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Your diet after gastric bypass surgery


Alternate Names

Gastric bypass surgery - your diet

What to Expect at Home

You had gastric bypass surgery. This surgery made your stomach smaller and changed the way your body handles the food you eat. You will eat less food, and your body will not absorb all the calories from the food you eat.

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, mood changes, and hair loss or hair thinning. These problems should go away as your body gets used to your weight loss. Because of this quick weight loss, you will need to make sure you are getting enough protein, vitamins, and minerals.

Your weight loss will slow down after 12 to 18 months. Sticking with your diet and exercise plan will help as it gets harder to lose weight.

Bypass surgery alone is not a solution to losing weight. It can train you to eat less, but you still have to do much of the work. You will need to follow the exercise and eating guidelines that your doctor and dietitian gave you.

Eating Healthy

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

  • 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 larger over time. You do not want to stretch it out, so do not eat more than your doctor or dietitian recommends. When your pouch is larger, it will not hold more than about 1 cup of chewed food. A normal stomach can hold up to 4 cups of chewed food.

Once you are eating solid food, 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 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.

Drink up to 8 glasses of water or other liquids that do not have calories every day. Follow these guidelines for drinking:

  • Do NOT drink anything for 60 minutes before or after you eat food, or while you are eating. This will fill you up. Filling up on liquids may keep you from eating enough healthy food.
  • Take small sips when you are drinking. Do not gulp. Do NOT use a straw, since it brings air in your stomach
  • Do NOT drink fluids that have a lot of calories. Avoid drinks that have sugar, fructose, or corn syrup in them. You should also avoid carbonated drinks (drinks with bubbles).
  • Follow your diet carefully. Your doctor, nurse, or dietitian will teach you about foods you should eat and foods you should avoid. It is very important to follow your diet.
  • Your doctor may prescribe several vitamins.
  • You will need regular checkups with your doctor to follow your weight and make sure you're eating well.

Avoid foods that are high in calories. It is important to get all of the nutrition you need without eating too many calories. See also: How to read food labels

  • Do NOT eat foods that contain a lot of fats, sugar, or carbohydrates.
  • Do NOT drink much alcohol. Alcohol contains a lot of calories, but it does not provide nutrition. Avoid it if you can.
  • Eat mostly protein, fruits, vegetables, and whole grains.

These foods may cause some pain or discomfort when you eat them:

  • Pasta, rice, bread
  • Raw vegetables
  • Any dry, sticky, or stringy food
  • Meats

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

  • Am I eating too many high-calorie foods or fluids?
  • Am I eating too often?
  • Am I exercising enough?
When to Call the Doctor

Call your doctor or nurse 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.
Related Taxonomy

Review Date: 2/12/2009
Reviewed By: Crystine Lee, MD, Department of Surgery, Marin General Hospital, Greenbrae, CA. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
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