Jennifer Lopez is ''terrified'' of plastic surgery.

The 44-year-old singer, who has six-year-old twins Max and Emme with her ex-husband Marc Anthony, admits she'll do ''whatever it takes'' to keep her enviable figure in tip-top condition, but she insists she'd never go under the knife to maintain her youthful looks.

When asked if she'd ever have cosmetic surgery, she replied: ''I'm terrified of anything like that, like going under, I would be like, 'No, don't put me to sleep.' ''

The 'On the Floor' hitmaker admits she has to work hard at achieving her famously shapely derrière, but she believes anyone can do it if they workout and eat healthily.

Speaking in an interview on the Jules, Merrick and Sophie with Mel B Show on Australian radio station 2DayFM, she said: ''[You can achieve a good butt with regular upkeep] little by little - as opposed to letting it get away and pulling it back with a knife. I think you can do it with eating healthy things and working out ... I've always been quite an athlete. From very young, I used to run track and do tennis. For me, it's always about getting into the gym or getting out there and just running outside - whatever it takes to kind of just, keep it all together. I think you can do that with good...you know, eating healthy things and working out, and you don't have to go crazy, you don't have to be a fanatic but just upkeep little by little.''

Despite her determination to exercise and main a healthy diet, she admits she sometimes has days where she feels ''fat'', but deals with it by dressing to suit her mood.

When asked if she has 'fat days', she said: ''Oh yeah, oh my God yeah, I mean and I dress for ... you know, when you have those days, you dress for those days. Like, when I wear the really loose ... it's like, maybe we should just wear kind of a tent dress today - but, make it cute.''