Isabel, 25, of Norwalk, CA
Length of Engagement: 4 years
The gain: "I had played sports through high school, but after getting injured, I stopped being as active. Unfortunately, I didn't change my eating habits. I was like a smoker with food—the hand-to-mouth thing was a habit. I was always nibbling on cheesy, salty snacks and never ate properly portioned meals. The weight piled on."
Her OMG moment: "One day I went wedding-gown shopping and was devastated when a size 12 was too small—and that was the largest size in the store."