I will confess to being relatively new to being serious about losing weight. I don't have any experience with deliberately trying to maintain a new weight...yet. But here is what I have learned. After being around 165# graduating college, I was about 220# when I started cycling again at around age 35. 9 years later, I had slowly ballooned up to 267#. My eating over that time was very much what was described above as "if a little is good, more is better". I was the guy who ate the extra helping at meals, went back for a refill on the large soft drink, and always finished the last donut or cookie in the lunch room at work. Several times in the last year or two, I had decided to lose weight. I upped my weekly exercise total slightly...I "tried to eat healthy"...I "tried to control portion sizes"...and I "tried to cut back on sugary treats". None of that worked, because I have no will power to resist food without some discernible goal to base my resistance on. I would lose a few pounds over the course of a week or two, my focus and resolve would drift, and within no time I would gain it right back.
So what has changed? I started tracking what I ate on myfitnesspal. And suddenly I could see on a daily basis exactly which foods were just killing my diet. Some of the things I thought were "eating healthy" were actually quite calorie dense and I was eating lots of them thinking I was doing something good. On February 22nd, I started aiming for 1500 net calories per day, inclusive of exercise. I have been within 100 calories of that goal almost every day since then (one exception was a travel day). I have lost 16 pounds in about 3 weeks and it has been surprisingly easy to do. I rarely feel like I am starving and I rarely feel like I can't eat something when I want to. What has made the difference to me is having a plan (i.e. stay below 1500 calories), knowing what foods are traps for me that will destroy the day's chance to be at 1500 (i.e. large quantities of milk or dairy products, soft drinks, desserts), and making most of my food at home and bringing it in to work. When we do eat out, my wife and I both spend some time checking out options in the food database on the myfitnesspal app when ordering, and I usually immediately cut the food on the plate in half and ask for a to go box to put the other half in. I know that I am going to snack during the day, so I plan that into my food choices. Instead of planning a big bfast and abig lunch and a small dinner and then starving myself all day in between, I shoot for a 300 calorie bfast, a 400 cal lunch, a 400 calorie dinner, and 400 calories in healthy snacks. We cook lots of food on the weekends, then split it up into tupperware servings to be used as lunches during the week. That makes the planning much easier in the morning since I can just grab something from the fridge knowing it will be around 300-400 cals and throw a few snacks in with it.
What makes me believe that this will be sustainable for me long term is that the knowledge of what foods are gut busters won't go away when I reach my goal weight. I might not count calories every day, but I won't immediately forget how I got where I was. That is the part that is a new lifestyle to me already...along with the cooking foods on the weekend for use during the week. I will let you know how it goes, but even though I am eating 1500 calories a day, I don't really feel like I am dieting right now. I just feel like I am "eating healthy". That is something I plan to make into a lifestyle, long after the calorie counting stops.