...making a baby/child sleep better/longer at night.
My MIL had been giving me grief about numerous things but one of them is that she is adamant that DS should have a massive meal before bedtime and in order to make him sleep better and that I should make him eat more in the evening. As he isn't a big eater to begin with and particularly doesn't like eating much in the evening, this is impossible. (She also blame my breastfeeding him still as a major contributor)
I'm not interested in anecdotal evidence, there is plenty of that to be had, just whether there has been any proper research into this old wife's tale.