Irina Shayk -- I EAT LIKE A FATTY ... 4 Burgers In One Night

File Under: "Yeah, right ..."

Smokin' hot swimsuit model Irina Shayk says she ate THREE burgers at the Vanity Fair post-Oscars party last year -- and this year, she was gunning for FOUR.

So ... you buyin' that?

BTW -- directly after making the statements, Irina went on the red carpet in her half-naked outfit and showed off the body that gorging on burgers built.