I think Monty, Knottie and iDave make some good points.
My point of view has always been to control my weight by chosing what to eat. Its ok to exercise like mad when you're young, but when you're older, the weight will go back on, unless you have learnt what works for you. You need to find a dietary solution for life.
I exercise for other reasons, not to control weight, but to keep all the important stuff in good working order, heart, lungs, etc and to slow the reduction of muscle tissue.
As MLB writes, I do believe that you need to get on board the calorie thing. I believe its quite simple, and I refer to you to a recent article in the mag discussing "energy balance". Those who consume too many calories could be regarded as being in "positive energy balance", according to the magazine article, hence the accumilation of excess calories as stored body fat.
Therefore the obvious answer is to run a calorie deficit, as MontyLikesBeer points out. Then the body will get the additional calories it requires from your fat reserves.
As you know, theres a lot of opinion about what we should eat, I believe that you shouldn't cut out any particular nutrient, but should manage them all.
Again I refer you to another article in the Mag where Pasta was discussed.
I had always eaten pasta, but had forgotten about it in recent years. The article got me thinking, and I started eating it regularly again. Its certainly helped with that drousiness I use to feel between 12:00 and 3:00pm.
40g of dried pasta (not egg based pasta), with perhaps a small tin of tuna in spring water and a simple, light, vinegarette type dressing, for lunch, has sorted me out for post lunch lack of energy. Pasta is low in fat, and has very good contents of carbohydrates and protein. Obvously I don't eat that everyday, but very the theme.
At this point I was going to list what I avoid and restrict in my own daily intake, but instead I very much endorse what Knottie8 recommends, which is to take the time, while shopping at the supermarket, to read the label, the nutritional content table.
Its an eye opener for sure.
Also, very important, do not cut-out carbs and do not cut-out protein. Doing so will see your body getting these from your muscle tissue. The body will "harvest" protein from your muscles, if you don't give it any through your diet, and it will also acquire its carbs from the braking down of bodily protein.
I have a weekly eating routine, I know what I'm going to eat and why I'm eating it. I no longer get hungry between meals, although when the bordem sets in, its still tempting to drift towards the fridge...
I do occassionally stray as mentioned earlier, perhaps once a month I'll have Fish-n-Chips. But its because I rarely have such food, that when I do, it is such a treat and I enjoy it all the more for that. IT could be Fish-n-Chips, could be a Ruby, whatever. I believe its impotant not to cut these things out entirely, but instead reserve them for rare occassions.
Watch your calories, exercise, do not cut-out any particular nutrient such as protein or carbohydrate, regain control of portion sizes and most importantly, imo, exercise your self discipline. Without that, nothing is going to change.