Proper Portions After Weight Loss Surgery


Bariatric surgical procedures cause weight loss, in part, by restricting the amount of food the stomach can hold at at time. However, the capacity of the stomach pouch will depend on the type of procedure being performed (i.e. Lap-Band, laproscopic sleeve gastrectomy, Roux-en-Y gastric bypass, etc.), how far out the individual is from having surgery, and what type of food the person is eating. While the pouch will be extremely swollen and limited in space immediately following surgery, once healed it will allow a larger, yet still limited, amount of food.

But what if I can eat more than I could in the beginning, have I stretched out my stomach?

While the maximum capacity of the pouch may vary between individuals, it is often recommended that meals and snacks are limited to roughly 3-6 ounces per meal. This portion size will allow for adequate intake of protein while still offering calorie restriction.  If you notice that you can comfortably eat more than 3-6 ounces of food, it may be due to the type of food being consumed. Liquid and soft textures will be much more tolerable and comfortable than hard, dense textures. For example, someone who is post-op might be able to eat 6 ounces of Greek yogurt but only 3-4 ounces of meat or, be able to drink an 11 ounce protein shake but only tolerate ½ of a protein bar at a time. No matter what your pouch can hold, it’s important to make portion control a lifelong habit. This is especially true of easy to digest, simple carbohydrates such as candy, chips, crackers, etc.


  • Eat meals of off small, portion controlled, plates and bowls.

  • Measure foods with measuring cups rather than eating out of a large bag or package.

  • Use measuring spoons as serving utensils when dishing up your meal.

General targets for meal or snack portion sizes after bariatric surgery:

While it’s likely best to speak to a dietitian or your medical providers about your specific needs as an individual, these are some general guidelines for post-op patients:

Meal/Snack: 3-6 ounces (volume)

  • At least half of the meal be protein: ex. Fish, poultry, beef, eggs, dairy, soy products, etc.

  • 1/4 to 1/2 of the meal be produce: salad greens, vegetables, high fiber fruit

  • (Optional) A few bites of the meal are high-fiber starch: Ancient grains, legumes, root vegetables, etc.


What should my calorie, carbohydrate, protein, and fat breakdown be after weight loss surgery?

There is no “cookie cutter” way to answer this question. Often times calorie and macronutrient needs are based on medical diagnosis, age, gender, activity level, etc. It is best to discuss this with your surgical or medical team for individual assessment and tailoring. However, with that being said, here are some targets that post-op patients tend to follow:

  • Calories: 800-1200 per day (during weight loss phase)

  • Protein: at least 60-80 grams per day based on the A.S.M.B.S. guidelines

  • Carbohydrates: Equal or less than the number of grams of protein eaten (ex. If eating 80 grams protein, keep your carbohydrates less than 80 grams per day. It is important to talk with your medical team before reducing carbohydrates if you are using medications that help to control blood sugar levels.)

  • Fat: at least 20 grams per day, with an emphasis on unsaturated fats


Should I eat snacks?

If you can tolerate more than 6 ounces of food at a meal, you may be able to reach your protein targets with just 3 meals per day. However, some individuals find that when they eat smaller, more frequent meals, they notice that hunger, appetite, and blood sugar are more balanced and controlled. If you choose to eat snacks between your meals, aim for protein and fiber-rich options to keep you full and satisfied longer.

In a nutshell:

1.     Always practice portion control.

Use small plates, bowls, containers, and utensils to help monitor portion sizes for all types of food.

2.     Eat protein first at meals.

Protein, especially solid options, are important to eat at each meal and snack to ensure that protein targets are being met. However, eating protein first at meals also has the additional benefit of limiting how much can be eaten subsequently at meals. Due to the nature of protein taking longer to digest, by eating it first, it will also delay how quickly other foods will be broken down which will help keep you full longer and support better blood sugar control.

3.     Yes, you can eat carbs, but…     

Aim for healthy, high-fiber options as often as you can. Completely depriving yourself of your favorite foods can backfire, however over-indulging in them or eating them too frequently can also decrease your short and long-term weight, and wellness goals.