Research carried out for Public Health England (PHE) found 41% of adults in England said they had put on weight since the first lockdown in March last year.
The survey of 5,000 people found around half a stone (4.1kg) was gained on average by those who put on weight, with 1 in 5 (21%) reporting putting on a stone or more.
In adults aged 35 to 65 years old, the average weight gain for those who put on weight rose to over 10lbs (4.6kg).
Unhealthy eating habits, like snacking and comfort eating, were reported as the main contributor to weight gain during the pandemic for nearly half (46%) of those who reported gaining weight.
It comes as a new campaign is launched to help people eat better and get fitter with more research finding people who use and follow the NHS Weight Loss Plan app over 12 weeks reported a loss on average of almost a stone (5.8kg).
Public health minister Jo Churchill said: “The pandemic has been hugely challenging for everyone and it has upended our daily routines. As we build back better in the months ahead, we want to make it easier for people to adopt a healthier lifestyle that works for them.
“The brilliant Better Health campaign returns today and provides a wide range of tools – including an easy to use phone app – to support people, whether that’s losing weight, sharing healthier recipes or motivating people to be more active.”
:: Search ‘Better Health’ or visit nhs.uk/betterhealth for free tools and support to start leading a healthier lifestyle.