The ZOE COVID-19 Study recently shared their findings linking the quality of our diet to COVID-19 risk and the severity of COVID symptoms. Those categorised as following a ‘high quality diet’ were less likely to catch COVID-19 compared with those that were categorised as following a ‘low quality’ diet. Those in the highest quality eating group were also significantly less likely to get severe COVID-19 symptoms and be admitted to hospital.  

What do we mean by a ‘high quality diet’? High-quality diets were classified in the study as diets that included lots of plant-based foods; including fruits, vegetables and whole grains, along with foods that support a healthy microbiome in the gut. A low-quality diet, in comparison, was defined as containing ultra-processed foods, including cereals, breads, confectionary chocolate and fizzy drinks.  The researchers rate each food as a percentage (with 100% being the highest quality food and the least processed). For example,

A donut has a score of 3% (which can be enjoyed once in a while)

A slice of shop bought bread has a score of 28% (which can be enjoyed in moderation)

A piece of cheese has a score of 71% (which can be enjoyed regularly)

A portion of broccoli gets a score of 100% (which can be enjoyed freely)

Combining foods also affects scores, for example mayo with tuna and lettuce has a score of 53% but when combined with white bread brings the score down to 25%. 

The researchers have further developed their concept by devising a very clever app designed with individuals’ metabolic needs in mind.  As each food has a metabolically different effect on each person, they have consequently developed an array of tests to assess blood sugar, gut health and blood fats which then allows them to predict a unique score for each food in terms of how it impacts an individual.  This could be extremely useful in helping people to achieve an optimal score daily and consequently improve their health and risk of COVID-19 complications. 

Here are my top tips for achieving a high-quality diet…

Consume 9-10 fresh or frozen vegetables daily with good variety

Choose complex carbohydrates such as brown rice, quinoa, buckwheat, oats, legumes

Include essential fats such as olive oil, nuts and seeds, oily fish, avocado

Choose clean proteins such as lean meats and fish, legumes

Include probiotic rich foods, such as sauerkraut, kefir, kombucha tea

Ensure good levels of fibre and prebiotic rich foods to provide the fuel for healthy bacteria in the gut such as leeks, onion, asparagus, oats, bananas, flaxseeds, apples, konjac root.

The researchers were also keen to point out that if the diet is dominant in high quality foods, low quality foods could be tolerated well in small amounts. So you can indeed eat a little of what you fancy….