They could set one simple achievable goal which would drastically reduce obesity: every single high schooler graduates as an athletic machine. The government could do it easily. Schools already require students to participate in gym class, the problem is that it's an absolute joke. They could change that if they wanted. The health benefits are obvious. It's not like they don't know it's an option. They just make excuses for why they can't make any progress fighting obesity, probably because they don't want a healthy population.

Of course some in shape people will become fat as adults, but almost all fat adolescents stay fat until they die.