Yes! It happens although it shouldn't..
"Are we contributing to wastage?" - food in particular. How often do we order more than what we will eat? At most of the time, this is what I heard, "...I know I can't finish that but it doesn't matter. I'm paying for that portion, so just let them serve what I deserve with the amount of money I pay..."
'D.e.s.e.r.v.e'
Just because we deserved the portion for the amount we pay, we are causing food wastage... although we never did have the intention to finish up the food. Be it expensive or cheap, it is still an act of wastage.
Maybe we will not be offered a cheaper price for a smaller portion.. but if you don't feel good for paying the same amount for lesser food.. ask for 'wrap-up' / 'ta-pao' then. And here, I would like to remind you, do bring along a tupperware - just in case. When we are trying to reduce food wastage, we are trying to do our part to protect our mother earth. Reduce plastic usage!
Back to food. Maybe some will say that they will not even eat the food even if they bring back the remainder food. So.. instead of wasting, why not ask for a smaller portion? Whether we will be given a discount for the smaller portion or not, at least... we are not contributing to wastage.
The first step will always be the hardest part. But once done... it can never be easier. It's as simple as that. But still... it has to come from within our heart. For the thought + action + sincerity that make the difference.