Kim Kardashian is to sponsored Instagram content as Jennifer Lopez is to ... well, everything. In other words, she's really, really good at it, and she's been doing it for a long time. However, her latest Instagram ad appears to have landed her at the center of controversy, yet again.

The 38-year-old faced serious backlash from fans on Wednesday after she shared a sponsored post on Instagram promoting Flat Tummy Co’s meal replacement shakes.

In the post, the Keeping Up with the Kardashians star poses with one of the brand’s chocolate shakes, sharing in the caption that the drinks are “helping me get my tummy back to flat.”

The ad didn't go over well with the reality star’s fans. The comments section was quickly flooded with angry responses, with many people calling the shakes “dangerous” and claiming that Kardashian’s post was “deceiving” her 124 million followers.

“Dangerous and misleading! You should be ashamed of yourself, flogging laxatives to millions of impressionable young people,” one commenter said.

Another wrote, “People have stopped falling for stupid detox drinks and tea scams. Please!! Stop it! Start off 2019 by Not trying to deceive consumers with this garbage.”

Though, the beauty mogul’s fans weren’t the only ones who took issue with the post. British actress Jameela Jamil took to Twitter just hours after Kardashian’s post went up to write that the “diarrhea powder pushers are back out in full force pouting next to their laxative shakes,” along with a video shading influencers who endorse the weight-loss drinks.

But this is far from the first time that Jamil has criticized Kardashian's Instagram ads.

In May 2018, she slammed the star on Twitter for endorsing Flat Tummy Co’s “appetite suppressant lollipops." The Good Place actress screenshotted the beauty moguls controversial post, calling her a “terrible and toxic influence on young girls.”

So, is there any truth to these claims of danger surrounding Flat Tummy Co's popular line of shakes? To answer that question, InStyle spoke to Tracy Lockwood Beckerman, a registered dietitian in New York City and resident nutrition expert at Betches Media, over email about the risk factors associated with meal replacement drinks.

"These shakes are beyond dangerous to promote to society," she said. "Celebrities are endorsing a product to their impressionable fans that can ultimately cause unpleasant side effects in the body such as diarrhea, uncomfortable headaches and drastic shifts."

Beckerman explained that appetite suppressants are not only unhealthy for the body, but they "promote a false high where people may see results which may cause them to become addicted to these types of products."

So, yes there is a chance than you can lose weight by drinking a Flat Tummy Co shake — but don't expect it to last.

"Short term, if anyone removes a meal from their diet and replaces it with a low calorie shake, yes, they will lose weight temporarily. Key word, temporarily," Beckman said. "The day someone stops taking the Flat Tummy Co products, their natural hunger hormone, known as ghrelin, will return and often with a vengeance. This may result in subsequent weight gain due to the swift metabolic disturbances taking place in the body."

And that's not all! It turns out there is some truth to those comments about the shakes acting as a laxative, and it all stems from a special ingredient called Super Citrimax, which Flat Tummy Co claims makes their meal replacement shakes "3x more effective than diet and exercise."

"A common side effect to garcinia cambogia (aka Super Citrimax) is diarrhea and cramping, so I'd expect lots of people to be experiencing some form of GI (gastrointestinal) discomfort while taking this product."

Beckerman added that consumers should also be concerned about the other ingredients included on the rather lengthy nutrition label, particularly the level of Vitamin B12.

"They have unsafe levels of vitamins, especially Vitamin B12, which is extremely dangerous for the kidney to have to filter out from the body. I've never seen a food product on the shelves with 8,335 percent Vitamin B12, that is a big red flag."

"The amount of work the body has to go through in order to metabolize, digest, absorb and excrete over 80 different ingredients on their nutrition panel, seems exhausting and downright unethical," she continued. "Their ingredients are pumped up to distract us from the many holes in their company. There's two different types of protein powders and too many different flavor profiles and sweeteners to count," she said.

And these are just the short-term concerns. "Until research looks at the long-term results and long-term effects that this supplement has on the body, don't expect me to buy into this magical elixir," Beckerman explained.

Maybe stick to promoting makeup, Kim.