Well, that's a lot..
Drink a lot of water;
don't eat fried stuff;
don't have candies;
don't have things that have sugar (like yoghurts with sugar.);
don't drink alcohol......

First thing, dont look at it as loosing 140 lbs. Look at it as I am going to loose 2-3lbs. In 2 weeks, make a realistic short term goals because if you say " I wana loose 140lbs. And it just seems so far away and then u just feel unmotivated because loosing weight takes time) anyways to loose weight and keep it off.... Diet and exercise. And its more mental than anything you need to want to do it, and make it apart of your life and want to do it. Be extremly motivated and get others to motivate you too, like go to the gym with friends. There's no other way to loose weight and keep it off except diet and exercise good luck!

i completely agree with laura: making realistic goals is so important here. And then, baby steps :d

When I started atkins/low carb 10 years ago I lost 100lbs in the first 6 months so it is doable at a stretch, you maybe need more like 8 months, I would highly recommend low carb as the way to go, it is healthy, nutritious and, with a little work, very versatile.