Two things:

I am old. When I was young they had very few fat people. We also had very little sugar, and coca-cola was served in six ounce bottles. Six ounce. What changed? Sugar wasn't even allowed to be grown in Florida before WW2. And then the food pyramid...financed by the corn farmers and food processor, etc...

Also, I lost a LOT of weight. It was difficult. But even more difficult was adjusting to the weight loss. Mentally. I think that's why so many people rebound. (That Oprah lady for one.) I have been blessed.