Jennifer Lopez says she's been a steady size six for the past decade and that you'll never see her looking like a waif. "I couldn't ever be a size zero," she tells the British edition of Elle in its May issue. "I just don't see how I could get down to that size and still be healthy. "It wouldn't work. I have a butt, I have boobs and I have a woman's curves; there is no way I'd see them go to zero. I hate to look in a magazine and see a picture of a girl who looks so thin she looks unhappy and as if she just needs someone to give her a good meal." Lopez, 37, continues: "There are girls out there who are naturally thin and who look great, but it's got to the point where models are dropping dead on catwalks because it's all about being thin. It's insane." Other celebrities, including Claudia Schiffer and Kate Winslet, have spoken out against the trend among models and actresses to be dangerously thin. In recent months, several models have died from anorexia, including Brazil's Ana Carolina Reston, 21, who died in November. Lopez can understand the pressure: She says that in Hollywood, "I've always been seen as a big girl. "But I like my body. My husband [singer Marc Anthony, 38] likes my body. And for most of my adult life, my body hasn't gone up or down, it's remained the same, give or take four pounds. I'm not obsessive. I work out with a trainer two or three times a week, but I'll go months at a time without any exercise at all. I just keep myself in check." What does that mean, exactly? "I eat meat, I eat carbs, I even eat McDonald's. What I don't do is ever overeat. I don't eat desserts and I can limit the chocolate chip cookies to one or two." She says if she puts on a few pounds, "I feel it immediately and I just get a bit more strict with myself." Her best tip: "For me, looking good is all about looking healthy, and the ultimate beauty secret is about being happy in yourself."