Diffusion.
diffusion acts passively, and the oxygen and carbon dioxide move to the area of lower concentration
Energy homeostasis ..........
I believe obesity is the lifestyle that is more substantial of the 3 because, a smoking habit can be terminated and physical inactivity doesn't always mean the person isn't healthy. If they're not healthy, they can change that by becoming more active. If you're obese, you're most likely at a weight where it could be dangerous for you to just get up and go for a run out of the blue. Obesity, which can also lead to diabetes, is a tough thing to live with. If it's generic and not even their fault, but that person doesn't prioritize working out and making sure it doesn't affect them, it's going to end in obesity for them.
