'You gotta lose 15 pounds,' she recalls the infamous Sony Music boss telling her, when she was called in to sing for him.
She says he continued, 'That's what it takes to be Jessica Simpson.'
Jess, now-39, said at the time, she weighed just 53kg.
She then began obsessed over her weight, which saw her plummet to just 46kg.
For the 'next 20 years,' the I Wanna Love You Forever singer used diet pills in an attempt to keep her weight down, which also resulted in hallucinations and a lack of sleep.
So, she started taking sleeping pills, too.
'I started hearing voices when I was alone at night, waiting for the sleeping pill to kick in "Do more sit-ups, fat ass,"' she recalled the voices telling her.
'Freaking hungry', Jess said she eventually reached the weight Tommy wanted her to be by the release of her second album in 2001, but was then forced to 'show more skin.'