I lost about 45 pounds in the process of about 4 months, and over the last month and a half, put back on about 15 pounds. That's why diets that are too restrictive are bound to fail. You need to have strict rules but not a strict diet per se. You can say "I absolutely, without fail, will work out for 20 min every X, Y, and Z day of the week". Or "I will only drink diet soda and only liquor with diet soda", "I will never add sugar to anything - only low-cal sweetener", "I will only put the lowest-calorie dressing on my salad", etc. When a diet is too tough, you begin to cheat a few times, and then the momentum builds and you're fat again before you know it.