I read an article about some aborigine tribes that were traditional hunter/gather. The article states that even though they burned way more looking for food the daily burn was still in the 2000-2500 range for men. The article suggests that the reason for this is during their down time their bodies use less energy to compensate. Basically humans no matter what burn approximately the same amount within certain standard deviations. Working out like crazy sure can make you healthier than someone who sits around all day and the overall appearance would be better. That isn't the way to lose weight though there was only a 10-30% increase in calories burned so even if the treadmill says you burned 1000 calories during a run your body probably conserved as you sat dead on the couch afterward. 10% on 2000 is say 200 calories actually burned above normal when you see 1000 on the workout machine.
The real way to lose weight and keep it off is 100% basically how you eat and not the working out part. Sure muscles burn more calories than fat and you are healthier if you workout but you can't achieve long term success by working out and still eating fast food every day. I can't follow it myself I eat pizza 2-3 times a week it seems like but basically you have to eat veggies and healthy food or it wont matter. Some of the super hero actors/actresses (not those who bulk up like 4500 meat diets) do a 80% uncooked veggie diet and 20% eat what you want sort of thing. So get to 1700 or so calories on raw carrots, celery, broccoli, whatever (can mix in lean protein, egg, brown rice, etc in this part), and 500 calories of what ever you want in a day. If its unhealthy you really limit yourself to a serving of doritos and a slice of pizza. If you think about that in the grand scheme when you probably normally eat 3-4-5 slices of pizza at one sitting then it makes sense you'd lose weight that route.