Photo: J.R. Mankoff (left), Jason Hornick (right)

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Kerri Castellini, 30
Washington, D.C.; Attorney

Before:                After:
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."