The NSPCC said every day its helpline assists more than 50 children suffering neglect. It is urging people to act on their instincts if they suspect something is wrong in the light of the cases of Hamzah Khan and Daniel Pelka.
Daniel died of a head injury in March last year after a campaign of abuse by his mother Magdelena Luczak and former soldier and stepfather Mariusz Krezolek, both of whom were jailed for a minimum of 30 years for his murder following a trial this year.
Meanwhile, Hamzah's severely malnourished and skeletal remains were only discovered almost two years after he died in squalor at his mother's filthy, rubbish-filled home. Amanda Hutton was jailed for 15 years for starving him to death earlier this month. Both boys were aged four when they died.
Last year, the NSPCC's 24-hour helpline dealt with reports involving 18,345 children who were being so badly neglected they had to be referred to social services or police for further investigation.
Around one-third of all contacts were about neglect, which the charity said has been the main area of concern for seven years. Many of the children were living in filthy conditions often without enough food or adequate clothing and sleeping on flea-infested beds.
John Cameron, NSPCC head of child protection operations, said: "The deaths of Daniel Pelka and Hamzah Khan were obviously at the most severe end of neglect. But there are thousands of other children who are suffering, many of whom are not old enough to go to school."