I'm actually doing a market research study right now about obesity/weight gain/loss journeys. I'm speaking with 50 people of all different weight levels.
I feel that the right recipe for weight loss has to be diet in tandem with increased physical activity, especially for people past a certain age. The people who have been able to lose and maintain weight typically, from what I've seen so far, are those who aren't super-super restrictive. They have basically healthy eating habits, but don't follow any particular program or diet. If they have a craving they might give in a little (if they want chocolate, eating a little bit) and they don't beat themselves up for occasional guilty pleasures.
They want to enjoy life, and they do enjoy life. As a result, they don't have an austerity mindset. They learn to enjoy healthier foods, and they learn to enjoy exercise, which the successful ones do regularly. I've spoken to runners and walkers and even a female body-builder.
It's been a really interesting project.
My most personal successful weight loss came when I avoided simple carbohydrates. I did not feel deprived at all. I have just signed up for a self-mastery program, of which "energy" is a module, and that covers things like eating and exercising. I'll let you know how it goes, but in general, I'm looking to stay relatively strong and flexible for my age, and to lose about 10 lbs.