Gastric bypass is an operation performed to treat obesity. With this procedure a small stomach pouch is created by stapling part of the stomach together or vertical banding. The purpose of this is to limit the amount of food that you can physically eat.
There are two types of bypass surgery :
Generally, two weeks prior to gastric bypass surgery a liquid diet is essential. The diet should be made up of around 4 protein shakes per day, and an unlimited amount of clear liquids.
Any type of shake is permitted, as long as it contains at least 20grams of protein. Calorific value is also of importance, each shake should be no more than 150 calories, but the lower the calorie content the better.
The purpose of the protein shakes is mainly to get the body into an optimum nutritional state for surgery. The clear liquids on the other hand are not only important to keep the body appropriately hydrated, but shrink the liver which sits on top of the stomach. As the liver is held up during the operation, shrinking makes the whole process more straight forward. Patients will also be required to take a multi vitamin. Women are required to take extra calcium supplements in addition.
After gastric bypass surgery, the new smaller stomachs volume of what it can hold is dramatically reduced. Reducing from about 1 quart to approximately 2 tablespoons or 1 ounce over time, the stomach pouch will stretch until it can hold up to 6-8 ounces at any one time.
The 'post gastric bypass diet' unfolds in several different stages, each appropriately adapted to the necessary amount of time since surgery.
For the first 8-10weeks, the foods consumed must be very smooth in texture. In the first instance following the operation, only clear liquids must be consumed. It starts with just small sips of water, but then progresses to drinks such as sugar-free juice and clear broth. Diet soda (flat not fizzy) should be limited to around 2-3 ounces at a time. This stage of the diet usually lasts at least a few days, possibly 1-2days for some patients after the operation.
Next, assuming there are no complications during the clear liquid stage of the diet, patients are advanced to high protein shakes. This stage of the diet is started before a patient is discharged from the hospital, and lasts for approximately 1-2weeks.
The next stage consists of soft pureed foods. The physician will indicate when it is time to start these foods. Most patients are able to start about two weeks after leaving hospital. Some patients will need to wait a little longer.
Again high protein foods such as scrambled eggs, low-fat cottage cheese and blended lean cuts of meat or fish are consumed. It is very important that meats are blended well and are extremely soft and smooth in texture.
The last gradual stage of the diet usually comes no less than 8weeks after the operation. This will be a regular diet that should be looked at as a lifestyle change. It includes all five main food groups. Dieticians advise patients to start every meal with high protein foods, such as lean meats or milk.
Any snack or meal consumed should be small in size. Liquids should also be consumed between meals. It is recommended to eat 3-6 small meals per day, and never over eat.