Actually I was taught in my university nutrition classes that children up to the age of eight are far better at regulating their food intake than adults. If you actually let a child eat anything they want they will end up eating a pretty varied diet and they are far better at portion control than adults.
Helen. New Zealand living, cloth nappy using and making. Totally addicted to knitting. Mum of Samuel (11/05), Mollie (6/08), Meghan (5/10) and Benjamin (17/1/2013) born 19 weeks 2 days.