Gastric bypass surgery is carried out to change the digestive system anatomy. This is meant to help in weight loss. In this surgery stomach size is reduced and a part of small intestine is bypassed. So naturally the quality and quantity of diet changes after such surgery. It is also necessary to select a proper diet for proper nutrition and better weight loss.
The patient cannot take any food immediately after the surgery for one or two days. Then slowly, a particular food, which helps in gastric bypass diet progression, is allowed for the patient. These foods are chosen so as to aid in healing after the surgery, especially foods which would not put too much strain on operated parts.
Liquids: initially for first two days fluids like juice, milk, broth, cooked cereals containing more water and strained soups are given.
Pureed or semisolid foods: Thick paste like or semisolid foods with no pieces in it are given for generally three to four weeks.
Soft food: Soft fruits, cooked vegetables, ground and cooked meat, such soft foods are generally given for the next eight weeks
After that, gradually patient’s diet can be changed to foods of normal consistency.
These meals, during the gastric bypass diet progression are given in small quantities, but more times during a day. Liquids should be sipped slowly all through the day. In the beginning generally more numbers of small meals are given which are later tapered to three regular diet meals a day.
The meals given are generally rich in protein content (like eggs, low fat dairy products, lean meats etc) because proteins are necessary for body repairs, especially after surgery. The time required for the progression of diet from one step to another, varies from patient to patient. On an average, patient starts taking regular textured diet three months after the surgery.
Because of the permanent changes made to the anatomy of the digestive system, changes in the diet and eating habits are also necessary:
Small meals: Stomach capacity is reduced by the surgery and it can accommodate only one-ounce food initially. Slowly it expands, but even then, after three months, it may hold 1 to 1 ½ cup of food at one mealtime. So meal portions should be small. With more food, there are chances of nausea, vomiting and stomach pain. Also, the calories would increase.
Eating and drinking slowly: This is essential in order t avoid dumping syndrome. If quickly eaten food went quickly into the small intestine, in bigger quantity, it may result in dizziness, sweating, nausea, vomiting and diarrhea. Gastric bypass diet should be low in fat and sugar. Liquids should not be taken along with the meals. There should be a gap of half an hour before or after the meal. Eating and drinking should be very slow.
Proper chewing of food: While gulping he food, no pieces should remain unchewed. After surgery the opening from stomach into the small intestine is quite narrow. So if bigger pieces of food remain in the swallowed food, those would get stuck in the opening and the rest of the food wouldn’t pass from stomach into intestine. This blockage could lead to stomach pain, nausea, vomiting. Therefore food should be eaten in small bites and chewed to smooth paste before gulping.
No drinking liquids along with the meals: As the stomach size is surgically reduced, large quantities of food + liquids would cause vomiting nausea, pain. Drinking liquids with meals will give feeling of fullness and thus fewer nutrients would be available to the body. Keeping gap with the meals, at least 6 – 8 glasses of liquids should be taken to avoid dehydration.
Choosing food carefully: if any food is giving uneasy feeling, it should be avoided. Because of surgery and the narrow opening of stomach into small intestine, there could be blockage and nausea, pain, vomiting etc with any particular food. So only one new food should be tried at a time. Generally, after a gastric bypass, foods like raw vegetables, rice, pasta, bread, milk, meat etc and carbonated drinks can cause some trouble.
Necessary vitamins and nutrients: As a part of stomach and small intestine are removed by this surgery, so body cannot absorb some nutrients necessary for the function. So the prescribed vitamins and mineral supplements should be taken to avoid any deficiencies.
This surgery is carried out to help weight loss. After surgery, if the gastric bypass diet is followed properly, the patient can loose 50 to 60% of initial weight in first two years. With the same diet and physical activities, the weight could be maintained for a longer period. But if the proper diet is not followed and if fat and sugar containing foods are consumed without any exercise, then there could be weight gain even after the gastric bypass surgery.