I second the thought that we choose individually what we put into our mouth, and how much of it we consume. Even with healthy food, like rice and lentils, eating too much will eventually make you overweight.
The hectic lifestyle we lead makes it appealing to eat fast food or to "eat out of a box". How healthy is it to consume a lot of preservatives which are added to your prepared or frozen meal so that it can have a longer shelf life? But it seems so much easier to open a can of vegetables than cut them up. However, the detriment is the ingesting of all the additional salt and preservatives put into the canned food. This is a personal choice that we have to make as well.
I've heard of (and applaud) the schools that are taking out vending machines full of soda. It is a bold move.
The other point to consider is how much exercise people get. I know several people who get winded just walking up a flight of stairs--yet they are in their 30s! It's important to have a balance of a healthy diet and exercise. It is not necessary to exercise for hours a day like I was taught as a child; 15-30 minutes of exercise a day does wonders.
As for the government, well, I currently live in England and they are considering putting flouride in the water because the children's teeth are so bad. There is a lot of research *against* putting flouride in water...but it is so much easier to do that than point the finger at the parents who are either not educating their children about food choice or making sure their children take care of their teeth or whatever other reason I am not listing here.
Governments are doing some education about healthy eating. But is it enough to counter the clever marketing of the fast food and candy companies? I don't think so.