English custody requirements are that prisoners are fed three times per day, plus any reasonable request for drink during meals or between meals.
The law (PACE 1984) requires us to provide at least 2 light and one
main meals per day, as well as responding to reasonable requests. That
said, it is normal practice to provide meals when detainees are
hungry, regardless of how much they have had, within reason. As an
example, some homeless detainees may well be far hungrier that those
more fortunate, so we do our best to look after their needs by
providing more food than some others. In short, we do what is right in
compliance with the code of ethics, as opposed to delivering the
'Custody meals. What detainees eat and drink in custody' - Essex Police
8.6 At least two light meals and one main meal should be offered in any 24-hour period. See
Note 8B. Drinks should be provided at meal times and upon reasonable request between
meals. Whenever necessary, advice shall be sought from the appropriate healthcare
professional on medical and dietary matters. As far as practicable, meals
provided shall offer a varied diet and meet any specific dietary needs or religious beliefs the
detainee may have. The detainee may, at the custody officer’s discretion, have meals
supplied by their family or friends at their expense.
POLICE AND CRIMINAL EVIDENCE ACT 1984 (PACE) – CODE C
There is no listed maximum amount of time given between detention and feeding (or between meals) but in practice meals seem to be provided approximately every 6-7 hours in order to meet the legal requirement as well as snacks and drinks for those who express a desire to eat immediately.