Kerri Castellini, 30
Washington, D.C.; Attorny
Dress size: 12 Dress size:10
BMI: 30.7 BMI: 28.3
Weight: 168 Weight: 155
Her Favorite Snack
"Apples and peanut butter. The healthy fats in peanut butter make me full quickly, so it's great before a workout."
Her Reality Check
"I take a weight-lifting class at my gym once a week, where I check my form with the instructors. That way I know I'm not cheating when I'm on my own."
Her Backup Motivation
"My coworkers know I'm trying to eat well, so if I order a cheeseburger for dinner, I get funny looks."
Her Best Advice
"Take a couple of hours on Sunday to plan your meals for the week and make as many of them as you can. When you're busy, it's safer to grab a balanced meal from your freezer than to let hunger dictate what you eat."
Photo: J.R. Mankoff (left), Jason Hornick (right)