The Today show discuss the warning note a mum received from her child's school over 'bad' food in lunch box. CREDIT: TODAY show/Channel 9

A mum has been left “disgusted” after discovering a “horrible” message from her son’s teacher scribbled on a note in his lunch box.

Francesca Easdon wrote a cute message to her son Kyler telling him she loves him and placed it inside his lunch bag. But when the young boy returned home, Ms Easdon was shocked to discover one of his teachers had scribbled their own message on the piece of paper, telling the mum to put her son “on a diet and go away”.

After making the shocking discovery, the mum from Texas in the US shared a photo of the awful find on Facebook, and people are furious.

“Of course I was absolutely livid and immediately reached out to the school,” she wrote alongside a photo of the note.

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“I am disgusted that I put my trust in these people to care for my child and this is what I get in return. I have removed Kyler from this daycare and am enrolling him in a beautiful new facility.”

She went on to explain that the school had fired the teacher involved, but she was still concerned about her son’s safety.

The sweet note Ms Easdon had popped in Kyler’s lunch box on Thursday read:

“Please tell Kyler that his mommy loves him so much and I’m thinking about him.”

But when he returned home, she found an added scrawl at the bottom that said: “No! Put him on a diet and go away!”

“I sent this note in Kyler’s lunch box, thinking that it would make him smile at lunch time,” Ms Easdon explained, adding she had been introducing “new healthy options” in his lunch box, but her son was “extremely picky”.

“I feel that Kyler is absolutely perfect the way he is, I’m just helping him make healthier choices. Instead of his school being supportive, I am in absolute shock at what happened,” she said.

Friends and family on Facebook have rallied around Ms Easdon, calling the incident “appalling”.

“I cannot believe a teacher would write something like this. It is appalling! Your son does not even the slightest bit need to be “put on a diet”. And even if he did, writing a note like that is immature, inappropriate and just ignorant,” one said.

“I cannot believe a grown adult wrote this back to you!?” another said.

Another wrote: “You handled this so well. I can’t believe a grown adult would act like this.”

In the comments, Ms Easdon described the situation as “horrible” but explained her son was unaware of what was going on.

“I just told him we are moving up to a better school and he’s excited,” she said. “I’m ready to put it behind us and get Kyler a fresh start.”

Continue the conversation @RebekahScanlan | rebekah.scanlan@news.com.au