Defeated...What to do about fat kids?

Saturday I took my son to a make up kung fu class. He did very well, but I lost. Nothing to do with kung fu. We arrived in time to watch the tail end of the girl's class which made my heart break and my blood boil and I couldn't figure out a single action to take. All the girls in the class are under the age of 12. Three of them were really fat. Get it straight. These were not kids having a chubby phase before they stretch out or kids just going through a little pudginess, or even kids just a little on the heavy side. These girls were really fat. My guess is TWICE the amount they should weigh. Anther small handful were probably technically overweight as well. It was the belt test for the girls, so one of the very heavy girls was having to respond to a stranger "attack" from the kindly, supportive, twinkly eyed kung fu teacher. In under 5 min, in a space of 12' x12', she was wheezing, red faced, panicking and crying. I heard someone ask her Mom if she had asthma. Her Mom said she did not, she was just nervous. This situation brought up SO MANY conflicting feelings for me. On the one hand, how wonderful that these parents are paying for an expensive martial arts program to help their daughters be more physically assertive and accomplished. On the other hand...get real! Once a week of a little kung fu is not going to change an 11 yr old who weighs twice what she should. The line between being a parent and caring for your child's health and creating poor self-esteem is, I agree, a fine one. But, I'm sorry, allowing your child to be 75lbs overweight at age 11 and basically NON FUNCTIONAL is just wrong. This little girl could never run across the playground when the bell rang. She could never run and play with a group of kids. I can guarantee her parents would find it unacceptable to prevent their daughter from learning to read or write, but somehow it has become ok to raise your child so that they cannot function physically. Being a parent is really hard and there are a million things to do well. I hate to find myself criticizing people's parenting. But there I was, truly angry at the physical condition of these kids. I watched the little brother of this girl eat an entire box of Wheat Thins during Kung Fu class!!! Wheat Thins contain soybean oil, flour and 3 types of sugar along with some other crap. If you are reading this and you don't know me well, please be assured my kids eat far from perfectly. For one thing, 50% of their time they live in a household where white bread, noodles and dessert are the staple foods. Just so you know I get much more worried when I see a kid who is all bones and titchy and weedy, than I do when I see a slightly heavy kid. My vision of the perfect human body runs more along the lines of farmer than triathlete. I am not in the business of being a parenting food zealot. BUT THESE KIDS ARE HUGELY FAT AND NON FUNCTIONAL. OK-so, in my mind, while this girl was gasping and wheezing and crying, I thought of all the ways I could make a difference: I could offer the owners of the kung fu studio a free nutrition talk for parents of their students. I could walk straight up to the Mom and say "Hey, I work with people to increase their fitness and health. I think I could make a difference for your daughter. Come and see me. No charge." I guess I just completely chickened out with the second option. How do you offer that kind of help and support without someone potentially feeling extremely insulted and offended? She didn't ask me for help and basically, it isn't any business of mine how her family cares for itself. As for offering to do some free nutrition work through the kung fu studio, I changed my mind about that when I saw the class assistant for my son's class... a huge young man. This young man was extremely kind and wonderful with the students and I'm sure he could keep me safe in a dark alley, but as a wellness role model? I was just stumped. I felt very disempowered. On the one hand people's lives are private and their health is their own business and I believe that strongly. However, that also feels like turning my back on a situation right here, in my own city, in my kids' own kung fu studio. I will be spending the next few days thinking about this and trying to either think of an appropriate response or make peace with doing nothing. Let's end with some Paleo kid snacks: carrot sticks with salt, celery sticks with a little nutbutter mixed with raw honey, nuts, grapes, apple slices, sunflower seeds, cubes of meat, pre-cooked turkey bacon, plantain chips, coconut/gelatin "jello" squares, home made trail mix, pieces of Lara Bar.