Has COVID changed the way we eat?

January 25, 2021

This article has not been updated recently

In October we set out to understand how the COVID-19 pandemic has changed the way we eat and live. 

We assembled a team of expert scientists from Massachusetts General Hospital, Stanford University and King’s College London to launch a validated diet and lifestyle survey - and over 1.5 million of you took part, making it the world's largest study into diet and COVID-19.

Here’s what we learned from the study so far:

One size doesn't fit all: the pandemic impacted each of us differently

What's clear is that changes to diet and lifestyle during the pandemic look very different for all of us. We saw no significant changes across the study population as a whole, but there was considerable change at an individual level.

Four in ten people experienced a change in their diet quality during the pandemic, some for the better and some for worse. More people increased (15%) than decreased (8%) their alcohol consumption, while more people increased (15%) than decreased (10%) their fruit and vegetable intake.

What's caused our diets to change? 

A number of papers have been published suggesting possible reasons for diet and lifestyle changes during the pandemic, many of which were also found in our own study:

Assessing the diet quality of study participants

We calculated personalised Diet Quality Scores (DQS) using a scientifically validated method that has been shown to effectively assess diet quality. 

This work was conducted using the Short Form Food Frequency Questionnaire (SFFFQ) tool developed by Cleghorn as reported here and listed in the Nutritools library.

The DQS score indicates how 'healthy' your diet was before and during the pandemic, based on your survey answers. A higher score indicates a 'healthier' diet that includes plenty of fruits and vegetables, while a lower score could indicate a less healthy diet that includes more processed meats, high-sugar foods, and fried snacks.

The DQS is a very simple way to understand diet quality for the 'average' person, based on general healthy eating advice. As individuals it’s clear that we all respond to foods in slightly different ways, which means that there isn’t one 'healthiest' diet for all of us.

Personalising diet quality

To share more personalised feedback, we leveraged the expertise of leading scientists and findings from our microbiome research to develop the Gut Friendly Diet score (GFD). This score was designed to show how your diet affects your gut microbiome. We are using the first version of this score, which hasn’t been validated yet but is currently being refined using data from one of our research programs, called PREDICT.

There’s a large body of research suggesting that the human gut microbiome plays an integral role in our immune and overall health. Through our PREDICT program of research, we’ve discovered that each of us has a unique gut microbiome, which is directly impacted by what we eat.

What does my gut friendly diet score mean?

Your personalised GFD score indicates the ratio of gut 'friendly' to gut 'unfriendly' foods in diet before and during the pandemic, based on survey responses. A better score suggests that you have a balanced diet containing more gut 'friendly' foods (e.g. fruits, vegetables, beans, fermented foods), which are associated with a higher number and diversity of 'healthy' gut microbes. 

A lower score suggests that your diet lacks enough ‘gut friendly’ foods, which may not support the growth of 'healthy' gut microbes. Your diet might also include higher amounts of gut ‘unfriendly’ foods (e.g. fast foods, sweet treats, and red meat).

This score provides an estimate of your gut health based on an understanding of the types of foods that are linked to a healthier gut microbiome. 


The Diet Quality Score (DQS) and Gut Friendly Diet (GFD) score were created for general information purposes only. They are not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition.

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