We always used to share with our DC from our plates when eating out, until they were around 5 or 6, and it's now the norm that all children, however young, choose their own starter, main and pudding as standard. The portions are invariably way too big, for the adults as well as the children, so there is either loads of overeating or loads of waste. I don't personally think it's a good thing to have the next generation thinking that either one of these doesn't matter.
Estranged Son and Future Granddaughter
To think that London, or anywhere else for that matter, does not belong to any one demographic