Extremist

So I just learned that I'm a diet extremist (not my word). Which means I always view my life as being on or off a diet. There is never any moderation. I'm either losing weight or slowly gaining. But I would like to be a healthy person and not always going from one extreme to the other.

I know (and am friends with) people who never seem to gain weight as they age. I find that strange. I guess I believe that over time, if you aren't dieting, you gain weight. How do these people remain healthy while seemingly unconcerned with their weight? And when I think about it, what is wrong with me that I don't really believe that someone can remain at a healthy weight without being on a diet? I think I need to spend some more time thinking about this - and figuring out where my thought process is faulty.