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11 February 2021

Lockdown used by those with unhealthy lifestyles to get healthier

According to the largest study of diet and lifestyle behaviour during COVID-19, the disruption caused by lockdown restrictions spurred many people, particularly those individuals who had less healthy behaviours before the pandemic, to make improvements to their diet and lifestyle.


These findings are contrary to the popular belief that the COVID-19 pandemic has had only negative impacts on health behaviours.

In order to understand how the pandemic has affected health behaviours, a team of King’s researchers led by Dr Sarah Berry and Professor Tim Spector, together with data scientists from ZOE, analysed responses to a detailed diet and lifestyle survey collected from more than one million users of the ZOE COVID Symptom Study app in the UK and US, before (Feb 2020) and during (July/ Sept) the pandemic.

The study found that two thirds of people experienced some level of diet and lifestyle disruption, measured using a novel health disruption index[*]. The research also found the greatest disruption to health behaviours was seen in young females and those living in more deprived areas and was associated with a more variable change in weight, both weight loss and weight gain. These findings raise the question of whether the weight loss seen in these more vulnerable groups is always a positive thing.

The research also highlights issues around food security, with four times as many participants experiencing decreased access to food, compared to those for whom food access improved. Echoing these findings, independent charity, The Food Foundation found that 5.1 million UK adults (9.7%) experienced food insecurity in the 6 months to August 2020, a significant rise from pre-pandemic levels.[1]

According to the research, individual responses and changes to health behaviours varied greatly:

  • 32% of participants lost an average of 4.0 kg, while 34% of participants gained an average of 3.5kg.
  • 33% of participants increased their fruit and vegetable consumption (from 3.5 to 5.6 portions/day), compared to 23% who decreased (from 5.6 to 3.8 portions/day).
  • 22% of participants reported snacking less, compared to 18% who increased their snacking.
  • 18% reported an increase in the frequency of alcohol consumption, compared to 11% who decreased. However, there was a decrease (14% decreasing vs 11% increasing units) in the amount consumed at each event, suggesting total alcohol consumption may have been unchanged.
  • 27% of participants reported an increase in exercise, compared to 25% who were less active.

The COVID-19 pandemic has created a unique global situation in which most of the world has experienced major lifestyle disruptions. This study shows the huge individual variability in how we have changed our diet and lifestyle behaviours during the pandemic. There is a perception that the disruption has had a negative impact on health behaviours and body weight, but our research shows that this is not the case for the majority of the UK and US population. In fact, the pandemic may have provided an impetus for many people to make changes to improve their diet and adopt a healthier lifestyle.

Study lead Dr Sarah Berry, from the Department of Nutritional Sciences

Rebecca Tobi, registered associate nutritionist and programme manager at The Food Foundation comments: “The impact of the pandemic on our food choices and the wider food environment continues to evolve, but for many it has certainly been a sea change. While for some, Covid-19 has meant more time to cook, try new things, and exercise more, for others it has meant a loss of income, heavy childcare commitments, and real issues with being able to access and afford enough food. This new research really highlights the different effects the pandemic has had on us all, and how when it comes to individual experience, it’s very much been a tale of two Covid’s”

Professor Tim Spector, professor of genetics epidemiology at King’s, said: “The COVID-19 pandemic has pushed health to the front of everyone’s minds. For the first time we have been able to ask millions of people key questions about their health and lifestyles choices. Doing research like this on such a big scale via the COVID Symptom Study will help us understand how and why people change health behaviours such as diet and exercise.”

Dr Rachel Gibson, Registered Dietitian and Lecturer in the Department of Nutritional Sciences at King’s College London, said: “In this study we found that for a section of the population, changes in eating patterns and reduced activity were associated with weight gain. Whilst weight alone is not always a reliable indicator of health, previous research has established that living with overweight or obesity, compared to a healthy body weight, can increase the risk of developing type 2 diabetes, cardiovascular diseases and potentially serious illness or death from COVID-19. With around two thirds of the UK adult population living with overweight or obesity further research will be important to understand the reasons why people changed their lifestyle behaviours during the pandemic, this will help focus future public health interventions.”

The paper is under peer review at Nature Journals / DOI 10.21203/

All this research was discussed on a live webinar on the ZOE channel:

In this story

Tim Spector

Professor of Genetic Epidemiology

Rachel  Gibson

Senior Lecturer