BMI on athletes and body builders is invalid and applies to a tiny fraction of people. A normal person with 30%+ BMI? The OP was right, but mean about it.
At one point I was 50 pounds overweight, gained it all in college.
I lost it all in 4 months by changing my diet to a healthy one( for example oatmeal/eggs in the morning a very healthy smoothy for lunch - berries, pomegranate, acai, beet, kale, lemon and other juices- and chicken/fish beans/brown rice/quinoa and a large salad with good lettuces and lots of different vegetables and fruit with nothing else for desert - I spend less than $100 a week on food for 2 people) and without any exercise. I still had my daily blue Full Throttle as my only vice. I did it during winter and where I live it is too cold and icy to go running.
I cut out lots of sugar and simple carbs, very little pasta and potatoes and no sodas. Once a month I would have a grilled chicken salad and fries with no soda at Wendy's as my "cheat" meal.
I kept it up and am maintaining a healthy weight and am out running a few times a week now that it is warmer.