I was up to 215lbs (5'9") at age 30 and just couldn't take it anymore. Logged too many hours compressing seat foam in front of a computer at work with too much partying and drinking at night.
Went on a lower carb diet and started to run everyday. Lost about 30lbs right away, just fell off fast. Then lost another 30lbs after that. I now run and/or bike almost everyday and I have hovered around 155lbs for over two years. My first marathon is in a month and I ride centuries almost every weekend.
If I can do it, anyone can.