Consider this map. What is shows is the growth of an epidemic over a four year period. Can you guess what the statistic is that it's tracking?
An epidemiologist might be seriously concerned with these growth numbers. A virologist would probably question what the CDC is doing to stop the growth of such a rampant disease and health care workers everywhere might be in a panic over treatability and isolation.
Over the last week, a few articles have hit the news wires that have left me in a seething, ranting fit, culminating today in a discussion sparked by an "article" on FoxNews (of course).
So, first of all, the school district shouldn't be allowed to classify a child as obese until they can prove that it's not their deadly food and lack of physical education that are the main contributors.
In it's current accept usage, BMI is improperly referenced as a measure of obesity rather than an observational starting point for individual data collection and analysis. To suggest that BMI is the MEASURE by which a child is called "fat" is scientifically improper as it describes a scale along a statistical norm and NOT the basis of individual measure. The only way I would accept BMI as a data point is if it was corroborated with correlating individual data, eg. Body Fat % and Lean Body Mass. "Because Shelby's BMI was observed to be on the high side of normal for her age group, we tested her body composition (caliper method) and determined that she was 23% body fat, which is high for a child her age[...]"
Personally, I would argue to tell the school nurse (who should know this already) that BMI is irrelevant and useless without corroborating, individually unique data. The only body composition numbers that are important for measuring health and fitness for an INDIVIDUAL are Body Fat Percentage and Lean Muscle Mass.
While everyone SHOULD be upset with this gross misconduct, the story is pomp and bluster, and I believe that they are 'angry' for the wrong reasons. While the patterns for healthy eating habits and fitness start at home, our children spend 80% of their time at school, and the environment is toxic and sedentary. IF FoxNews and the parents were REALLY upset there would be a LARGE outcry against the irrelevance of the measurement and the environment that put them all in this situation, instead of politically charged BS about 'who's invading/violating whose rights.'
I would say that a healthy country (in just about any sense of the word) starts with a healthy family. Our schools should not be the enforcers regarding our kids health, but they should definitely be the primary benefactor. Childhood obesity has more than tripled in the past 30 years. The prevalence of obesity among children aged 6 to 11 years increased from 6.5% in 1980 to 19.6% in 2008. The prevalence of obesity among adolescents aged 12 to 19 years increased from 5.0% to 18.1%. 
What's the financial impact on our Health Care Industry when there is a pediatric load on the system with adult issues (High blood sugar, type II diabetes, high cholesterol, and all the other hyperinsulinemia induced diseases)? When the cost of a patient over a lifetime can almost TRIPLE because of the childhood onset of obesity related diseases (which doesn't even CONSIDER the rise of 'elective' treatments related to obesity on the rise with teens) , I think this is actually one of the easiest to solve issues taxing the entire system, and America is to much a coward to fix it.
Americans dig their own graves with their teeth.
Consider it's national security impact. ABC news carried a story about an opinion from Mission: Readiness (a think tank of retired military officers)called “Too Fat To Fight” (check out the Counter Think Comic) detailing a new report that says that more than 9 million young adults, or 27 percent of all Americans ages 17 to 24, are too overweight to join the military. Now, the officers are advocating for passage of a wide-ranging nutrition bill that aims to make the nation's school lunches healthier.
All this to say that while I don't think a school should be testing kids for obesity without being a MAJOR contributor to the solution, I also think we all need to take responsibility for the health and wellness of our children, lead by example and stop killing our kids with bad information, poisonous food and no motivation.