You can try to educate kindergarten stuff.
Remember, those people have no PHD in nutrition, so do not expect to much of them.
They are usually much more likely to believe in articles published in newspaper, then to believe in information published in books.
So, the task for you is:
Locate all articles about Sugar
and margarine ever published in major newspapers in your country.
Copy them or print them.
Give them to women/men working in kindergarten.
Do not expect immediate change. It may take up to a year or longer for some people to start accepting the idea that Sugar
Regardless of the time it takes ... you will witness the products of your labor sooner or later.
You can also distribute copies of those articles among other parents.
You can also distribute copies of good educational videos.
People working in kindergarten are more likely to change when under pressure of more then one parent.
Try to talk about it on parent meetings.