Gastric Bypass Diet: Nutritional Needs after Weight-loss Surgery

What you eat, how you eat and how much you eat changes after gastric bypass surgery.

With your stomach pouch reduced to the size of a thumb, you'll need to strictly follow a gastric bypass diet. This diet - which your doctor or dietitian creates for you based on your particular profile and nutritional needs - tells you what type and how much food to eat with each meal and the required consistency and texture of the food.

You won't be allowed to eat for one to two days after the surgery. Then you consume specific foods according to a diet progression. The purpose of the diet progression is to allow your stomach (now known as “pouch”) time to adapt to processing food and to allow you to lose weight while maintaining good nutrition.

The following are common phases in the gastric bypass diet progression:

• Liquids. Foods and fluids that are liquid or semi liquid at room temperature and contain mostly water, such as broth, juice, milk and cooked cereal. In most cases, you stay on a liquid diet for two to three days.
• Pureed foods. Foods with a consistency of a smooth paste or a thick liquid. Pureed foods contain no distinct pieces. You usually eat pureed foods for three to four weeks so that your stomach has time to fully heal.
• Soft foods. Foods that are tender and easy to chew, such as ground or finely diced meats, canned or soft, fresh fruit, and cooked vegetables. You usually eat soft foods for eight weeks before progressing to regular-textured foods, as recommended by your dietitian or doctor.

During the diet progression, you eat many small meals a day and sip water frequently. You might first start with six small meals a day, then progress to four meals and finally, when eating regular foods, decrease to three meals a day. Typically, each meal includes protein-rich foods, such as lean meat, yogurt and eggs. Protein is important for maintaining and repairing your body after surgery.

How quickly you move from one step to the next depends on how fast your body adjusts to the change in eating patterns and the texture and consistency of food. In most cases, people start eating regular foods three months after surgery.