Well the thing is, you don't want to lose weight, you just want a tighter thinner body. Muscle weighs 2.94 times as much as fat. Granted you should cut out fatty foods and such, but the key is to exercise. As you exercise, your body burns off fat, and uses it to create muscle. Your body will take a nice shape, be thinner, and you will be stronger. The thing about this is you will weigh more because, as I said, muscle weighs more than fat. Keep in mind, reduce fatty foods, but don't cut them out completely. Your body needs a little bit of fat to keep running. Fat provides you with energy when your body is under extraneous conditions. Anyways. The key for looking good for the summer is exercise. And don't do light exercises like jogging either, do hard exercises like bench pressing weights.