I've run multiple marathons in my life. When training and running > 20 miles / week, I could eat anything I wanted and still lose weight. I usually stayed around 170/lbs - about optimal for my frame. It didn't matter what I ate, and I've heard stories of people who just ate cheesecake or some such due to the calorie load.

Unfortunately I can no longer run and have since ballooned up to 200lbs.

You can definitely out-train a diet, it's sustaining it that's hard.