Khloe waxed poetics about Kim's figure as well, telling her she looks like "a walking FaceTune doll" — in reference to the FaceTune app, which enables people to edit and enhance their appearance in pictures.
Kendall then held up her bite-sized black purse, telling Kim: "My purse is as tiny as you."
Kim prompted her sisters to keep commenting so she could record their comments on camera.
"I've never seen a skinnier person in my life," Khloe said. Kim responded: "Well, you have, because I'm looking at one," in reference to Kendall.
Khloe replied that the model's lean figure is "natural", telling Kim: "You, it takes work to look like that and that's amazing."
She and her friend Malika Haqq, 35, joked that Kim survives on "celery" and "different flavors of oxygen".
"You guys, I'm not that skinny!" Kim exclaimed. "I'm down to 119 pounds. I will say when I take out my hair extension I am less."
Khloe then said of her sister's silhouette: "But she's anorexic here [points to waist] and her arms are like pin thin, they're like my pinkie — it's bizarre."
The exchange left social media users outraged and worried that Kim, Khloe, Kendall and Malika's comments could perpetuate eating disorders and have a negative impact on Kim's youngest followers.
Some pointed out that Kim has a whopping 114 million subscribers on Instagram, and as such holds considerable influence.
"Listening to @KimKardashian, @KendallJenner and @khloekardashian use words like "anorexic" and "skinny" as a compliment makes me SO sad and disappointed," one person wrote. "You have young children around you and millions of followers. Please don't influence and encourage eating disorders!"
"Kim Kardashian being obsessed with her sisters telling her she's skinny and that she looks anorexic on her Instagram story makes me sad," another person added. "It's so harmful for young women to hear that message, they are supposed to be role model, not encouraging themselves to lose weight."
"Saw a video where Kendall Jenner tells Kim Kardashian that she looks like she never eats and that she's concerned about how skinny she is. Kim K says "thank you" in the most delighted voice," someone else tweeted. "Like, do they ever get tired of being so problematic?"
The uproar comes just two months after Kim was bashed for advertising appetite-suppressant lollipops on Instagram.
Her post, which she has now deleted, prompted backlash from many people accusing the reality star of promoting disordered eating habits by advertising the product.
As it turns out, there is only one published study on the lollipop's active ingredient, which was performed in 2010 by a French researcher at a low-profile pharmaceutical company on the outskirts of Toulouse.
