The chancellor's comments came on the day England reopened its beloved pubs and the rest of the hospitality sector after more than three months of lockdown.
Sunak said the nation had to "relearn what it's like to go out again", adding that the closures had been especially painful because consumption made up about two-third of its GDP.
"That's more than most of our peers," he told The Times.
"So we've got a situation like this, with social distancing we're obviously going to be particularly impacted by that."
Sunak said he was "worried about a generation that is scarred by coronavirus", taking note of how unemployment hit the youth the hardest.
He added that there was no reason to "lose that generation... if we can get these next few bits right".
"This is a consumption-driven economy; people used to, three months ago, go out with their friends or family to go and have a meal. Or buy a car, or upgrade their house, or move house. Go camping, come up to the Yorkshire Dales and go coast to coast," said Sunak.
"Eat out to help out."
Sunak believed the idea was "really about social justice".
"People act responsibly, but ultimately if we eat out to help out we can protect those jobs. It's not abstract."
The true scale of Britain's unemployment problem will only be revealed once the government starts winding down its jobs furlough scheme in August.
The state currently supports 80 per cent of most people's wages. But jobless claims still surged 126 per cent to 2.8 million in the three months to May.
Sunak will make an economic statement to parliament next week that will be watched closely for signs of how much support the government intends to give businesses in the future.
The government is running up debts but interests rates are low and borrowing costs remain at a historic low.
The Bank of England's chief economist Andy Haldane created waves this week by predicting a "V-shaped" recovery that will see old levels of performance return soon.
Sunak was less certain. "We all want Andy to be right," he said.
"The things we’ve done over the past few months put us in as strong a position as possible to have as strong a recovery as possible. But we have got to be realistic as well. You can’t shut down your economy in the way that we have for this many months without there being hardship as a result."
