IMHO: no one ever needs a diet plan. Diets don't work. Weight watchers, Jenny Craig, Slimfast---all are just temporary ways to lose weight.
All you need is to count calories and exercise. Those two things will ensure that you lose weight.
I count every calorie that enters my mouth and I log it into fitday.com. I eat between 1100-1300 calories a day (usually). By knowing what you are eating you can monitor how many calories you eat. It's all math really. Count the numbers and only eat that amount.
I also exercise (I should be doing that right now, but I will!) almost every day. I usually give myself 5-7 free days in a month. But anyway, I do wii fit plus, it's a video game that is Fun! and doesn't feel like torturous exercise. I also like to do zumba! I sweat like crazy and feel so invigorated.
ANYWAY! That's the magic formula for losing weight. Count your calories and exercise.
You can do this!!!