| Cutting out sugary drinks is great, but remember juice is an incredibly sugary drink (it's basically fruit without the parts that make fruit good for you).
Running is good. When it comes to strength training, don't just focus on a few things (like daily of pushups and crunches). Instead, get a well rounded routine that works all your muscles. Look around for program ideas, if you don't have access to equipment, there are also a lot of bodyweight exercises you can do.
Don't just try to go without eating, you need to eat every few hours, and make sure you are eating enough. Just make sure you eat the right things. | 
