This follows the publication of the first part of a wide-ranging survey designed to shape the future for PSB on the terrestrial channels.
A survey of 6,000 households revealed that viewers are less concerned with arts and religion coverage than they are with children's programming and news.
This will be welcomed by the broadcasters, who have lobbied to have their statutory commitments to the religion genre in particular reduced.
"We have to show 404 hours of religious programming a year and it's not highly demanded by our customers," Graham Duff, the managing director of ITV Sales, said.
In its report, Ofcom said ITV and five should concentrate their PSB requirements on news, regional news and original production.
In the light of viewers' concerns about originality and innovation in TV, Ofcom reiterated its support for the current remit of Channel 4, which is meant to champion new formats.
There was also a warning for the BBC, which is gearing up for its charter review, that it "needs to reaffirm its position as the standard-setter for delivering the highest quality public service broadcasting".