I like to stop by my favorite coffee shop on the morning commute and order a latte or cold brew to go.

Yet what often surprises me when I’m standing in line is how many people order “oat milk” in their coffee — mostly because I don’t really know what oat milk is.

From what I’ve heard, the oat milk trend took off at the start of the pandemic in spring 2020. Grocery stores reportedly couldn’t keep the plant-based drink on their shelves when all of us devoted coffee drinkers were forced to make our own brew at home. 

Granted, oat milk sales are still just a fraction of sales compared to real dairy milk. 

However, more coffee shops are adding oat-milk lattes to their menus — even though (or perhaps because) oat milk often costs twice as much as real milk.

Oat drinks are the latest “it” beverage in the plant-based beverage fad, much like almond, coconut, soy and rice drinks before it, explains Stephanie Clark, a dairy food scientist and nutritionist at Iowa State University. 

There’s a current perception — fueled by celebrities and so-called “wellness” influencers — that plant-based foods are the healthier choice.

Yet from a nutritional perspective, oat drinks and other plant-based alternatives can’t compete with the unique blend of 13 essential vitamins and micronutrients that you get from real milk and dairy, Clark says.

“I want to make clear that I’m not against plant-based products,” Clark says. “What I don’t like is when the (food marketers) masquerade as if they are equivalent to dairy, because they’re not.”

Legally, the U.S. Food and Drug Administration defines milk as a dairy beverage that comes from a healthy, lactating cow.

Oat beverages and other plant-based drinks are manufactured in factories. Oats are ground up, mixed with water and filtered to remove the grittiness and mimic the mouth feel of real milk, Clark says. 

“A bunch of sugar is also added to most (plant-based drinks) because oats aren’t palatable on their own. They don’t taste good. We always add something to (oats) to make them taste better,” Clark says.

Oat milk and plant-based drinks are also fortified with calcium and other vitamins and minerals so they more closely mimic real milk nutritionally. 

However, Clark says these added vitamins often end up unused at the bottom of the beverage carton. 

Plus, these nutrients aren’t as bioavailable — or easily absorbed by our bodies — compared to the naturally existing nutrients in real milk and dairy.

Real milk offers 13 essential nutrients, including calcium, magnesium, vitamin B12, phosphorus and high-quality protein, Clark says.

Protein, in particular, helps prevent muscle loss as we age and aids in weight management, by helping us feel fuller longer.

Real milk offers about 8 grams of protein per 1 cup serving. In comparison, oat drinks contains 3 grams of protein per 1 cup serving. 

Oat drinks are also higher in carbohydrates and added sugars, Clark says.

Embarrassingly, I also admitted to Clark that I've considered cutting back on dairy over worries about gaining weight. 

Yes, real dairy has slightly more saturated fat and cholesterol than plant-based beverages. However, Clark says it’s a myth that all fats are bad for our health.

In particular, research has repeatedly shown that dairy fats don’t cause weight gain or hurt cardiovascular health — and may actually be protective of heart health, Clark says.

“It’s good to have some plant-based (fats) in our diet because they have some unsaturated fats that have been associated with positive health outcomes,” Clark says. “But we have plenty of evidence that dairy products are associated with positive health outcomes as well. … We need a variety of fats and nutrients in our diet.”

As for weight gain, Clark said it isn't real dairy that is adding extra calories to our diets. It’s the pastry we order with the coffee, or the chocolate syrup in the latte, or too-big portion sizes.

“It’s about making good food choices throughout the day...,” Clark says. “Do not stress about the milk that you choose as the base of your beverage.”

Clark says if you have a dairy allergy, then plant-based alternatives are a good choice. 

And if you’re allergic to cow's milk, then maybe try goat or sheep dairy foods.

For people who are lactose intolerant, you could try fermented dairy products, like kefir, which are nutritious choices without the lactose.

“I strongly believe that dairy should be part of our diet, and everything (in our diets) in moderation,” Clark says.