Karen,
I'm not sure if I'd be considered a yo-yo dieter since my weight hasn't exactly yo-yo'd, considering that I've never had any major weight loss due to diets, although I've tried lots of them.
Let me start off by saying I'm female, 51 years old, 5'7" tall.
There was a time during my younger years that I did diet pills and lost tremendous amounts of weight, but I gave that up over 25 years ago.
In my twenties I weighed about 140-145, but during pregnancy I went up to 180 with my first, and over 200 with my second child. Since then, my metabolism seems to have changed. After my children were born, I was able to get some of it off (which included injections of sheep urine or some such oddity that was the trend at the time), but never back to my pre-pregnancy weight. Since then, I seemed to gain very easily, and over the years it got harder and harder to lose.
As my weight slowly increased I adapted, thinking it was an age thing, and so I adjusted to 155 in my thirties. I have some pictures where I looked pretty good in a bathing suit at that weight. However, it wasn't easy, but the time, I was doing Overeaters Anonymous, and it seemed to help.
Still, over the years I continued to slowly increase. For many years, I stayed around 160, but had to work hard to do it. I tried fasting, macrobiotic, vegetarian, vegan, low-cal, tomato soup, and others, mostly out of desperation to lose a few pounds, but usually gave up after a short period of time without any significant weight loss. Although none of these actually helped me lose weight, they helped me keep it at a manageable level, but even that manageable level seemed to move upward all the time. I would have liked to have gotten back to the 155 at least, but just couldn't get below 160 for a long time, and came to more-or-less accept that weight too.
So, between the weight loss attempts and eating fast food and microwaved quickies (I never seemed to have the time to cook healthy meals for myself, (although I would cook when my adult children visited), I kept my weight fairly steady at about 160-165 for several years while in the US. I convinced myself that this was my normal weight due to genes, and that I was destined to always be overweight.
Then, in 1999 I went to Estonia, and it all went to hell. There were no fast foods and no microwaves. There wasn't enough produce in the stores, mostly high fat/high carb foods, sausages, smoked meats, potatoes, dark bread, and boy, did I fall in love with that Eastern European beer! Over the past two years my weight increased to where it eventually ended up at 190. I was now depressed, feeling horrible, hopeless, and directionless.
While in Estonia, some of the diets I had used (other than fasting) in the past, were out of the question, because I simply couldn't get the products. I did a seven day water fast, but it didn't help at all, since all I lost was water and gained it back immediately. I tried Weight Watchers via mail (since there were no local meetings) and lost about 5 lbs., but gained it back soon thereafter too.
In any case, I'm back in the US permanently now, and don't want to get back into my old patterns of fast food and microwave (unless it's healthy), intermingled with desperate attempts to take a few pounds off only to maintain some slowly increasing status. I went shopping for new clothes yesterday for my new job, and was discouraged because size 16 is now tight, and I am not willing to move into an 18. (I wore a 14 before I went to Estonia). I came home empty-handed.
I want to take off some significant weight, change my WOL, and feel good about myself in a way that is solid and healthy. I think of my return to the US as a fresh start and an opportunity to do it right. Since I've been involved here, I've gotten to feel more positive, particularly when I see how many people seem to have started off at a weight similar to mine, and are achieving their goals. I've gotten a bit of hope here. Even though it's taken me awhile to take off even 5.5 pounds, it is a good thing.
So...that's my history.