Is it lifestyle or cooking method I need to change to lose weight? I don't eat out anymore.

Can be both. Depend on what lifestyle you are talking about-make sure you are eating regularly at least 3 times a day and not just one time a day.Or whenvever you are hungry. You can eat out but make sure choose the right type of food-not fast foods all the time. For cooking , try to bake or broil your foods and not to fry them., not too much high carb. And high calories foods as cheese, dairy etc....