So many of the choices I make about living my life are partly to mostly motivated by the sense that I don't want to be that person. Une femme d'un certain age explains why she won't diet:
If I could harness all of the wasted energy I've spent dieting/regaining/agonizing about my weight over most of my five decades of life, it could probably light up Times Square for a year. A few days ago, Duchesse linked to an article from Harpers in 1993, The Weight That Women Carry. In it, the author, Sallie Tisdale says "What I liked in myself seemed to shrivel and disappear when I dieted." That one sentence sums up why I'll never darken the door of Weight Watchers again, or sign up for the "Lifestyle Change*" du jour. Ultimately, I don't like the person I'd have to be to look how I'd like to look. (That person is obsessive, self-involved, self-righteous, anxious.) (links omitted)
I've noted similar problems with people who are obsessed with physical fitness (not just diet, but exercise too) as the path to a good life. There's a degree of one-true-way-ism to most of them (this worked for me, so it must be the way for you) and the self-righteousness that says "I did it, so if you don't, you're not trying hard enough." Neither recognizes the differences among people's capacities and choice fields; neither recognizes the limits on what we can affect through our choices. (While we always have a choice, it isn't always a useful choice, one that affects the outcome; the possibilities don't always include a good option, a choice that makes things better.)
Means and ends both matter.