The four girls took time off school to appear on the ITV daytime show, wearing glossy lipstick and glamorous wigs to discuss the body shapes of celebrities.
But the show has been accused of humiliating and objectifying the children, according to the Mail.
During the Friday feature, entitled 'little women quiz big boys', the girls were dressed to resemble the show's regular presenters and read out scripted questions.
One little girl quizzed Ant and Dec about their on-stage encounter with Kim Kardashian at the Brits last week and asked: "How big is her bum?"
Ant jokily replied: "That was the biggest topic of conversation. Is it real, is it implants? It's fascinating. It's because she's so thin in the waist and her legs are thin."
Then Dec chipped in: "To be honest, I didn't look. I was too busy looking at her boobs."
There weren't any viewer complaints to ITV about the risqué episode and a spokesman for Loose Women defended the girls' appearance, saying: "The children were actors and were given permission by their schools.
"Each child was accompanied by a parent or guardian. The children and their parents or guardians were happy with the questions, which were agreed in advance."
But Camila Batmanghelidjh, chief executive of charity Kids Company, told the Mail: "For the children it would have been a difficult experience, even though they may have appeared to have gone along with it.
"In effect, it's turning the kids into objects in order to deliver a joke.
"It is an adult joke and the children are being used to deliver something which is essentially adult humour.
"It's poor judgment to place the children in that kind of environment in front of such a wide audience. In the world of children, body scrutiny has become a big problem. Children are very coy about these things.
"They find it very difficult and they struggle to even go there. I am surprised no one thought this through properly."And broadcaster and psychologist Oliver James said: "A commentary about the desirability of a woman's body is not appropriate in front of children."
But comments on the show's Facebook page were divided.
Aimee Phillips wrote: "Shouldn't they be in school? Us parents get fined if our kids are off school. SHOCKING."
But one of the children's parents, Katie Bee, hit back, writing: "My daughter is still very much a 'child'. She loved it and is already asking when she can next go on TV."