Rosie Mercado Lost 240 Pounds

Model Rosie Mercado went from 410 lbs to 170, but rather than celebrate her fitness ... she says people have told her to jump off a bridge over it.

We got Rosie at LAX where she reflected on her incredible weight loss. You can tell she's happy and excited about the change -- even though some of her fans do NOT feel the same way.

Check out the clip -- Rosie shared the crazy level of hate she's been getting. Seriously. You're about to see how mad people get over someone else's happiness. Translation: welcome to show biz.