It's the other way.

When you eat more than your energy consumption rate, you're less hungry. When you eat less, you're more hungry. You think the activity would stop you getting obese, but it's actually that you aren't hungry enough to overeat, despite high activity.

I'm not overweight, never mind obese. I pay no attention to diet or exercise. If I'm really hungry one day, I can end up overeating something I quickly deep fried from the freezer. And then I barely eat the next day. Not consciously. I'm just not hungry for a long time after I overeat.

Energy homeostasis is the big thing you're not accounting for. Excercise doesn't really do anything much for your weight, just your fitness.