Pop star Lady GaGa was hospitalized six times last year because of her yo-yo dieting, claimed the star's ex-tour manager.
The claims emerged in new book Poker Face: The Rise and Rise of Lady GaGa, by Maureen Callahan.
David Ciemny said the "sick" chart-topper went on crash diets after gorging on crisps and cupcakes.
GaGa reportedly admitted she had not eaten for weeks so she could squeeze into the gear.
"When I say she was sick, I mean physically and mentally," the Sun quoted Ciemny as saying.
Ciemny also claimed GaGa sacked 150 staff members during his 18-month stint as her tour manager in 2008 and 2009.
He said she did not think they were up to scratch, adding: "Everything had to be perfect."
GaGa caused a storm last month when she admitted she occasionally used cocaine, claiming it helped her creativity.