugar-free clear liquids only
- Day 1 to Week 2 After Surgery (Varies by Surgeon) – Add thicker drinks & smooth foods
- Day 2 to Week 3 After Surgery (Varies by Surgeon) – Slowly test pureed foods & soft solid foods
- Day 3 to Weeks 4+ After Surgery (Varies by Surgeon) – Slowly test solid food
The foods you’ll need to avoid are also very similar, although gastric bypass has some additional diet-related aspects to consider.
Diet issues unique to gastric bypass include:
- Avoid foods that are likely to cause dumping, including sugar, unnecessary fat, or refined carbohydrates (although you should avoid these after gastric sleeve as well, they won’t cause dumping for sleeve patients).
- Patients who undergo the bypass procedure are at especially high risk of developing Alcohol Use Disorder (AUD) (7) (8) (9)
Following are dietary guidelines for both gastric bypass and gastric sleeve:
- Test one food at a time to make sure you can tolerate it
- Eat proteins first, in solid form (e.g., not protein shakes)
- Eat healthy “whole” foods
- Avoid processed foods
- Avoid sugary foods or drinks
- Eat slowly and chew thoroughly
- No starchy foods like rice, bread, and pasta
- Avoid any food that is difficult to digest (may be able to tolerate over time), such as:
- Fibrous vegetables like broccoli, celery, and corn
- Skin of any meat
- Tough meats
- Avoid whole milk products
- Drink 64+ oz (2+ liters) of fluids spread throughout the day
- No drinking 30 minutes before or after meals (other than gastric balloon)
- Alcohol only in moderation
See the following pages for more information:
Vitamins: Gastric Sleeve Vs Bypass
Due to gastric bypass surgery’s higher levels of malabsorption, gastric bypass patients:
- Are much more likely than gastric sleeve patients to require Thiamin (Vitamin B1) supplementation
- Must be more vigilant in confirming no vitamin or mineral deficiencies
The rest of the vitamin requirements are usually the same for gastric bypass and gastric sleeve, including:
- Daily multivitamin
- 1 to 2 per day, forever
- Chewable or liquid versions are best (instead of tablets)
- Take with food (except dairy) to maximize absorption
- At least 200% of the Recommended Dietary Allowance (RDA) of iron, folic acid, thiamine, copper, selenium and zinc
- Daily calcium supplement, in the form of calcium citrate
- Must be calcium citrate (NOT other forms of calcium)
- 1000-1500 mg. daily, forever
- Chewable and liquid versions are best (instead of tablets)
- Try to find one that includes Vitamin D
- Take 2 hours apart from Iron supplements (or Multivitamin that contains Iron) to maximize absorption
For either procedure, you may be required to take one or more of the following depending on your vitamin levels:
- Folate (folic acid)
- Thiamin (Vitamin B1)
- Vitamin D
Exercise: Gastric Sleeve Vs Gastric Bypass
After you’ve full recovered from surgery (4 to 6 weeks), recommended exercise is the same for both gastric bypass and gastric sleeve patients: 2.5 hours per week, spread out over 2 to 4 days.
Following this regimen will cause you to:
- Lose more weight
- Be more physically and mentally healthy
Learn more on our Exercise After Weight Loss Surgery page.
Hunger: Gastric Bypass Vs Sleeve
After gastric sleeve, you are likely to feel less hungry as a result of 80% of your stomach being removed. This is not the case after gastric bypass because all of the stomach remains in place (although the stomach will be separated into two parts).
Here’s why gastric sleeve reduces hunger:
When your stomach is empty, it secretes a hormone called ghrelin into your bloodstream which causes your brain to generate hunger impulses. After you eat, the amount of secreted ghrelin drops then slowly rises until your next meal. Since your stomach will be significantly smaller after gastric sleeve surgery, the amount of ghrelin the stomach secretes – and your resulting feelings of hunger – may also go down.
Food Addiction: Gastric Bypass Vs Sleeve
Regardless of which procedure you have, food addiction could be a problem.
Our bodies secrete certain hormones, like ghrelin mentioned above, that tell us when we’re hungry and full, but hyperpalatable food (like junk food) may be overriding those hormone signals by overstimulating our reward centers, much like our bodies and brains react to an addictive drug.
You may have a bona fide food addiction if your desire for food takes priority over other parts of your life that you acknowledge to be more important, such as personal health, family, friends, work, your appearance, or avoiding obesity related health issues like hypertension, sleep apnea, or diabetes.
If left unchecked, food addiction can lead to obesity. For weight loss surgery patients, if not addressed prior to surgery, it can also lead to weight regain.
To find out if you may be suffering from food addiction, take our Food Addiction Quiz.
Relationships After Weight Loss
Significant weight loss after any type of bariatric surgery can lead to big changes with everyone around you.
While many of those changes are positive, some can also be extremely challenging and unexpected.
See our Relationships After Weight Loss Surgery page for important changes to prepare for.