At first, it looked like just another selfie from the camera-loving Kim Kardashian.

But Kim’s latest Instagram post has found the star in hot water with fans, who have accused her of sending a “damaging” message to young girls by promoting meal replacement shakes.

Posing in activewear and holding a shake in one hand, Kim claimed she was taking the weight-loss product to give “me a kick in the right direction” after Christmas.

“These meal replacement shakes are so good and they’re helping me get my tummy back to flat. I’m already feeling amazing and I’m so excited for the next few weeks,” she said.

An error occurred while retrieving the Instagram post. It might have been deleted.

“Because they’re all about getting women back on track … they’ve got a 20 percent off sale going on right now, so if you want to start 2019 off right … trust me, you’re going to want to check them out.”

But fans weren’t keen to take Kim’s advice on the product, with her post instead attracting more than 17,000 mostly negative remarks.

Furious commenters accused her of promoting an “unhealthy and dishonest” product and questioned whether Kim would give the shakes to her three children.

“SHAME ON YOU! What a damaging post to so many young girls that follow you and look up to you,” one disgusted person commented.

“How much did you make off of this? @kimkardashian,” one follower asked.

“You really have no shame, do you? Or any acknowledgment that young women are impressionable. Shame on you,” another fan wrote.

An error occurred while retrieving the Instagram post. It might have been deleted.

But the backlash over Kim’s post didn’t deter her older sister Kourtney Kardashian, who posted a similar promotional photo for the brand on Instagram just hours later — which also attracted negative comments.

It’s not the first time the Kardashians have come under fire for promoting products from Flat Tummy Co.

Last year Kim was forced to delete a post spruiking the brand’s appetite-suppressant lollipops after a mountain of backlash.

Criticism against celebrities promoting weight-loss products on social media is being led by "The Good Place" star Jameela Jamil.

Jamil, who has admitted to falling prey to “miracle” weight-loss products as a teen, tweeted in November that she hopes stars who spruik these products “s--- their pants in public”.

This article originally appeared on news.com.au.