I've been fortunate over my lifetime not to have much of a problem with weight, but I've still had pounds creep on from time to time.
For me, the solution has always been to eat fewer calories than I expend, i.e., eat less, move more, and avoid empty calories (i.e., fat and sugar) like the plague. It doesn't take violent exercise, just moving more, walking more, etc., and being aware of the calories I take in -- not OCD about it, just generally aware that an apple for a snack is better than ice cream, etc. I have a serious weakness for sweets, so I do not keep them in my house. I very, very seldom use pre-prepared foods because when I look at the labels I'm horrified at how many more calories, fat and sugar are in them than what I can prepare from scratch.
I have osteoarthritis, which strongly motivates me to keep the weight off, because extra pounds to carry around increase my joint pain, especially in my knees. Since I was a child my digestive system has always reacted violently and very unpleasantly to too much fat, so this has always made it easy for me to avoid fried or fatty foods and I guess that's one of those blessings in disguise.
