Post-Surgery Diet

After gastric bypass surgery it is important that your body receives the correct nutrition to help you recover. The post surgery diet is an important aspect of the recovery process.

It sometimes helps to think of your stomach as a sink with a plug hole. If you fill a sink slowly, the water will drain through but if you pour too much water into the sink at one time, the sink overflows. Post-surgery your stomach is similar to a sink: the plug hole is smaller than before and the amount you can put into it at one time has to reduce to help it drain.

To help your body adjust it is important that you separate eating and drinking. Drinking while you eat will allow you to eat more than you need as the liquid makes it easier for food to drain through the stomach. You should always stop drinking 15 minutes before a meal.

Post-Surgery Dieting

Patients post-surgery gastric bypass diet needs to be nutritious as meals are smaller than your body is accustomed to. A good balance of proteins and vitamins and a diet that is low in fats and carbohydrates will help you achieve and maintain your weight loss.

Your new stomach will only hold a small amount of food, but to achieve weight loss it is important this food is dense to keep you feeling full for longer. Eating high fat or consuming calorie dense drinks will make it more difficult for you to loose the weight you want and maintain the weight loss. A post-surgery diet should be rich in protein and vegetables and should contain no more than 15% carbohydrates.

Your post-surgery body may need extra nutrition than your smaller meals can provide. It is likely your doctor will recommend a course of vitamins and minerals to prevent malnutrition following surgery.

Post-surgery, patients are at risk of dumping syndrome and nutritionists recommend avoiding certain foods, such as excess sugar to prevent dumping. For more information on how to eat to prevent dumping, see here.

Most importantly after surgery, you should begin to enjoy food again. Weight loss will happen, for some patients it happens quickly and for some it is slower but if you follow the guidelines, you will achieve the slimmer figure you want. Eating with supportive family and friends can help keep you on track and allow you to socialize without worrying about having a negative effect on the results of surgery. 


Dumping syndrome occurs after gastric bypass surgery due to the change in the way the stomach processes food. Changing dietary habits is necessary after weight loss surgery to maintain a lower weight but changing the way you eat can also prevent dumping syndrome.


  • Eat 4-6 small meals – eating small amounts regularly helps the digestive system process food easier and makes it easier for the body to process sugars.
  • Eat Protein – Eating protein at every meal and making sure it is the first food group you eat can help reduce the risk of dumping. Protein should make up half of each meal post gastric bypass.
  • Eat complex carbohydrates – Brown rice, whole grains, pulses and unsweetened cereal release sugars slower than simple carbohydrates. Swapping white rice for whole meal pasta will help keep blood sugar regulated and prevent dumping
  • Eat fiber – Fiber slows down the digestive process and with a smaller intestine, a slower digestion of food is needed to prevent dumping.
  • Drink water between meals– Aim to drink 8 glasses of water a day to keep the body hydrated
  • Lie down after meals – Lying down causes a slower processing of food, reducing the risk of dumping


  • Eat lots of sugar – Cakes, biscuits and sweets containing high amounts of sugar. Sugar passes quickly through the digestive tract and triggers dumping syndrome.
  • Drink heavy, rich liquids – Nutritionally enhanced drinks, milkshakes and cream based drinks are best avoided as rich emulsified liquids are hard to digest.
  • Eat spicy foods – Spicy foods often trigger dumping syndrome
  • Drink with meals – Avoid liquid with food to slow the digestive system
  • Eat slouched – Sitting upright as you eat helps with digestion of solid food

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