Delia wrecks restaurants' profits
"Delia Syndrome" is costing restaurateurs and pub-owners money, as people opt to stay in and cook for their friends.
Fuelled by the increasing popularity of celebrity-chef cookbooks, £39.5b is now spent each year on UK dinner parties.
The survey by insurer Prudential found twice as much socialising occurred at home (55%) than in pubs and restaurants (27%).
Prudential estimates that individuals now spend £1,036 a year on hosting dinner parties.
Delia Smith and Jamie Oliver are far and away the most popular cookbook authors, with 13% and 11% of the total vote respectively.
Nigella Lawson, Gordon Ramsay and Gary Rhodes collected only 3% of the vote each. But the most popular recipes remain those from mum, which were the preferred choice for 22% of people.
Prudential's survey was conducted at the end of January and covered more than 1,000 people aged 16 to 65.
By Chris Druce
Buy this week's Caterer magazine for more industry news and analysis