I'm 59 and have lost 30 lbs over the past few years. Actually, I lost the weight two years ago and have kept it off. Before then, I had steadily gained weight for years even though I was exercising a lot. What worked for me was starting to track my weight and calories every day. I started when I got an iPhone about 3 years ago, and downloaded a tracking app (LoseIt!). With the program, you enter in all of vital stats (age, weight, etc.), your goal weight, and how quickly you want to lose weight. I chose a goal of losing 20 lbs at a rate of 1 lb/week, and I lost weight at that rate almost precisely. I worked so well that I reset my weight-loss goal to 25 lbs and then 30 lbs.
When you start tracking your calories, you quickly realize how much you are actually eating. You have to be honest, however, for it to work. You have to track every single bit of food or drink that you consume, and measure quantities carefully. You also get credit for how many calories you burn through exercise, and you have to be honest about that as well.
Along with tracking, you also have to start changing the way you eat. Cut back on portion sizes and second helpings. Reduce the amount of beer and alcohol you drink. Eat healthier foods with more fiber.