While Ramsay acknowledged that public scrutiny was part and parcel of being a celebrity kid and in the public eye, she wrote that Allen's comments went too far.
"I'm so grateful for all the amazing opportunities I have been able to take part in and I understand that being in the public eye obviously comes with its own repercussions and I've been aware of this from a young age," she wrote.
"However I won't tolerate people that think it's okay to publicly comment and scrutinise anyone's weight and appearance."
The teen's Instagram was flooded with messages of love and support in response, with her fellow MasterChef contestants Ian Thorpe and judges Melissa Leong and Jock Zonfrillo among those to join the chorus.
"When Tilly came [to Celebrity MasterChef] we all just wanted to give her a hug – a 19-year-old girl on the other side of the world," swimming legend Ian Thorpe said.
"I just think that it is entirely inappropriate to be making comments about someone's weight in any way. I thought we'd got to a point where even making a positive comment on someone's weight doesn't seem all that appropriate either.
"I just feel for her."
Packed to the Rafters star Rebecca Gibney also voiced her support, writing that Allen "needs a good kick up the bum" and that "for that one dimwitted twat – there are millions who adore you".
Zonfrillo wrote that the radio host's comments left him "actually speechless", adding that he "should be taking a good hard look at himself, and good on you Tilly for calling him out".
"You're gorgeous Tilly, from the moment anyone meets you they are drawn to your warmth, energy and humour. You are generous and polite and someone your parents are super proud of. Stay focused on that, the rest is just noise with the intention to throw you off track."
Praising Ramsay's classy response to the drama and sharing her post, Leong said Allen "should be ashamed at your behaviour … you're not exactly a supermodel mate".
