Think of it like this: What words come to mind when you picture a movie theater? Popcorn? That's because you've linked the movie theater with eating popcorn. Eating to satisfy hunger is an appropriate reason to eat, while eating just because you're in a movie theater (or a room in your house) is not. These habits can seriously derail your weight loss efforts.
As important as it is to remember that your diet also plays an integral part in your plan of how to lose weight, one of the easiest ways to drop a few kilos is through exercise. You need to be able to achieve a balance between the two to get effective results. The exercises that you could perform during the week are resistance training exercises - such as weight lifting - which lead to a similar amount of weight loss as aerobic training. These will also help you add and maintain muscle mass and strength.