Gone are the days when the most complicated choice you had to make in the milk section of the dairy aisle was reduced fat or whole. Now, you’ll find carton after carton of dairy-like beverages made from foods you never thought could be “milked” — almonds, oats, rice, peas.

While cow’s milk is still the most popular according to retail sales, nondairy alternatives hit an estimated $2.95 billion last year, up 54 percent from five years earlier, according to the market research firm Mintel.

These plant-based alternatives are typically made by soaking the legume, nut, grain or other main ingredient and then pressing and straining the liquid, or “milk.” Many people prefer them because they want or need to avoid dairy, but some choose them because they believe they are healthier than cow’s milk. Some experts urge consumers to look beyond the hype and to examine the nutrition label, however, because some may not be as healthful as they seem.

Are plant-based milks good for me?

This will depend on which type of plant milk you drink, whether it’s fortified, how many added sugars it contains and how it fits in to your overall diet. You shouldn’t assume, for instance, that plant milks contain the same nutrients as cow’s milk, even if the drink is white and has the same creamy texture. And some of the sweetened versions can contain more added sugar than a doughnut.

“In general, these nondairy milks have been promoted as healthier and that’s not necessarily the case,” said Melissa Majumdar, a spokeswoman for the Academy of Nutrition and Dietetics.

Cow’s milk is naturally rich in protein, calcium, potassium and B vitamins, and is often fortified with vitamin A (which is naturally present in whole milk) and vitamin D. While many plant-based milks are enriched with many of the nutrients found in cow’s milk, not all are.

And many don’t provide enough of certain key nutrients like protein, potassium and vitamin D, Jackie Haven, deputy administrator for the U.S. Department of Agriculture’s Center for Nutrition Policy and Promotion, wrote in an email: “Usually, these beverages do not include all of the necessary nutrients needed to replace dairy foods.”

That being said, nondairy beverages can be important alternatives for those who are allergic or intolerant to milk or who are otherwise avoiding dairy. And they can be a part of a healthy diet as long as you pay attention to the nutrition facts label and make sure you’re getting the same essential nutrients you’d normally get from real milk.

“You can still meet your nutrition goals without drinking cow’s milk,” said Megan Lott, a nutritionist and deputy director for the Healthy Eating Research program at Duke University. “It just takes really educating yourself.”

How do the different types of plant milks compare?

According to SPINS, a market research company, the six most popular plant-based milks based on sales data from the past year are almond, oat, soy, coconut, pea and rice (excluding blended versions, like coconut almond).

Here’s how the original or unsweetened versions of each stack up to one another and to whole milk in terms of taste, protein, calories, fats and other attributes. (We used whole milk for comparison because it has become more popular in recent years, but keep in mind that the U.S.D.A. dietary guidelines recommend drinking low fat and skim versions rather than whole. All versions below contain calcium and vitamin D.)

Almond milk: This nutty-flavored beverage is the most popular plant milk, according to SPINS. One cup of the unsweetened version has just 37 calories — about a quarter the amount in whole milk — and about 96 percent less saturated fat. But it is no match for cow’s milk (or raw almonds themselves) in terms of protein — it has just about 1 gram, compared with the 8 grams present in whole milk. If you have a nut allergy, experts recommend avoiding it as it may trigger an allergic reaction.

Oat milk: Sales of this thick, creamy drink increased by 182 percent since last year, according to SPINS, making it one of the fastest growing plant milks. One cup of the popular Oatly! brand’s original version has little saturated fat (0.5 grams) and slightly fewer calories than whole milk (120 versus 146), but has 7 grams of added sugars (plain milk has none) and only 3 grams of protein.

One cup does have some fiber — 2 grams — but Dr. Edwin McDonald IV, an associate director of adult clinical nutrition at the University of Chicago Medicine, said that’s not very much. “If you are looking for health benefits from oat milk, you’re better off eating oatmeal,” he said. One cup of oatmeal, for instance, has twice as much fiber as one cup of oat milk. Fiber is important for gut health, cholesterol and blood sugar control, and for maintaining your weight.

Soy milk: When fortified with calcium and vitamins A and D, soy milk is the only nondairy milk that is comparable to cow’s milk in terms of nutrient balance, according to the dietary guidelines. One cup has 6 grams of protein, 105 calories and about 89 percent less saturated fat than whole milk. Made from soybeans, it has a similar consistency to cow’s milk and is a natural source of potassium. “If you are looking for more of a nutritionally balanced milk substitute, then pea and soy are going to be the best,” said Dr. David Ludwig, an endocrinologist and obesity researcher at Boston Children’s Hospital.

While there’s been some concern about the estrogen-mimicking compounds called isoflavones in soy, there isn’t enough data to prove any harm or benefit. If you’re allergic to soybeans, though, experts say to avoid it.

Coconut milk: Made from the grated meat of coconuts, it’s naturally sweet and has about half as many calories as whole milk, but has little protein (0.5 grams per cup), and has 5 grams of saturated fats — about the same amount as whole milk — with no healthy unsaturated fat. As with dairy fat, there’s the concern that coconut fat can raise the levels of LDL, or “bad,” cholesterol, said Alice H. Lichtenstein, a Gershoff professor of nutrition science and policy at Tufts University.

Pea milk: Sometimes called “plant protein milk,” this beverage is made from yellow split peas. As with other plant milks that are made from legumes, like soy milk, pea milk is high in protein (8 grams per cup) and unsweetened versions contain about half the calories of whole milk, and just half a gram of saturated fat. “My favorite nondairy milk is pea milk,” said Dr. McDonald, who is lactose intolerant and a trained chef. That’s because of its protein, and a texture he likens to cow’s milk — somewhat creamy with a mild taste.

Rice milk: Made from brown rice, the milk has a naturally sweet taste. It has slightly fewer calories than whole milk (115 versus 146 per cup), and no saturated fat; however it’s very low in protein (0.7 grams per cup). When compared with other plant-based milks, “there doesn’t seem to be any benefit from rice milk,” Dr. Lichtenstein said.

The beverage also has fast-digesting carbohydrates, Dr. Ludwig said, which can quickly convert into glucose, spiking insulin and blood sugar levels — a potential concern for people with diabetes or with severe insulin resistance.

Should I be concerned about added sugars?

Yes. To make plant milks more palatable, manufacturers will often add sugars in the form of cane sugar, rice syrup and more. While one cup of plain cow’s milk contains 12 grams of sugars, all of it comes from naturally occurring lactose, which is digested more slowly and keeps your metabolism more stable over time than refined sugars.

However, for some, a cup of coffee with unsweetened milk isn’t satisfying. “People like the sweetened versions of those,” said Suzanne Devkota, an assistant professor at the Cedars-Sinai Medical Center who specializes in nutrition and metabolism. “But now the carbohydrate level of the plant alternative is twice as much as the cow’s milk.”

Unsweetened almond milk, for instance, has just 2 grams of naturally occurring sugar per cup. The same amount of WestSoy Chocolate Peppermint Stick Soymilk has 25 grams of sugar — 2.5 times the amount in one original glazed doughnut from Krispy Kreme. Make sure to keep an eye on the nutrition label, and watch out for flavored versions, like those labeled “vanilla” or “chocolate,” because they often contain added sugar.

“What you don’t want is to have a nondairy product really be your dessert,” said Penny Kris-Etherton, a professor of nutritional sciences at Penn State. “You want it to function as a dairy product in your diet.”

Are plant milks worth the money?

While the price of plant-based milks can range widely — from $3 or more for a half-gallon — regular milk is often much cheaper. A gallon of whole, on average, costs $3.58.

“Cow’s milk is going to be the least expensive,” said Ms. Majumdar, of the Academy of Nutrition and Dietetics. “But it has the most nutrients, so you are getting more bang for your buck.”

Christopher Gardner, a nutrition scientist and professor of medicine at Stanford Prevention Research Center, however, said that for him, the higher price of plant milks is worth it for animal welfare and environmental reasons. “I’ve never met a belching soybean or pea,” he said, referring to cows’ emissions of methane gas. “If you are an eco-warrior, it could be worth the cost.”

Not all plant milks are eco-friendly, though. It requires an estimated 15 gallons of water to grow just 16 almonds; and most are grown in drought-stricken California.

Are plant-based milks bad for me?

“We don’t have to be afraid of them,” Dr. Ludwig said. “But concern creeps in as you start to increase the amount.” Because of their lack of certain nutrients, low level of protein and high amount of carbohydrates in some, Dr. Ludwig recommended drinking no more than one cup per day. While there have been many studies on cow’s milk and how it affects bone health and heart disease risk, there’s very little research into plant milks because most haven’t been around for as long.

Young children also shouldn’t be exclusively swapping plant milks for cow’s milk unless there is a medical or special dietary reason for them to do so, since some plant milks may not provide the same essential nutrients they’d otherwise get from cow’s milk.

Dr. Gardner said that it’s important to focus on consuming whole foods, and not the processed versions. Eating whole soybeans, oat cereals and almonds is preferable to drinking their milks. “When you make milk of them, you are removing some of the nutrients,” he said.