You will eat only liquid or puréed food for 2 or 3 weeks after the surgery. You will slowly add in soft foods, then regular food.

• When you start eating solid foods again, you will feel full very quickly at first. Just a few bites of solid food will fill you up. This is because your new stomach pouch holds only a tablespoonful of food at first, about the size of a walnut.
• Your pouch will get slightly larger over time. You DO NOT want to stretch it out, so DO NOT eat more than your provider recommends. When your pouch is larger, it will not hold more than about 1 cup (250 milliliter) of chewed food. A normal stomach can hold up to 4 cups (1 liter, L) of chewed food.

You will lose weight quickly over the first 3 to 6 months. During this time, you may:

• Have body aches
• Feel tired and cold
• Have dry skin
• Have mood changes
• Have hair loss or thinning hair

These symptoms are normal. They should go away as you take in more protein and calories as your body gets used to your weight loss.

Remember to eat slowly and chew each bite very slowly and completely. DO NOT swallow food until it is smooth. The opening between your new stomach pouch and your intestines is very small. Food that is not chewed well can block this opening.

• Take at least 20 to 30 minutes to eat a meal. If you vomit or have pain under your breastbone during or after eating, you may be eating too fast.
• Eat 6 small meals throughout the day instead of 3 big meals. DO NOT snack between meals.
• STOP EATING AS SOON AS YOU ARE FULL.

Some foods you eat may cause some pain or discomfort if you do not chew them completely. Some of these are pasta, rice, bread, raw vegetables, and meats. Adding a low-fat sauce, broth, or gravy can make them easier to digest. Other foods that may cause discomfort are dry foods, such as popcorn and nuts, or fibrous foods, such as celery and corn.

You will need to drink up to 8 cups (2 L) of water or other calorie-free liquids every day. Follow these guidelines for drinking:

• DO NOT drink anything for 30 minutes after you eat food. Also, DO NOT drink anything while you are eating. The liquid will fill you up. This may keep you from eating enough healthy food. It can also lubricate food and make it easy for you to eat more than you should.
• Take small sips when you are drinking. DO NOT gulp.
• Ask your provider before using a straw, since it may bring air in your stomach.

You will need to make sure you are getting enough protein, vitamins, and minerals while you are losing weight quickly. Eating mostly protein, fruits, vegetables, and whole grains will help your body get the nutrients it needs.

Protein may be the most important of these foods early after surgery. Your body needs protein to build muscles and other body tissues, and to heal well after surgery. Low-fat protein choices include:

• Skinless chicken
• Lean beef or pork
• Fish
• Whole eggs or egg whites
• Beans
• Dairy products, which includes low-fat or nonfat hard cheeses, cottage cheese, milk, and yogurt.

After gastric bypass surgery, your body will not absorb some important vitamins and minerals. You will need to take these vitamins and minerals for the rest of your life:

• Multivitamin with iron
• Vitamin B12
• Calcium (1200 mg per day) and vitamin D. Your body can absorb only about 500 mg of calcium at a time. Divide your calcium into 2 or 3 doses during the day. Calcium must be taken in the “citrate” form.

You may need to take other supplements also.

You will need to have regular checkups with your provider to keep track of your weight and to make sure you are eating well. These visits are a good time to talk with your provider about any problems you are having with your diet, or about other issues related to your surgery and recovery.

Avoid foods that are high in calories. It is important to get all of the nutrition you need without eating too many calories.

• DO NOT eat foods that have a lot of fats, sugar, or carbohydrates.
• DO NOT drink much alcohol. Alcohol has a lot of calories, but it does not provide nutrition.
• DO NOT drink fluids that have a lot of calories. Avoid drinks that have sugar, fructose, or corn syrup in them.
• Avoid carbonated drinks (drinks with bubbles), or let them go flat before drinking.

Portions and serving sizes still count. Your dietitian or nutritionist can give you suggested serving sizes of the foods in your diet.

If you gain weight after gastric bypass surgery, ask yourself:

• Am I eating too many high-calorie foods or drinks?
• Am I getting enough protein?
• Am I eating too often?
• Am I exercising enough?

Call your provider if:

• You are gaining weight or you stop losing weight.
• You are vomiting after eating.
• You have diarrhea most days.
• You feel tired all the time.
• You have dizziness or are sweating.