10 Pounds in 10 Days: Can I do it? Writer Mary MacVean tried out trainer Jackie Warner's diet and exercise plan from her new book "10 Pounds in 10 Days." Here's her experience. Day 1 There are always new diet books out there. You've got to wonder: If we could make them work, would the publishing industry have to tighten its own belt a few notches? Day 2 I basically follow rules; it makes me nervous not to. But there's no way I'm going to drink just one cup of coffee each day - all that's allowed on Warner's plan. Day 3 Even though I didn't get to breakfast until a little late, my stomach was shrieking in outraged emptiness by the time lunch rolled around. Day 4 Jackie Warner has appeared in The Times as one of the fitness experts in our "Try This" feature in the Saturday section, showing various exercises. She is the definition of buff, while my upper body is more like the definition of undefined.