Just like abstinence, diet and exercise works every time it is tried. But for the truly obese (not just overweight) exercise can be strenuous on your heart and joints. That's why I recommend exercising in the swimming pool as a first step. You don't have to swim. Just walk along the bottom. Just keep moving. The water will support the weight so you can build up endurance and begin slimming down.
I agree. After losing about 25% of my weight, I can say it takes quite a bit of effort and will power. At least it did for me anyway. When I started, I was overweight and out of shape. I basically had to get in shape, before I started to losing any weight. It took me 6 months or so to lose the first 10 lbs through diet change and walking 90 minutes a day. I hit the wall by just walking. As soon as I added pushups and situps, the weight started to fall off.
I can see how people say to heck with it after a couple of months of no perceived results.