By and large, human beings by their very nature will only do something under 2 circumstances:
1. If their safety or survival depends upon it; and
2. If they believe their actions or omissions will attract a penalty which will be enforced and cause them embarassment.
However, in India, we have added a third item to this list:
3. We take pride in doing what we know is not correct, breaks the rules, is against the norms of civil society etc...
Your problem is not merely confined to wasting food in the canteen. It shows itself everyday on the roads, outside our houses, in movie halls, food courts, malls etc... We blatantly break every rule that we shouldn't. And, when called to account for our behaviour, we either grin stupidly, or, display our 'connections' with the eternal - 'Don't You Know Who I Am?'
Why do I write this? Because the people you refer to are the same as you and me. They are no different. So, what works for you and me will also work for them.
The German story left me absolutely stunned. And, I've lived in Australia for 17 years - a country with probably the highest standard of living globally. Yet, even there I never witnessed that mind-set.
My suggestion is to hit your people where it hurts them the most - their hip pocket.
While its okay to proclaim penalties, fines and the like. But, their problem is that they are 'after the event' solutions and more often than not, result in never ending arguments and some idiot flagrantly displaying his chest accompanied with loud fist thumping. All this in front of some poor attendant who's working for 5 to 6 thousand rupees per month and simply doesn't have the time, inclination, or the appetite to engage the chest pusher and fist thumper. Thats why most penalties are rarely realised.
Instead, introduce a cost per meal with an additional surcharge for wastage. Charge it all up front before the first morsel has even been served. Make it non-negotiable and declare that the surcharge will remain in place until wastage has been completely eradicated. No doubt you'll have a fight on your hands. However, what you will also have is people who are paying for their meals. And, we all know that we don't like wasting what we pay for - at least in the majority of instances.
22nd June 2011 From India, Gurgaon