I would say the best exercise is cycling, its so much more enjoyable than being in a gym. I started cycling because i couldnt afford a car anymore but then realised i prefered it! It was painful for the first few weeks as you use different muscles i guess but if you carry on i'm sure you'll loose weight. Its hard to not eat the junk but if you dont already then cut out all processed food, like ready meals and frozen food, also fizzy drinks (even diet ones) or squash. have water or fruit juice. Snack on things like fruit, natural yoghurt, raw veg, nuts and seeds, rice cakes. make your own soups and smoothies. But not just for a while, eat like this forever! Good luck