Food and coronavirus

Examining the pandemic’s impact on the diet

An image of an empty fruit and vegetable section of a UK supermarket during the COVID-19 pandemic.

The COVID-19 pandemic and associated lockdown restrictions have affected all areas of life around the world. From travel and life plans to education, wellbeing and global economies, things are not as they once were. But how does this impact on what and how we eat? 

Self-quarantining, lockdown restrictions or the temporary closing of businesses may affect normal food habits. In some countries, fresh food has been harder to find, which can potentially lead to an increased consumption of highly processed foods.  

For some, the pandemic’s impact on diet can be deadly. According to a recent Global Nutrition Report, malnutrition is putting hundreds of millions of people around the world at increased risk from coronavirus, due to poor diets that make people in lower-income countries and disadvantaged groups within richer ones more susceptible to the virus.  

Read on to hear from our experts about the effects of the pandemic on what and how we eat. 

Inside out:

The effects of social distancing on nutritional intake

An image of a floor sign in a supermarket advising people to social distance

Kevin Walsh, a Teaching Fellow in Nutrition and Dietetics in the Department of Metabolism, Digestion and Reproduction, looks at the effect of social distancing rules on nutritional intake in the general population. Many countries around the world have advised the public to minimise the frequency of food shopping as far as possible. But how does this affect what people buy?  

“Foods with longer shelf lives appear to be an adaptive change in food choice in line with this advice. Tinning and curing often coincides with higher amounts of salt or sugar in final food products, which can impact weight and blood pressure. It remains to be seen if the relative increase in consumption of these foods will have a longer-term effect on the cardiovascular health of the nation.  

“On a positive note, many companies in recent years have reformulated their products to reduce both salt and sugar content which may give customers the best of both worlds. Frozen fruit and vegetables generally do not contain added salt or sugar so could be an even healthier option if there is access to a freezer.” 

With a large proportion of the population working from home, at home following furlough, unable to work, or self-quarantining or shielding, this also has an impact on what and how people eat, as Kevin explains. 

Food delivery and snacking behaviours in this environment could be expected to rise, adding to energy, fat, salt and sugar intake. Although these foods can be eaten in moderation as part of a healthy diet, higher than normal intake over an extended period of isolation could contribute to undesirable weight gain and increased risk of cardiovascular disease.
Dr Kevin Walsh

Choosing healthy snack alternatives such as fruit (fresh, frozen or dried), unsalted nuts, or even wholegrain crackers, and where possible preparing meals at home is advisable.” 

And what about the psychological impact of isolation? How does that affect eating? 

Kevin suggests a number of impacts:  

  • Mental wellbeing: isolation and the constant barrage of news about the COVID-19 pandemic will have significant effects on the mental wellbeing of the population.  
  • Appetite: Such an environment may also impact on people’s interest in food; for some a loss of appetite and reduced food intake, while for others an increase in stress- or comfort-eating.  
  • Physical health: Both of the above will have negative impacts on health which could include undernutrition or conversely weight gain and increased risks associated with this. 
  • Drinking: Alcohol consumption may also rise in this environment, further affecting psychological wellbeing and contributing to increased risk of weight gain.  

Aside from effects on food choice, lockdown orders and gym closures make taking physical exercise more fraught, states Kevin. Coupled with possible increased intake of high-calorie snacks, takeaway foods and alcohol, a reduction in physical activity will further contribute to weight gain and possibly low mood.  

“As such it remains important to include some physical activity daily, indoors or outdoors in line with government advice,” he suggests. 

“Currently, general dietary advice remains in effect: eating a wide variety of foods, taking at least five portions of fruit and vegetables daily, including high-fibre starchy foods at meals along with adequate protein sources while limiting foods high in salt, saturated fat and sugar.” 

A cupboard shelf with pasta, rice and lentils
Hands taking slices of pizza from a takeaway box

Older people:

Maintaining good nutritional intake during lockdown

An elderly man holding a walking stick

Older people, especially those with an underlying medical condition, are at a greater risk of morbidity and mortality from COVID-19. According to Professor Gary Frost from the Department of Metabolism, Digestion and Reproduction, one of the drivers for this vulnerability appears to be an abnormal immune response to the virus. 

“During the incubation and non-severe stages, a specific adaptive immune response is required to eliminate the virus and prevent disease progression to severe stages. When this protective immune response is impaired the virus will propagate which could lead to the devastating consequences of the illness. Therefore, it would appear important to ensure a robust immune system prior to exposure to the virus.” 

The effects of ageing on immunity are complex and occur at many levels of the immune system – this results in elderly people not responding to immune challenges as well as the young. This can be compounded by poor nutritional intake. Poor nutritional status in older people is common with a fifth of older adults experiencing undernutrition.   

According to Professor Frost, this is driven through a complex array of issues such as age-related changes in taste, comorbidities and concurrent use of multiple medications, combined with social factors or depression leading to a reduced appetite. Those older people most at risk are:  

  • People living in deprived areas 
  • Those who are socially isolated 
  • People with chronic disorders such as chronic obstructive pulmonary disease or cognitive impairment 
  • And those who were recently hospitalised   
Although it is not possible to change the effects of advanced age it is possible to improve nutritional intake. However, COVID-19 brings new challenges to maintaining good nutritional intake in the most vulnerable in society.
Professor Gary Frost

"Self-isolation is critically important in reducing the risk of exposure to COVID-19, however it can also enhance apathy to many things including food and can lead to poor nutritional intake."

He goes on to highlight that access to a supply of nutritious food can be extremely challenging with the strain on the supply of food brought about by panic buying. This coupled with decreased ability to shop because of self-isolation can lead to poor food supply in the home, especially if there is little or no internet access to order food. 

Therefore, Professor Frost concludes, “thought needs to be given to some very fundamental needs to maintain nutritional intake in older people”.  

Ensuring good nutritional status in older people cannot overcome the effects on the immune system due to advanced years. However, a good food supply can mitigate the effect of undernutrition which affects large numbers of older people and suppresses immunity further. 
Illustration of virus and antibodies
An elderly couple walk in countryside

Vulnerable groups:

A disproportionate nutritional burden

A person serving food at a soup kitchen

According to a recently published Global Nutrition Report, malnutrition is putting hundreds of millions of people around the world at increased risk from coronavirus, with warnings that global hunger could double because of the pandemic. Dr Modou Jobarteh, a Research Associate in the Department of Metabolism, Digestion and Reproduction, argues that the lockdown poses a disproportionate nutritional burden on society’s poorest populations and there is a need for a COVID-19 food and nutrition preparedness plan.   

The lockdown advice has significant implications on diet and nutritional health, with the most impacted being the vulnerable and poorest, such as the homeless, low income families and the elderly. This poses a significant adverse effect on the long-term health of the affected people.
Dr Modou Jobarteh

Efforts have been made by councils and charities in parts of the UK to provide housing for the homeless. The efforts are further complemented by the delivery of food bags to those in need. In addition, food vouchers valued at £25 per child are distributed fortnightly to low income families with school-going children and who are already entitled to free school meals.  

“Whilst these are laudable efforts,” Dr Jobarteh says, “the UK government and local councils should quickly put in place a concerted effort to ensure no one is left behind.” 

So what should that effort look like? Dr Jobarteh suggests three main steps:  

  • A comprehensive COVID-19 food and nutrition preparedness plan should be enacted to ensure minimal-to-no disruption of food supply to UK households.  
  • This plan should highlight strategies for protection of food production from farm to fork.  
  • Adequate support should be provided to farmers who might have lost valuable manpower around their farms to ensure the continuous production and distribution of foods. 
  • Government and councils should work with supermarkets and other food vendors to ensure there is no unnecessary inflation in the prices of essential food stocks. 

Further support, beyond the current £25 weekly food voucher, should be provided to low income families to increase the availability and consumption of healthy nutritious diets, especially families with nutritionally vulnerable individuals, such as children under the age of 5 years, adolescents, pregnant women and elderly. 

Looking beyond supporting those in need in the UK, Dr Jobarteh says: “The UK government should maintain, if not increase, its commitment to supporting the nutritional health of populations in low- and middle-income countries through the Department of International Development (DFID), and charities that provide such support. In the present circumstances, leaders of the G7/G20 block of nations should fosters a tighter collaboration to support and maintain an undisrupted global food production and supply in any way possible.” 

A vulnerable woman begs for money on a busy street

COVID-19 and planetary change:

The food system is sick

An area affected by deforestation with trees chopped down

Looking ahead, could reforming the food system overall prevent future pandemics? That’s what Professor Paolo Vineis, Chair of Environmental Epidemiology at Imperial’s School of Public Health argues.  

“Agricultural practices like intensive farming and extensive animal breeding have led to widespread deforestation and a lack of control over how land is being used or misused (like we are seeing in Brazil). As a result, around 26% of global greenhouse gas emissions (GHG) now come from the agriculture sector. In the Global North, this system has also encouraged poor diets, such as eating lots of processed food and excessive amounts of meat. These types of diets are associated with chronic diseases, like diabetes and cardiovascular diseases, which, in turn, make people more vulnerable to the worst impacts of COVID-19.” 

Animal farming has also created conditions that make it easy for RNA viruses like COVID-19 to spread. As agriculture increasingly encroaches upon the wilderness, humans come into closer contact with more wildlife and so there is a heightened risk of viral species being able to infect humans.  

Professor Vineis thinks that reforming these agriculture practices and the world’s unsustainable food system could prevent future pandemics and create a more sustainable and resilient future.  

Cows in a milking shed

During a pandemic, excessive purchases made by some people brings about shortages of some food items in supermarkets – as seen in the early days of COVID-19 in the UK and other countries. Many of these food items will not be consumed and consequently, food waste will be generated.  

Jerusa Brignardello, Research Postgraduate in the Department of Metabolism, Digestion and Reproduction, recommends that it is key to plan your menu in advance and be flexible about availability of food items. Here are some of her tips:

What's next?

It is clear that the pandemic and associated lockdown and social distancing measures put in place have affected how and what people eat. As lockdown eases, restaurants start to open and supermarket shelves become filled, eating behaviours are slowly becoming more normal. For the most vulnerable however, this may be more than just a temporary change.