Actually I have very little baggage about my childhood, I was very happy but I was picked on because I was fat. I'd have been picked on the same way if I had ginger hair, glasses, braces (had them too), or anything else that stood me apart from other kids because kids can be mean.
I'm actually a bit overweight at the minute because I had a baby five months ago but I'm working on it and I'll lose it in a few months and keep it off. So from that PoV I'm not tied to my childhood, but I also don't want my kids to be!
I can't actually believe that parents don't care if their children are fat. I think people would like to believe that but it's my opinion that parents of fat kids know there is a problem but are not able to admit it openly because they feel judged (and from this thread I can see that this is completely accurate). And yes, perhaps we should judge them, after all parents by and large control what their children eat and if you don't buy crap food they don't eat it. But I think you shouldn't judge unless you are willing to practically help!
As far as solutions, I think there are a few, but I don't have all the answers otherwise I'd be getting paid a lot of money to solve this problem
I think that offering peer to peer help when you have a baby would help, I think it's a community thing. If your kids are on their own and you don't socialise with other mums and see how other people handle problems you rely on other methods (often to do with advertising) to get information. If you don't know any other mums you are less likely to succeed at breastfeeding, and have no-one to turn to when your toddler is being exceptionally difficult and demanding chocolate. Which makes it easier to just give in and let them have what they want.
I also think some basic information on cooking and food should be made available and popularised. How about an 'celebrity family cook' where kids and parents compete together to cook family meals. Perhaps see how Jordan cooks with her kids against oh god I don't know, I don't watch this sort of thing - but you get the idea. If it somehow becomes cool to know how to cook perhaps more people would. I cook and DD is learning to cook, I think that's important. If you understand food and make good tasty food, you eat less than if you eat salt laden crap food.
As far as weighing kids, again I just don't agree with it. Focus on exercise and healthy eating and the weight thing will follow. If you focus on being fat, you will be fat, if you focus on how to live longer and better by being healthier, this too will follow. It's silly to assume that by plonking a kid on a scale and then writing to the parents and saying 'do you know your kid is a bit of a lardarse, how about trying salad' will solve the problem (yes I know you are more indepth than that, but it's mad). If you really believe that some parents just don't care, you won't reach them. If you believe that some parents can be reached then you need short punchy messages. If all the parents take away from the communication is 'you need to do something' make that something as effective as possible. Which means focusing on something active DO exercise rather than DON'T feed them chocolate.
DD is currently walking round the market picking vegetables with DH. Now that is a practical way of her learning about food and also getting some exercise.
Oh and she only has to grow another inch and she'll be matched height and weight so I don't reckon I'm doing too badly!
But this 'I'm such a good parent, I do X and Y, not like these others' attitude is quite conceited and unhelpful. Unless you are actually willing to befriend another mum as a peer and say 'would you like to come to tea with us, don't worry, I'm sure your child will like what we have' etc. it's just hectoring.