I lost 40 pounds in 3 months, then another 20 in 3 months.

I've kept the weight off for another year.

I still eat healthy and in moderation (and occasionally fast).

I avoid sugars and high-carb foods and my body has been hovering at the same weight.

Maybe, for some people, it's harder to keep the weight off (assuming diet is the same)? Or, maybe some people don't have the mental will-power to stay on the diet that lost them the weight?