Editor's Note: Here is what Damon said about losing the weight:
"I think the most challenging role that I've ever had, was when I did Courage Under Fire and I had to lose all the weight that I lost on my own. That was the most physically challenging did I've ever had to do in my life. I weigh probably 190 pounds right now, and I weighed 139 in that movie, and that is not a natural weight for me and not a happy weight for me even when I was 25. I had to run about 13 miles a day, which wasn't even the hard part. The hard part was the diet. All I ate was chicken breast. It's not like I had a chef or anything, I just made it up and did what I thought I had to do. I just made it up and that was incredibly challenging."