The reality TV star on Tuesday shared a since-deleted photograph of herself sucking on one of the lollipops marketed by a US weightloss company, which she described as "literally unreal".
The backlash was immediate, with fans criticising Kardashian in the comments for promoting "such an unhealthy approach to weightloss".
"This is disgusting," wrote one. "Your fans are going to be seeing this and thinking that this is how to get your body. Eating is good for you, stop convincing people to literally starve themselves of food to get a flat tummy."
"The Good Place" star Jamil assailed Kardashian on Twitter, describing her as a "terrible and toxic influence on young girls" and telling her to "f**k off".
"I admire their mother's branding capabilities, she is an exploitative but innovative genius," wrote Jamil. "However, this family makes me feel actual despair over what women are reduced to."
Jamil later fired off this second tweet:
Other people echoed Jamil's concerns, condemning the message Kardashian appeared to be sending:
The lollipop company's website says its lollipops contain "satiereal" (an extract of saffron stigma, which it claims "helps control food intake, cravings and weight) and are "designed to help you suppress your appetite".
"So with 1-2 pops per day, you'll have your hunger under control and cravings in check," promises the company.
The manufacturer had not returned HuffPost's request for comment at the time of publication.