I know Nicole Richie lost weight a while ago but she seems to have kept it off and had a healthy baby recently

How did she lose all that weight? I'm sure it's doable... how does one actually restrict her calories to 1200ish a day and exercise and work all day? Would you say it takes discipline? hypnotism? hoodia? I want for my health and my wardrobe. If you know a fabulous hoodia brand, please p it on. I workout already but need to do it more intensely and any tips on how this chic lost all that weight would be helpful! Thanks.