Mom, can you please loose some weight?

My son, I love him more than life. Since he has entered the first grade, he has started to notice different body types. Short, tall, fat, skinny, kinda fat, black, white, brown, etc. Upon noticing these body types, he has very matter-of-factly let me know that I am fat. He is never rude about it and doesn't mean any offense, he has merely stated the obvious.
He just completed the 5th grade and has been asking me for the last 5 years to loose some weight, that he wants a skinny mom. I have found it endearing and thoughtful. I think part of it is he has also noticed that skinny is more socially acceptable and he just wants his mom to "fit in" more. He doesn't realized that I am just not a social butterfly and I prefer not to be in huge crowds and big parties. I like small groups of friends to really get to know a few special people.
We have discussed why he is asking me to loose weight and he just says that I should be skinnier. I think he is reluctant to tell me if he does know or maybe he doesn't really know why. But he continues to ask me in earnest concern for me. (and maybe him too, who knows....)
Today I took him to his dad. His dad lives 4 hours away and we meet in the middle. Halfway there, he starts talking about my weight again.
"Mom, can you please loose some weight?" He doesn't know that I am about 100lbs overweight. Ok, clinical obese. (Yucky sounding!)
He doesn't know, either, that loosing weight has been on my mind in a more serious way for almost a month or that I have already been working towards changing my thinking an attitude towards food. Fast food is starting to taste blah to me. We stopped at Micky Dee's for a quick lunch on the way there today and the hamburger meal tasted to bland. I didn't even finish it. Maybe it's the summer, but I have been craving salads and free fruits/veggies lately.
"Mom," he continues, "You can loose just 20lbs. Can you do that this summer? While we are gone, can you loose just 20lbs?"
OMGosh! I think my heart is melting right out of my chest. I think I have the best 10 yr old son in the whole world! I am driving and thinking.....he is compromising with me, not to loose everything over night, but just some. To just make an effort. He made a bargain I could not refuse....I told him that I would do my best. I meant every word.
I have a goal.....to loose 3-4lbs each week. For my son....for my family.....most importantly, for me.
I will be posting each day as much as I can remember to help myself stay on track. I don't know who is out there reading, but any encourage will be appreciated!