Exactly, fishman. Diets fail because people do them for quick fix to get on the beach. Then they just slowly pile the pounds on because they never adjusted their daily routine to match what they need to eat vs expend.
What I will say is there does come a point where it all slows down when it comes to reducing portion size and watching what you eat. I'm there now and it needs to be about more exercise on a regular basis because I need to work harder. I'm still seeing losses but they are very slow and that's because I'm only a pound or two above the waist size I should be. But I want to lose an inch or two under that yet and that means hitting the cardio more and starting a proper weight training programme (that I keep putting off) as opposed to daily grafting (and the gardening work dries up now anyway).
I agree with Joe too. Losing weight is harder anyway during the colder months when the body moves more into a survival mode wanting more fat.