They’re chonky, they’re fluffy, they’re thicc and body pawsitive. They’re round boys, floofs and absolute units.

The new animal trend on the internet celebrates the rotund and plump, with social media users focusing on the adorableness of a cat’s rounded cheeks, a hamster’s many rolls, a dog’s rounded shape and a raccoon’s voluptuous volume.

The Instagram account Chonky Animals has more than 409,000 followers while the Round Boys and Round Animals accounts top out at more than 455,000 and 487,000, respectively. The Facebook group, This Cat is Chonky, has more than 395,000 members and hundreds of new posts each day.

The trend raises concerns about overfeeding and keeping a pet unhealthy for the sake of cuteness. While humans can decide if they are healthy at every size, animals cannot, nor do they have the ability to tell their owners if they need help. But it has also inspired a wholesome movement toward making sure these animals remain healthy, as well as cute. More and more accounts are now dedicating themselves to specific chonky cats – and their weight-loss efforts.

“A heavy cat is pretty adorable,” said Mike Wilson, one of the owners of Bronson, a cat who was 33 pounds when he was adopted and is now 23 pounds, one year later. “A big cat on a diet is a guilt-free way to follow an obese cat.”

In addition to Bronson, who has more than 214,000 followers, there’s Bruno Bartlett, the gray polydactyl cat that likes to stand on his hind legs, and his brother, Carlo. On Facebook, Fat Laila’s efforts at fat camp are lovingly documented, as well as her missteps – when she snuck into the closet to steal treats one night.

He was so adorable, but he could barely move Lauren Paris

“There’s a reason why the internet is so obsessed with fat cats,” said Lauren Paris, the owner of Bruno and Carlo. “They’re so cute.”

Paris felt drawn to Bruno when stories about a “thicc” cat up for adoption went viral last year. She and her friend wrote a song, Give Me That Fat Cat, ensuring not just the adoption, but Bruno’s Instagram stardom.

However, upon meeting him, she knew his claim to fame – his chub – could not stay.

“He was so adorable, but he could barely move,” Paris said. “The shelter was doing the best they could do, but he lived in a room with other cats and he would just eat their food.”

Facebook Twitter Pinterest Bronson has now slimmed down to 23 pounds. Photograph: Courtesy of Mike Wilson

Because Bruno was already so public, his weight-loss journey became public as well. Paris posts when Bruno loses a pound, along with tongue-in-cheek hashtags such as “real cats have curves”. She posts pictures of him gazing longingly at human food, or meowing in the background to cooking bacon.

“I’m not going to lie, I think fat cats are cute, but not so cute that they shouldn’t be on a diet,” Paris said. “Bruno, we look back at old videos of him and we think, ‘oh he’s so cute,’ but he’s really cute now and he’s going to live a lot longer. That’s way better.”

Wilson and Bronson’s other owner, Megan Hanneman, felt the same way when it came to Bronson’s health. When they met him, he had to lie down to eat. “He just looked like a giant swollen ball,” Wilson said.

“He was three years old and he weighed 33 pounds,” Hanneman said. “The standard cat weighs like nine pounds, so he was about the size of three pretty large cats at three years old. He couldn’t move around.”

Bronson used to cry for more food before Wilson and Hanneman switched him to a wet diet that was less caloric but more filling. Even worse was when he would cajole them awake for feedings. “At 3 in the morning, he’d come over and lay on us and purr in our faces,” Hanneman said.

Fat cats are cute, but not so cute that they shouldn’t be on a diet Lauren Paris

They enjoy posting about his weight-loss journey because cat weight loss is difficult. If cats lose weight too quickly, they can develop fatty liver disease, and typically sleep 18 hours a day and are hard to exercise, said Shari O’Neill, the chief shelter veterinarian at the San Francisco Animal Care and Control. Cats are also grazers, so it’s hard to measure out how much food they need to get through a day.

“It’s been a lot of fun sharing tips on losing weight and things we’re doing with Bronson, knowing that a lot of people have this issue with their cat, even if it’s not that extreme,” Wilson said.

But as with anything on the internet, there are trolls. “We’ve seen it all,” Paris said. “We see, ‘You’re abusing this cat’. We also see, ‘I miss when Bruno was fat’.”

Some of the top rules in the Facebook group, This Cat is Chonky, include no chonk-shaming, no owner-shaming and don’t do politics or medical advice.

“People see a picture of a fat cat and they think we made it fat,” Paris said. “Or when we just started to show his weight-loss photos, people who don’t know anything about cats will say, ‘Oh, he only lost two pounds? Well he should have lost more by now.”

She continued: “You don’t know why a cat is fat. You don’t know what diets have been tried. You don’t know if it has diabetes or not.”

In between cute pictures of Bronson and videos of his monthly weigh-ins, Wilson and Hanneman also post about adoptable cats around the country that are largely overweight, something Paris thinks is a much-needed effort.

“Something that’s good about this internet trend is that it does draw attention to these pets that would be passed by traditionally,” she said. “All of these famous chonky cats came from shelters. I think that shines a really good light. Kittens are more likely to be adopted, but if these internet-famous chonky cats are more likely to get adult cats adopted, then we did our jobs.”