weight training, weight training, weight training. i came to college at 6'7", 250 and by november i was 210. i was in the best shape of my life, i gained a lot of strength while eating healthy. it's possible to lose weight fast and still do it in a healthy way - since i was fat, i found it very easy to lose the weight because muscle uses so many more calories. swimming is also great, it's a tough workout but its a lot more fun than running imo