Rosie Huntington-Whiteley wished her bottom was more toned.

The 30-year-old model - who has three-week-old son Jack with her fiancé Jason Statham - is a ''fitness fanatic'' and she has worked out intensely she know has ''really defined'' arms, although she thinks they are ''too defined'' and would rather have focused on exercising her derriere.

Speaking about her intense work outs and her body shape, the blonde-haired beauty said: ''I'm a fitness fanatic. It's where everything starts for me. I have really defined muscles in my arms, almost too defined, so I leave them alone completely. But I wish my bum had the same problem.''

And the catwalk icon has revealed she maintains her slender frame by eating ''clean, organic, simple'' meals, but when she meets up with her friends or 49-year-old beau she will let her hair down and enjoy whatever dishes she fancies.

She explained: ''At home, I eat clean, organic, simple. And when I go out with friends, I enjoy myself. Here at home, in the morning, I might have some boiled eggs or sprouts with toast, with a green juice. Or I might have some scrambled eggs with some spinach. Plenty of water through the whole day. And then at lunch and dinner, it's about a piece of protein: white fish, turkey, chicken. And lots of vegetables. Pretty simple.''

But the style muse ensures she is not ''restrictive all the time'' with her diet and will happily indulge in ''loads of roast potatoes'' because she believes a healthy and balanced lifestyle is ''important''.

Speaking to Prestige Online about her eating habits, the 'Mad Max: Fury Road' actress said: ''But, you know, then I'll go and eat dinner and have loads of roast potatoes at Madeo. And that's important to me. I love that. I couldn't live life just restrictive all the time. It's just no fun to me. That's not a way to live. It's all balance.''