In a video on Thursday, the British PM said he has "been doing a lot, in fact everything I can" to "lose weight and to feel fitter and healthier" during the Covid-19 lockdown, adding that he feels "much more energetic" because of it.

"I feel full of beans, and I thoroughly, thoroughly recommend it," Johnson declared, before concluding that he wants to "encourage” hundreds of thousands of others around the country to get "healthier and happier" with him.

Johnson said the government has pledged £100 million to initiatives which seek to lower obesity numbers, including by creating apps to help people lose weight and possibly introducing 'Fit-Miles' schemes.

Many on social media did not take kindly to Johnson's video, however, accusing him of being tone-deaf as most regular people have not had access to facilities like gyms and pools for months due to lockdowns.

Several Twitter users pointed out that while the government ordered health facilities like gyms to close, unhealthy fast-food takeaways remained open and became appealing to people who could not leave their homes or go to healthier restaurants. Others pointed out that Brits who decided to exercise outdoors were in some cases harassed and sanctioned by police.

"You couldn't have done more to make people unhealthy – lock them down, close gyms, limit exercise, encourage takeaway food, fail to recommend vitamins etc,"protested one person.

Others, like the University of Edinburgh's Global Public Health Chair Devi Sridhar, took shots at Johnson's upper-class privilege.

"So we just need to give everyone in the country their own personal trainer, time to exercise instead of working & a monthly voucher to Waitrose for fresh fruit/veg? That could work!" Sridhar mocked in a since-deleted tweet.

Angry commenters on social media are not the only ones concerned about the impact of lockdowns on the public health. UK health experts have also been warning that the pandemic restrictions are leading to a rise in obesity which could affect health long after Covid-19.