Question: When people are unable to finish shared food, they tend to pass the dishes around to clear them. If I am the last one but cannot finish it, would I be at fault for wasting food?
Answer: It would be everyone’s collective fault since the food was shared. If the food is not compassionate and wise, the guilt needed should be due to the fact that animals died or suffered in vain. There is however no need to deepen negative affinity with these animals by eating every morsel of them. There should be resolution to order less dead animals and their products in future, best not to do so at all. If the food is alright, there should be these actions accordingly.
 If home, with little or much leftovers, why not refrigerate them for later?
 If elsewhere, with much leftovers, why not pack a takeaway for later?
 If elsewhere, with little leftovers, why not urge all to have another round to clear it all?
What The Buddha Taught About Eating And Drinking
Why Do Buddhists Avoid Meat-Eating & Practise Animal Liberation?