Actually, an increase in protein doesn't necessarily mean a huge increase in calories. Trust me, you have to eat a TON of grilled chicken in order for it to be a substantial caloric intake. And yes, you have to build muscle to burn fat, and protein will definitely help with that. The key is replacing something you're already eating with added protein. Cheese and eggs are fantastic sources of protein. Don't put too much stock in the "fat" count. Your body needs fats just like it needs carbs, and things that are low-fat are actually worse for you than regular-fat foods. Low-fat foods are overly processed in order to get the fat out, which also means they lose a TON of their nutrients in the process. You're better off overall eating regular-fat foods because your body will process and burn those much more easily, and you'll get the full nutrients from the food. Also, with a protein increase, make sure you increase your fiber, too. Add in Benefiber or something similar to your diet. Even with lean proteins, your body can easily get backed up when you increase protein, so you can be retaining a lot of bloat and weight despite eating better. It's important to keep your fiber up in order to regulate the increase. You also want to make sure that you're consuming your protein at the most effective times - generally right after a workout is ideal, so that your muscles can use that protein as they recover from the workout.