Undav is currently with Germany at the Euros after a superb season on-loan with Stuttgart.
Speaking with the Stuttgarter Nachrichten, Undav admited as a youth player he was 'a bit chubby', which caused a coach to axe him.
Undav says that it was kebabs that cost him a place on the Werder Bremen U15 team.
"I grew relatively late and was a little chubby because I ate a little too much kebab. As a result, I failed to make the U15 team.
"The coach told me that it would be better if I looked for a new club. 'I need big players, you are too fat for me', he said.
"It was like a slap in the face. I joined the club with the ambition that I would become a professional – I wanted to make my family proud. But that's just how it is sometimes in life. You have to get back up and I did.
"I still like eating kebabs, but I make sure I don't eat too much junk food during the week."