Speaking to Conservative MPs Esther McVey and Philip Davies, Mr Johnson was probed on plunging Britain into lockdowns during the Covid pandemic.
In a GB News Exclusive the PM said the Government had to get the balance right while prioritising public health and saving lives.
Despite admitting lockdowns had badly affected the country’s physical and mental health, Mr Johnson could not rule out implementing more should Britain be hit by another pandemic.
When asked about a future lockdown, he told us: “I can’t rule out, I can’t say we wouldn’t be forced to do non-pharmaceutical interventions again of the kind we did.”
This marks a U-turn from Mr Johnson, who in February last year promised there would be no more lockdowns when setting out his roadmap to recovery.
He also said in October that there was absolutely nothing to indicate a new lockdown was needed.
And then in January of this year he said the Government “does not believe we need to shut down our country again”.
Lockdowns have proven to be a contentious issue for the PM, with members of his party receiving fines for attending parties during the pandemic, breaking lockdown rules.
Delving into the issues caused by locking down the country, Mr Johnson revealed the country’s obesity rates had soared.
The Government has introduced a ruling forcing restaurants and takeaways with more than 250 employees to include calorie counts on their menu.
Despite denying accusations he was introducing a “nanny state”, Mr Johnson insisted measures needed to be introduced to tackle Britain’s growing obesity problem.
He also said: “Do you know how much fatter we are post-Covid.
“I think there’s 36 percent more obesity, there’s been a huge increase in obesity.
“Before the thing began we were already the fattest nation in Europe with the exception of the Maltese.
“That is a massive charge on the taxpayer. The taxpayer is coughing up huge quantities for the consequence of that obesity.
“I’m no advertisement for will power, we need to recognise the effects of obesity on our taxes.”
It is estimated that overweight and obesity-related conditions cost the NHS £6.1billion each year.