What can we do to prevent obesity around the world(especially childhood obesity and diabetes)?

Get kids off their asses from in front of the t.v. and video games and outside playing where they belong.
You know what I find to be one of the loneliest places to be these days?
An outdoor playground.
Why are they empty? Because it's easier for parents to plop their kids in front of the boob tube with a faceful of candy and a limitless supply of sugar drinks.
Educate schmeducate. People darn well know where they're going wrong but are just too lazy to do anything about it.
And how about that wonderful concoction of wires and plastic you're sitting in front of at this very moment? OHHhhh yes, the computer has been a bountiful boon to the state of society's fatness.

I think more and more people are sedentary today. Maybe all people should be required to do a bit of exercising at school or work, like everyone should have to fit in a 30-minute workout before their break or something. This would make it easier for people to get their cardio up, and they will also be able to work more efficiently.
1) Limit access to foods prepared outside the home.
2)Develop good eating habits from an early age. 3)Educate caregivers as to which foods promote health,& start serving them when the child starts eating solid food.
4)Exercise daily.Humans were not designed to sit on their assets all day.
educate the kids about the necessity of havinga healthy diet, avoiding so called junk food, beverages containing too much sugar (I dont wan to mention any names) and regular physical activity (walking, jogging, gym, cycling, swimming exercise)and also relaxation techniques like meditation, yoga etc.
Educate people and restrict access to unhealthy food. As much as I think free will is important, some people are truly addicted to certain fast food companies. While I also think people need to take responsibility, the issue is that innocent kids don't always have parents who are willing to teach them right from wrong. So by removing a source of the problem, it's better for everyone. For example, replace burgers, fries, and pizza pops as school lunches with healthy meals made fresh in the cafeteria.

Encourage tax breaks for healthy food purchases and gym memberships/sports team fees etc. (save those receipts!).

Make gym a *required* part of school again, right up until graduation.

Show kids that playing outside can be just as if not more fun than watching TV or playing on the computer. Make it a family activity day every 2nd day and go for walks, ride bikes, go hiking, etc. It doesn't have to cost a lot. Not everyone needs to enroll their kid in a $500 hockey camp (although that is good if you can afford it!).

The bottom line is this. If we DON'T, our kids (and future kids) will die before their parents. Sad. And preventable.