Jeremy Corbyn has insisted porridge and energy bars are helping to fuel his bid to become prime minister.
The Labour leader said the Conservatives could still decide to call another early election but he is ready to keep campaigning for the long-term.
Theresa May's minority Government, propped up by the 10 DUP MPs, would rule until 2022 under the five-year gaps between parliamentary elections outlined in the Fixed-term Parliaments Act.
But the option to trigger an early election exists under the 2011 legislation, with Mrs May facing another turbulent year politically as the Brexit negotiations intensify.
Asked if he could sustain the momentum for another four years, Mr Corbyn told the i newspaper and the Independent: "We've got lots of energy. I've got loads of energy, I'm fine.
"I eat porridge every morning - porridge and energy bars - and I keep off alcohol and meat."
On the potential for an early election, he also said: "The scenarios are that the Conservatives implode to some degree or their position becomes untenable and they decide to call another election and we'll take the battle out there."
Mr Corbyn added he wants to involve local parties in developing policies tailored to their regions.
He said: "For example, the party in Cornwall is looking at how our policies on investments would affect Cornwall, what the industrial opportunities needs are, what the social needs are, what the housing needs are."