Food and drink manufacturers have attacked Ofcom proposals to ban junk food adverts targeted at under-16s.
An ongoing debate over childhood obesity sparked Ofcom's decision
The Food and Drink Federation (FDF) said it was "shocked" by the decision, adding it feared that the planned regulations were "over the top".
Ofcom said the moves would cost broadcasters an estimated £39m in lost advertising revenue.
The proposed changes are expected to be enforced from the end of January 2007, and be phased in over 24 months.
Channels dedicated to children's programmes are expected to be the biggest losers.
Ofcom estimates such channels could lose as much as 15% of their revenues while cable and satellite channels targeting children and young people could lose up to 8.8%.
The cost to commercial public service broadcasters - ITV, Channel 4, Channel 5 and GMTV - would be around 0.7% of their revenues.
The news could prove to be a further blow for ITV which has been suffering from a decline in advertising revenues which still makes around 90% of its advertising revenues from ITV1.
The growing public debate about childhood obesity has prompted Ofcom to make the move.
Its decision to target youngsters below that age of 16 comes after two years of research and consultation.
Originally, it had been widely expected to settle for a ban on adverts aimed at under-fives, but fall short of affecting TV advertising before 9pm.
However, the new rules mean any adverts for foods deemed as too high in fat, sugar and salt cannot be shown during pre-watershed adult shows that are popular with children.
"We are shocked that after a lengthy consultation Ofcom has moved the goalposts," FDF director general Melanie Leech said.
She also argued that the guidelines for which foods should be targeted by the ban were "scientifically flawed".
"The debate around this important issue has been based on high emotions and subjective opinions rather than a sensible dialogue about how we can tackle childhood obesity," Ms Leech said.
The Advertising Association gave a "mixed response", saying that said while it welcomed Ofcom's decision not to adopt a pre-watershed blanket ban, it was unhappy at the decision to widen the ban away from primary school children.
It added the "draconian measure" could mean a difficult future for UK-produced children's programmes as reduced advertising revenues would mean less money to plough back into shows.
Flextetch, which provides content for cable broadcaster NTL, including the youth channel Trouble, said Ofcom had gone "substantially further" than expected.
"Advertising revenue is essential for companies such as Flextech to invest in quality programming for the benefit of all audiences, including young people," a spokesperson said.
Fast-food chain McDonald's welcomed the recommendations, saying they had helped bring some clarity to the debate.
Some food companies had already taken pre-emptive action ahead of the ban.
Just days ago, fast food chain Burger King said it would voluntarily stop making and showing television adverts in the UK aimed at children from 22 December.