Whats the verdict to losing pure fat in the body? is it doing interval circuit training.. or eating right proportions? and what are good food to loes?

Unlikely: You can't lose "only fat". Whenever your calories-out is more than your calories-in, you'll lose some muscle mass. Anyone telling you otherwise is selling you something. You can limit muscle loss some by eating plenty of protein after exercise. The key to being really fit & looking & feeling good is finding a fitness activity that you enjoy. Best wishes.