At my heaviest I was 280lbs with 35%+ bodyfat. I found a diet that my body responded well to and stuck to it, within 6 months I lost over 30+ years of bodyfat doing nothing but solely focusing on diet. I did absolutely zero exercise and lost 71 pounds and 25% bodyfat in 6 months. I began weight training again after taking 3 years off in January 2015 and have been consistent since then, 5 months later I've gained all of the muscle, but none of the fat back because I stayed on this diet. That's how you lose weight and keep it off, you concentrate on diet FIRST.