Lactose intolerance is a common digestive problem that is caused by the body’s inability to fully digest the lactose (sugar) that is found in milk. Eating or drinking lactose-rich dairy products can cause very unfavorable side effects like bloating, stomach pain, gas, and diarrhea.

So if you were lactose intolerant before bariatric surgery, you may be wondering if it can occur after bariatric surgery?

In short, yes! While it is not a particularly common side effect, it is possible that those who undergo bariatric surgery may become lactose intolerant. For this reason, removing or limiting milk as well as some other dairy products from your diet may be necessary.

Facts About Milk and LactoseCan Lactose Intolerance Occur After Bariatric Surgery?

While there are some health benefits that can come from drinking milk such as better bone health, lowered blood pressure, lowered risk of heart disease, and prevention of diabetes, it is not recommended for everyone.

Milk contains a naturally present sugar called lactose which some may have an intolerance to. In some cases, bariatric procedures such as gastric sleeve and gastric bypass can cause lactose intolerance in patients due to the changes in how the lactose is passed through the digestive system.

How much lactose is in one 8 ounce glass of milk?

  • Non-fat milk = 12 grams of lactose
  • 1% milk = 13 grams of lactose
  • 2% milk = 12 grams of lactose
  • Whole milk = 12 grams of lactose

For those who do not have an intolerance to lactose before surgery, we may recommend that you remove milk and other dairies from your diet. After surgery, you can begin to introduce milk at about stage 3 in small increments to see whether or not you have developed an intolerance.

Recommended Milk Substitutes Bariatric Surgery

When introducing foods and drinks back into your diet after bariatric surgery it can be helpful to maximize the benefits. Below, are some alternatives to milk that patients can include in their diet:


A great milk product that we recommend is fairlife® because it is lactose-free and has a higher level of protein. This is a real milk product, but it has been ultrafiltered to provide 50% more protein, 30% more calcium, and half the sugars of regular milk. One 8 ounce glass of 2% fairlife® milk contains only 6 grams of sugar and 13 grams of protein as opposed to the 12g of sugar and 8 grams of protein found in regular 2% milk.

Other Milk Substitutes

  • Unsweetened Almond Milk
  • Coconut Milk
  • Cashew Milk

These 3 milk substitutes are great lactose-free dairy products that patients with lactose intolerance can have. These products are very high in protein but are lactose-free and low in carbs and sugar.  They are great for mixing in your protein shakes in place of water.

Milk Substitutes to AVOID!

lactose intolerance, milk substitutes to avoid.Avoid soymilk or any sweetened flavored milk or milk substitute. These products may be lactose-free but are generally high in added sugar, which is not conducive to a pre-op or post-op diet.

Consult Your Nutritionist and Get Regular Checkups

At Mexico Bariatric Center, we like to share this information to further spread knowledge to best serve our former and future patients. We recommend that any who are planning to or have undergone bariatric surgery consult a nutritionist and get regular checkups to help better ensure a healthy recovery.

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