Portion control is key Tnthomas I agree, I still don't measure anything but don't eat the humungous servings I did when I was younger. Now that I'm a senior, I can't be that careless, the pounds pack on too quickly. I'm not pre-diabetic yet, but I always have that in the back of my mind. Nobody in my family was/is obese, but my father developed diabetes in his old age that he was able to just control with dietetic foods, but my sister is on daily medication for her diabetes and my mother was taking insulin injections and ended up dying from a diabetic stroke which led to coma.
Mathjak, eat less and move more works well too, no doubt. I notice if I'm out camping and taking long hikes every day and getting in extra activity, I'll always come home with a loss of around 5 pounds in a few weeks without even trying. We eat well on those trips, not denied anything really, actually extra treats, etc.
When I was going to the gym and doing exercise classes like Zumba, I was able to shed ten pounds over time. I'm usually just ten pounds over where I'd like to be, lose it and gain it back again...but I try not to exceed that.