Britney Spears works hard for her envy-worthy abs, as she regularly documents her insane workout routines on Instagram. But the icon is just like the rest of us, and enjoys the occasional junk food binge.    

Spears discussed her health routine on the road with Entertainment Tonight  recently, as she is about to embark on a 51-show North American and European tour.     

"Sometimes I'm just like, 'I want a hamburger!' but when I'm in work mode, I want [to eat] very clean. I want clean chicken and veggies that's it," she said. "My stomach is so sensitive, if I have a steak, I will be sick for three days."    

"The burger is fine, but I have the small burgers from McDonald's. The happy meal!" she added.    

Her Piece of Me tour kicks off July 12 at National Harbor in Maryland.