Losing weight & keeping it off

Hello everybody, I'm using the app with the hope it will get me to my goal of keeping off 35 lb. Been yo yoing over the past few years and have only been able to keep off a few lb of my original weight loss. I've recently come to realize that I have to count and keep track of my food for the rest of my life. Can't be too hard? I see people around me every day on what must be calorie restricted diets and they seem to be doing fine. Wonder though, is the waistline or body type of my youth (I'm in my 50's) attainable now that I don't smoke or drink coffee any more?