Foods like avocados, kale, and quinoa are showing up on more plates as people jump on the health-food bandwagon. And now they’re showing up in pet food bowls, too.

“Anything that has gone on in human trends has shown up in pets,” said Tom McNeely, chief executive officer of Pet Retail Brands, which was formed by the July merger of Pet Valu and Pet Supermarket.

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The U.S. pet food business is worth more than $20 billion a year, according to industry experts. And as more people have taken care to eat better-for-you foods, pet owners have put more thought — and money — into feeding their pets.

The preoccupation with what pets eat has a lot to do with the “pet humanization” trend, Mintel wrote, with flavor and nutrition driving revenue. “The pet food humanization trend translates into pet owners wanting the same quality and safety standards on pet food as their own food,” wrote Amy Kraushaar, Mintel’s U.S. category manager for food and drink and food service.

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Premium brands include Merrick, which touts “leading levels of glucosamine and chondroitin” that humans take for osteoarthritis and joint health; Dogs Love Kale pet treats; Natural Balance, which offers vegetarian food; AvoDerm, which includes avocado; and Orijen, which features “fresh free-run poultry,” “whole nest-laid eggs,” and “whole wild-caught fish.”

Dog food considered “premium” made up nearly half (47%) of the dog food sold in a recent 12-month period, according to a 2015 American Pet Products Association study.

A 25-pound bag of Merrick Grain-Free Real Texas Beef and Sweet Potato dry dog food sells for $53.98 on Amazon.com Inc. AMZN, -1.63% A 28.6-pound bag of Orijen adult dog food was $83.99. And a 27.5-pound bag of Purina One SmartBlend dry dog food with turkey and venison (“Real turkey is the #1 ingredient,” the description said) was $30.99.

The amount people are willing to spend on pet food isn’t always tied directly to their income, according to McNeely. “You can’t tell what dog food people will buy based on the car they drive up in,” he said.

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Pet humanization goes beyond diet.

“The trend is really all about our pets being a true member of our families and participating in the activities we love — like a baseball game or camping — wearing similar apparel such as the athleisure trend, as well as eating foods similar to what we eat,” said Evelia Davis, vice president of dog and cat consumables at PetSmart.

Only Natural Pet, available exclusively at PetSmart, was inspired by a Paleo diet for cats and dogs using what Davis calls a “prey model” of 50% protein, 40% fat and 10% carbohydrates.

“We attended Interzoo, a global pet show in Germany, recently and there were hundreds of international pet food manufacturers and I was surprised at how many listed ‘human food grade’ for their ingredients and manufacturing process,” said Allen Simon, CEO of PetProducts.com. “One French manufacturer present at the show even invited people to taste their dog food.”

With more brands competing for a share of the premium pet food space, retailers are taking measures to appeal to doting pet parents.

“We have to compete on convenience, selection and newness,” said McNeely. He says his business is akin to the fashion industry, in that stores will try a number of new brands each year. Some will work and some won’t.

U.S. pet food sales totaled $23.05 billion in 2015, according to the American Pet Products Association, part of the $60.28 billion that Americans spent on their pets last year. Cats and dogs are most popular (in 42.9 million and 54.4 million U.S. households, respectively), but fish, reptiles, and even horses are in more than 30 million households as well.

Nestlé SA NESN, -0.53% , whose brands include Purina and Friskies, is the pet food leader, according to Mintel. Supermarkets account for a quarter of all pet food sales with pet specialty retailers, drugstores, and warehouse clubs like Costco Wholesale Corp. COST, -0.32% account for the other 75%.

When asked what impacts their decision about pet food, 45% told Mintel it’s whether their pets like he taste, 42% said price, and 36% said it’s whether the food is made in the U.S. The remaining responses largely revolved around the recipe, such as whether it’s natural (32%), if real meat is the first ingredient (27%), whether it’s organic (13%), gluten-free (7%) or if the ingredients are locally sourced (5%).

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More than half (54%) of pet owners reported to Mintel that they are satisfied with their pet food brand, while 28% said they sometimes experiment. “People who are healthier and following trends are much more likely to try new things,” said McNeeley.