Yes, and people think that by taking "more" of this and less of that, or adding this that or the other thing to the regimen, then they will find the magic key.
BASICS. Diet, exercise, fresh air. And no, Cougar, I'm not singling you out because I don't know. I HAVE seen that mindset in action here though, numerous times.
You can't get healthy and maintain that doughnut habit. It just doesn't work. I know this is true because I just got dough-nutted by DH this winter, and my health suffered.
I used to be able to eat and do ANYTHING. Aaaaah, lost youth!