How can i lose around 40 pounds?

I'm about 40 pounds overweight, I have very very little will power to do this stuff. =P, My whole family is overweight and we all start to do diets but then gradually get off of it.
I know eat small and stay around 2,000 calories and drink water and...

exersize. Everyone knows that. I just need to do it with someone, none of my friends or overweight so I can't ask them and my mom always does different diets than I do and she won't get up and do anything with me.
So mabye someone on here can do it with me? I just need to know what kinds of food I need to eat. I know yogurt in morning chicken or salad in lunch and somthing small for dinner but only have little snacks. I need someone to do it with so I might get some willpower to go on.
How long will it take to lose 40 pounds healthy and make it stay off? We have a lot of junkfood in the house and I try to not eat it but then everyone else does... so I have to . Please help! Thanks

omg I know how you feel like mon I started my diet and mon night my dad makes rice crispies! yeah I am like in the same situation as u. trying to lose weight without putting on more weight. :]

The standard answer is to have a caloric deficit of 140,000 calories by exercising more and/or eating less.

Anyone who has dieted can tell you calories do not add up like this. As soon as you start dieting your body becomes more efficient trying to hold on to every calorie. If you starve yourself your body will go into starvation mode and conserve all the energy it can.

Your best bet is to try to loose the weight over a long period of time with permanent lifestyle changes. Of all the dieters who loose weight 95% gain it back and often more. This is because after they loose weight they go back to their previous way of life. The way to be the successful 5% is by making permanent lifestyle changes.