How should I convince my parents that I want and need to lose weight?

[Jennifer]

I tried convincing my that I want to lose weight, and its more than just wanting a healthy lifestyle, I want to be confident and not feel insecure.My mom says to get braces, contacts, and then the medislim wellness diet(for me to lose weight). She said we can't do all these things all at once and I agree, but I want to lose weight before braces because I feel I will look better. I want to easily find clothes instead of having trouble finding them in a size XL. Since I'm 16 years old, my height is 5'5 and I weigh 170, I have Acanthosis Nigricans(a skin disease from being overweight and dark-skinned) I want to have a healthy and happy life style while I am still a teenager in high school. My mom said she was fat and so was her sister, but now they are thin, and she said she would love to have my full thighs(but they are too big if you ask me), she is always criticizing everybody, including people who are beautiful inside and out, which I think is terrible because I think she thinks that I am not so pretty. One time I asked her what is more important: money or my happiness? She hesitated and said both, I said choose one or the other, she said money is really tight right now and money is how we get by. I understand the situation, but I just want to be the pretty girl that my parents expect me to be, but its too hard because I am committed to taking the time and effort and I need them to reach my weight loss needs(my dad doesn't think I am the most prettiest daughter he's ever had,he's had 5 girls and I feel like the black sheep), One of my friends does this yearly thing wear she takes surprise pictures at the end of the school year, she posted a not-so-pretty picture of me and tagged me on facebook and put "HAHAHA X)" in the comments, I started crying at home, I wanted to tell her how I felt but it's hard to be mad at someone who makes you laugh(she's thin and treats me differently from our other friends). I want to be thought of as decent or cute or pretty or different-in-a-good-way girl, but it's too hard without my parents helping out. My papa likes to eat specific things and I don't think my mom is the type of person who will make a completely separate meal for me and then make food for my papa. I want to be healthy and confident but how can I convince them? Please help

[Mandy]

Since your mom isn't willing to make a separate meal for you, take smaller portions and avoid a lot of snacks. Or try having your mom buy you healthy snacks that way you have a better choice when you are hungry. If your family goes out to eat cut you food in half and take half of it home. A diet isn't about cutting out food groups it's eating them in moderation and it isn't about just your eating habits it's about exercise as well. 60-90 minutes of cardio and core exercise will be the bulk of help for you. If you need help organizing your dieting and exercise foodpyramid.com will help you a great deal!

[luther]

Your parents would know it.