If you want to change the way your body looks, calories will be super important to change your body composition.
You lose weight by creating an energy shift, and this energy shift is created bya difference in calories!
It is far easier to create this energy shift through your nutrition intake, than it is by exercising it off.
All diets, no matter which ones, work in the same way: they reduce the amount of calories you are taking in. Because you are taking in less calories than you burn, you are able to lose weight!
Example: if you eat 1500 calories and you burn 2000 calories, you have created a caloric deficit of 500 calories.
Does this mean I need to burn an extra 2000 calories per day?
No, you are already burning calories, even in your sleep!
1. You need to be in a caloric deficit to lose weight
2. You can do that through changing your food intake