Stop 'dieting', and start eating right. Whatever 'diet' you choose, you should stick to it for life.
Exercise every day, until the day you die.
I've lost 30 pounds in 7 years, still creeping down.
Whatever shitty habits are corrected by your fad diet will come right back when you start eating fast food again, and you stop your exercise regimen, and you eat high fructose corn syrup-filled sugar bombs.
You want to feel good (and for those obsessed with their egos, look good), forever, don't you?