I, too, am a yo-yo dieter. I *KNOW* how to lose weight... I've done it at least 6 times in the past. I haven't figured out how to "keep" it off yet. But that's not REALLY true. When I face myself in the mirror & ask myself the really HARD question "WHY CAN'T I KEEP THE WEIGHT OFF?" ... you know, I finally had the audacity to actually answer! I can't keep the weight off because I keep going back to old habits. Junk food, 2nd portions, lack of giving a damn...

But it always comes back to ONE specific thing: NOT EXERCISING.
Now, don't get me wrong, I LOVE to exercise! - I love to swim, bike, walk, lift weights, etc. But the past few years, I've stopped exercising for one reason or another (most often, an injury or illness) and once I stop exercising, I stop eating healthy & start eating crap. I'm not sure WHY I do this. Mentally I know that if I just stay on track with healthy eating, I probably won't gain weight (or
as much weight, anyway) & yet, I throw caution to the wind. The LAST time I lost weight (I had dieted/exercised down to 138 - just three pounds from my goal weight!) I re-injured my shoulder (had surgery back in 2002) and had to stop lifting weights... couldn't even WALK because the natural *swinging of the arms* HURT my shoulder.

But instead of sticking to my healthy eating plan, I started eating pizza... 2 slices, 4 slices, a whole pizza... chips, cookies, etc. Just CRAP. ACK! - and I wondered why I gained the weight back, plus some! HA! What a dopey goofy stage of DENIAL I was in.
Then I developed blood clots in my lungs & the meds I was on left me absolutely DEAD TIRED. I could barely drag my self to work & when I got home, I'd eat dinner & go to bed around 7:30!!! .... that piled on ANOTHER 20+ pounds.
Well, I'm "healthy" now. I had elbow surgery last month, & that's not healed enough to lift weights again, but I can walk, bike, & I swam an hour a day all summer. I started eating healthy again. Cut out the junk food. No more sodas, etc. Watching those portion sizes! - no more 2nd helpings! - for THREE SOLID MONTHS, I was a dieting angel.
BUT I DIDN'T LOSE A SINGLE OUNCE.
I'm 45 years old, in perimenopause, and finally discovering what my mom was talking about when she said "your body will be different in your 40's than it is in your 20's young lady!"
Bottom line here... I've finally come to face my diet demons. *I* need to exercise. Some people can lose weight & keep it off w/diet alone - I CANNOT. And if I get sidelined from exercise for ANY reason, I need to really watch my intake... stay AWAY from junk food, & MEASURE OUT portions.
I keep gaining weight for a reason. That reason is me. I think that is the absolute secret to weight loss & keeping the weight off for good.