Britain is witnessing a "new poverty that we have never seen before," Oliver told parliament's health committee.
"This isn't about flash trainers or mobile phones or Sky dishes or plasma TV screens. It is a poverty of being able to nourish their family, in any class (of society)," he said.
Oliver, who is on a crusade to improve Britain's eating habits, said that in previous downturns households were more equipped to trim costs and still make food "nice and tasty."
"But this is the first time in British history where you haven't got most of the population able to cook and you can statistically see where people are spending their money now and fast food options are up," he said.
Oliver added that the problem straddled all social classes.
"It is genuinely classless. There's plenty of city boys, who used to earn a load of money, that can't nourish their kids properly even with a gold (credit card)," he said.
The chef, who almost single-handedly convinced the government to spend an extra 200 million pounds on improving dinners in Britain's schools, warned that Britain was facing an "incredibly profound" health crisis. At a news conference after the hearing, Oliver said obesity was now an "epidemic."
If we leave it, it will be like America
Last month, Oliver set out an anti-obesity "manifesto," in which he called for more cookery education and government-funded food centres in every town.
It calls for cooking skills to be taught in primary schools as well as to adults at work and in the community.
He demanded the government appoint a dedicated minister for food from within the private sector to drive policy over the next decade.
"We are not in a great place, but we are in a place from which it can be fixed," he told the committee.
Despite his healthy eating campaign, Oliver stressed he was not against fast food.
"I don't want to demonise fast food. Burgers taste good, pizzas taste good, kebabs taste good (but) what we've got is a large group of people (only) buying into those options," he said.
Jamie for Minister of Health... or is he becoming a bit too preachy?