Chef Raymond Blanc has called on the government to promote organic, British-produced food.
Mr Blanc says bad food does as much damage as smoking
Mass-produced, additive-packed food had "undermined" the family, creating more ignorance of cookery and causing bad behaviour in children.
Mr Blanc told BBC Two's The Daily Politics: "We are facing a nightmare."
He also called for tax to be levied on the airline fuel used to transport food to the UK from abroad, to encourage "a more sustainable form of farming".
Mr Blanc, who owns Le Manoir Aux Quat'Saisons restaurant in Oxfordshire, praised the government for subsidising organic farmers.
'Granny knew best'
But he said 90% of UK food agriculture was "intensive", adding: "More than any other European country, we have completely undermined the role of food and consider it unimportant.
"We need science to tell us what our grandmothers knew thousands of years ago: that food is important to health.
"We are creating a tremendous amount of misery. We have to look at food in a more serious way, a more sustainable way."
Mr Blanc, who is French, said: "We need to reverse our love of fast food and heavily intensive farming, and heavily processed and marketed food."
It could, he added, "create more or less the same damage" as smoking.
In 2001, he likened serving a microwave meal to children to an "act of hate".
He has since criticised UK consumers' love of fizzy drinks and sweets.
In recent years the diet of children in particular has caused concern, with obesity rates increasing and activity levels declining.
Last year, Mr Blanc's fellow chef Jamie Oliver mounted a campaign to improve the quality of school meals in England. Ministers agreed to provide £280m towards this.