Tightening budgets will encourage more and more people to rely on cheap fast food, often high in fat and salt, he said. The other, more sensible, option of self-cooking is just not available for them - for they simply have lost the skills to make healthy meals on a budget, James Oliver told the Commons Health Select Committee. It would perhaps be a "new kind of poverty," he felt.
The chef, famous for a crusade to improve the quality of school dinners, has just produced a documentary Jamie's Ministry of Food, which calls upon people to "pass on" a couple of simple recipes to each other to improve the nation's health.
Rising obesity rates are a "bloody emergency," which Britain has just 10 years to tackle, Oliver said.
One in four Britons is now classed as overweight or obese, while the predicted recession could make the situation worse, the chef warned.
"If we don't deal with it in the next 10 years, it's going to be 10 times harder to fix, and it will be a horror show," he said.
"This is the first time in British history that we have a large number of people who cannot cook," he told the committee.
"If you have knowledge about how to cook you will know how to buy efficiently and cheap."
He called for the Government to step in to teach cooking to help working mothers, as payback for the tax that they contribute to the economy.
Increasing numbers of women going out to work in recent years had left whole generations without basic cooking skills, he said.
He wanted the Government to teach more people to cook and for councils to cap the number of fast food restaurants in certain areas, using local planning laws.
Despite Government pledges on healthy school meals, hardly 5,000 of the country's 125,000 dinner ladies had received training over the past five years, which was a "bloody disgrace."
While he praised the Government's investment in school meals. he also said that £650 million spread over six years amounted to just "pennies" for each child.
Ministers would have to spend "ten times" as much to deal with the problem, he said.
A spokesman for the Department of Health said that the chef was doing "great work" which complemented Government initiatives.
He added that the Government had recently announced that every primary school child would be given cooking lessons.
The School Food Trust said that many local authorities and private companies organised local training for their staff as well as national initiatives.