Weight and health are very complicated. I'm in my 4th year of medical school and still struggling on figuring out how to educate my patients. But to keep it simple: ignore BMI. Pay attention to the waste line. For men get into the low 30s. Work out a bit every day. 30 min daily is better than 3 hours once a week. Cook more at home. Decrease your intake of processed foods and non whole grains. Get support. Have fun. Move. Celebrate the small success. I offer up myself if anyone would like to discuss nutrition from a medical perspective. Personally, I do a high good-fat, protein, low grain (high veggie/fruit) diet. Med school got me up to 250 at 6'7". I'm now 210, running, training, lifting, and on fitocracy. The best data we have right now suggest the specific diet doesn't matter, so find something that works for you.