Should I Be Drinking Milk Alternatives?​

Bariatric surgery can reveal, worsen, or mimic lactose intolerance in some patients, but many people continue to tolerate dairy products after surgery. That’s an important distinction because a lot of people unnecessarily eliminate dairy and lose a valuable source of protein, calcium, and vitamin D. There are a lot of milk alternatives out there, but patients shouldn’t conclude that they’re always inherently healthier.

Most grocery stores these days have an ever-growing selection of milk alternatives. Soy, almond, oat, hemp, cashew, macadamia nut – shelf-stable, refrigerated, sweetened, unsweetened – you name it. You might wonder if they’re healthier than traditional dairy milk, whether they’re only intended for people with lactose intolerance, and whether bariatric patients should be relying on them before or after surgery.

Some patients start to notice that they may not tolerate milk or milk products as well as they did before surgery. While surgery doesn’t necessarily cause clinically diagnosed lactose intolerance, changes in the digestive tract can make it harder to digest dairy or make an intolerance more apparent. Tolerances of all sorts can happen after surgery, with abounding individual variances, and milk alternatives can be a good choice for some patients. But they are not automatically healthier than dairy milk.

What is Lactose Intolerance?​

Lactose is a naturally occurring sugar found in milk and dairy products, and lactose intolerance is simply the inability to fully digest it. That inability is due to the body not producing enough lactase, the enzyme responsible for breaking lactose down into smaller sugars that can be absorbed and used for energy.

Lactose intolerance is not the same thing as a dairy allergy. With an allergy, the immune system reacts to proteins in milk, but lactose intolerance is a digestive issue. Common symptoms of lactose intolerance include bloating, gas, abdominal cramping, diarrhea, and general gastrointestinal discomfort after consuming dairy products.

The relationship between lactose intolerance and bariatric surgery can be a little complicated. Food intolerances are a relatively common consequence of bariatric surgery, but the reasons behind them are multifactorial.

Sometimes, bypassing portions of the small intestine, as in gastric bypass surgery, makes pre-existing lactose digestion issues more noticeable, and symptoms become more apparent afterward. Other reasons for dairy-related discomfort after bariatric surgery can be related to altered gastric emptying, changes in gut hormones, food texture, fat content, or the high sugar content found in some dairy products. For instance, symptoms of dumping syndrome can closely resemble symptoms commonly associated with lactose intolerance, including cramping, bloating, nausea, and diarrhea.

The increase in clinically confirmed lactose intolerance is much smaller than many people assume. Patients who believe they have become lactose intolerant after surgery may actually be reacting to other aspects of a food rather than lactose itself.1

That’s a caveat to pay attention to. After bariatric surgery, malabsorption of essential vitamins and minerals is prevalent, and unnecessarily eliminating all dairy products can make it more difficult to obtain sufficient protein, calcium, vitamin D, and other nutrients. Before writing off dairy, it’s worth considering whether the issue is lactose itself, a specific food, portion size, fat content, added sugars, or another post-surgical dietary factor.

Are Milk Alternatives for Everyone?

​Not necessarily. But they also aren’t a bad idea. For people with actual intolerances and allergies, it’s great that so many options exist. But it’s a misconception that dairy milk or alternatives are inherently healthier than the other. They’re just nutritionally different. Looking at the nutrition label is more important than focusing on whether the product comes from a plant or an animal for those without lactose intolerance, allergies, or other food preferences.

Unsweetened almond milk can be relatively low in protein, but it’s also usually low in calories and carbohydrates. On the other hand, soy milk can contain levels of protein and amino acids similar to traditional dairy, but soy itself is also a known allergen. Oat milk could provide additional fiber, but some varieties contain added sugars that can undermine healthy eating. Fortification also varies widely between brands and products. Patients should pay attention to protein content, calcium, vitamin D, added sugars, calories, and overall nutrient density. A product that is well tolerated but provides little nutritional value won’t help with meeting post-operative goals.

It’s not always fat that melts away when losing a significant amount of weight; muscle can also wane. Increasing protein intake helps preserve lean muscle mass and promote long-term weight management. Bariatric surgery also increases the risk of deficiency in specific nutrients, like calcium, B vitamins, and vitamin D, so the best food choices are the well-tolerated ones that provide adequate nutrients. For some patients, that might come from traditional dairy milk. For others, it may be lactose-free milk, fortified soy milk, or another alternative that better fits their needs and preferences.

Keep It Simple

​It’s easy to get caught up in trends, but patients benefit the most from focusing on a few basic nutrition principles instead.

• First, prioritize protein. Whether it comes from dairy products, lactose-free products, soy milk, protein shakes, or other foods, you need adequate protein.
• Second, pay attention to vitamins and minerals. Don’t center your choices solely on the source of a food – consider whether it is helping you meet your nutritional needs.
• Third, keep track of what you can and can’t tolerate. Everyone’s experience is different, and food tolerances can evolve. If dairy products cause discomfort, alternatives may be appropriate. If dairy products are well tolerated, there’s really no reason to avoid them. It’s also appropriate to keep your diet interesting by incorporating different types of milk alternatives alongside regular dairy products

Greek yogurt, Icelandic yogurt, kefir, cottage cheese, low-fat yogurt, and lactose-free milk are generally better tolerated and provide the sustenance you need. Some patients find that full-fat milk, ice cream, cream-based products, sweetened dairy products, and some aged cheeses may be more difficult to tolerate.

The best source of guidance is your bariatric care team or dietician to find out whether what’s on the menu is helping or hindering your progress. At Bariatric Specialists of the Carolinas, we help patients navigate dietary changes before and after surgery so they can meet their nutritional needs, support recovery, and build sustainable habits for long-term success.

1. Brzostek, K., & Boniecka, I. (2025). Food Intolerance After Bariatric Surgery: A Narrative Review of Prevalence, Mechanisms, and Dietary Management. Nutrients, 17(19), 3118. https://doi.org/10.3390/nu17193118.