The actress, looking bronzed and super fit on Kimmel's chat show, told her host that while travelling the world promoting her movies the 'whole purpose for me is to eat in my favourite restaurants'.
'Do you really eat a lot?,' Kimmel asked. 'Because I find that hard to believe - because I eat a lot and this is what happens,' he added, joking about his own weight.
'Yeah I eat a lot Jimmy - but I also exercise. Wait a minute do you want me to write that down?'
As Kimmel pretended to take notes, Cameron said: 'Yes, eat as much as you want - and exercise.'
Cameron said she was obsessed with truffles - and met a farmer who had 'I swear, like, 300 truffles in the refrigerator'.
'Of course that's when I asked him if he needed a wife - I was pretty sure I had found heaven and he was the man for me. Until his wife tapped me on the shoulder and said, 'I got there first',' she said.
She also told him she was wary of her love for playing golf, comparing it to 'crack cocaine'.
Asked if, as such a big golf fan, she has ever met Tiger Woods, Cameron grinned: 'I have not met Tiger Woods.'
'Good,' Kimmel joked. 'Be very careful.'