Letting Yourself Go

It has come to my attention that one of my friends, who recently got married, has already begun to "let herself go." How, you may ask? Well, gone is the long, styled hair, the average figure, the friendliness, and the positive attitude. It has been replaced with a kind of weird hairstyle that is never actually styled. The figure has somehow morphed into this thick in the middle trend, complete with a little ponch (did I mention there have been no children yet? why the ponch?) and her face has gotten fatter and wider. And friendly? Yeah right. She has major attitude now. She is very negative and is constantly complaining about something. It is really sad because while I used to enjoy spending time with her, I now can only take her in small doses.

This topic of "letting yourself go" got me thinking: why does someone let themselves go? Fear? Resentment? Laziness? And when does it start? After marriage? After kids? Anytime?
Please let me know what you think.

(And please, please, please, if I EVER start to "let myself go," for my own good, tell me. I'd like to think I take more pride in myself/my family/my life than that, but you never know...it has been known to happen to many a man and woman).