user1489670695 I let my kids serve themselves and usually they take as much as they like and eat it. We do not have much waste. But if they do not want to eat something aside from vegetables I never make them clear their plate. It is still waste, it is just waste in their bodies! So a lot worse.
The only reason I don't consider veg in the same category is because my son has a bit of a veg-aversion.
Plating is helpful.
"How would plating reduce waste? Surely the whole point of letting them serve themselves is to let them serve as much as they can eat? If they are confronted with a plate of pre-served food, then it would be understandable if they couldn't eat it all."
Some kids do not know how much they can manage.
So you serve a small plateful and say, there are seconds (on the table or in the kitchen) if/when you would like more.
"the obesity crisis comes more from the cheap availability of processed, high sugar food than been taught to serve yourself and eat accordingly!"
Obesity is a very, very complex issue. Forcing kids to finish off the food they have on their plates is a really unhelpful contribution to it too, IMHO.
user1489670695 "I never heard of "clearing your plate"- which is practice born out of respect for food and the hard work which goes into producing it- as a contributing factor." have you had counselling for issues related to food? Because I have, and a compulsion to clear away food is a factor for some.
User006point5 "No different to throwing it in the bin! Eh, it's totally different from throwing it in the bin, because the calories, vitamins etc are going to nourish a person, and that person will likely eat less for the next meal."
Actually it is worse than throwing it in the bin because the extra food will encourage that person to eat more next time, so as well as eating up more of the world's resources they will potentially become overweight as well.
"... nag them about leaving a single mouthful of food..."
Please OP stop this now, you are going to screw up their natural ability to eat healthily and give them issues around food which could potentially waste a lot more than your mouthfuls. You sound very unaware of food related issues and that could be harmful.