What and how much we eat has always played a critical role in our health and wellbeing. Our immune system in particular reaps the benefits of a balanced diet, reducing your risk of contracting coronavirus COVID-19, or any other illness at any time of year.

Diet affects immune function in a number of ways, managing chronic inflammation, helping to maintain healthy weight and body fat levels, fuelling physical activity, supporting healthy hormonal functioning and so on. What diet can’t do, however, is “boost” our immune system. A balanced diet can’t improve our immune system beyond what it is already capable of.

Instead, what we can do is remove dietary obstacles that might prevent, or reduce effective immune functioning. We achieve this by creating a diet that is balanced, providing both adequate micro and macronutrients, an adequate number of calories relative to ourselves and our lives, and minimising exposure to potentially harmful or non-beneficial dietary components.

Unfortunately most people don’t know what a balanced diet is, let alone what it might look like. A balanced diet provides all beneficial nutrients in appropriate quantities. This last point is crucial, as a balanced diet technically could include dark chocolate, as it is known to contain plant flavonoids known as polyphenols, believed to positively impact systemic inflammation and brain health. That said, for some (or indeed most) individuals, consuming dark chocolate on top of a normal diet might put them in a surplus of calories, causing steady weight gain over time – a net negative, no matter how you look at it.

A balanced diet will provide enough of each of the following, without significantly compromising any single element: 

  • Calorie intake
  • Macronutrient intake
  • Micronutrient intake
  • Fluid intake
  • Adherence

But what does this look like in practice? We would argue that a balanced diet contains the following:

  • Calorie intake appropriate to your lifestyle and typical energy expenditure
  • Primarily whole, minimally processed foods
  • Regular consumption of plant foods, including fruits and vegetables (of different colours and textures), legumes, beans and pulses, plus whole grain products where appropriate
  • Regular consumption of healthy fats, including those found in avocado, olive oil, nuts, seeds, oily fish and algae products
  • Regular consumption of low fat and fermented dairy products, including low fat yoghurt, kefir and whey protein (if lactose tolerant)
  • Adequate protein intake from a combination of plant and lean animal sources including beans, legumes, pulses, lean beef and poultry, seafood and eggs
  • Adequate sodium and salt intake relative to your activity levels and underlying health conditions
  • Adequate fluid intake based on your calorie intake, activity levels, body size and so on
  • Minimal alcohol intake
  • Minimal trans and saturated fat intake (the latter is less of an issue than the former, but should still be limited to no more than 10% of daily calories)
  • Minimal highly processed food (including processed meats)
  • Minimal refined starches and added sugar

Arguably a balanced diet is, ultimately, a less “Westernised diet”. But how did we arrive at the balanced diet guidelines above? We believe that an average person adhering to the diet principles above would get all essential nutrients in appropriate quantities and have a variety of nutrient-rich food sources in their daily intake that emphasise both satiety and overall palatability.

  1. Whole, minimally-processed foods are beneficial for two main reasons. For one, they minimise the loss of nutrients in food to be consumed like fibre, certain vitamins and minerals when whole grains are refined and so on. Secondly, minimally-processed foods tend to result in lower calorie intake than highly processed foods, in part because highly processed foods allow us to harvest more calories from the food, as it is essentially already partially broken down.
  2. Plant foods provide a plethora of beneficial nutrients, including fibre important for digestive health and various satiating vitamins and minerals in high abundance. They are low in calorie density, and only moderately tasty – making them less easy to overconsume. Further, there are several potentially beneficial compounds to be found in plants, for instance polyphenols found in various fruits and vegetables (e.g. pomegranate with its antioxidant properties).
  3. Low-fat and fermented dairy products are beneficial for providing high quality protein. They are also our primary source of calcium. Fermented dairy in particular provides live bacteria that colonises the gut with a larger abundance and variety of bacteria that supports the functioning of a healthy digestive system.
  4. Achieving an adequate amount of protein is critical for supporting basic bodily functions, maintaining muscle mass and managing satiety. Different protein sources also provide additional nutrients – for instance eggs are a high-quality protein source and, arguably, one of the most nutrient dense foods there is, containing bio-available forms of choline, biotin, beta-carotene and more.

A diet with this balance of nutrients covers all essential bases, which matters when malnutrition and dietary deficiency are the leading causes of immunodeficiency in the developing world. Further, with consistent balanced dieting, we minimise the risk of health-related issues that impact immunity, including obesity, hypertension, low grade systemic inflammation and more – all issues that compromise the immune system and prevent effective innate and adaptive immune responses to foreign pathogens in the short, medium and long term.  

It is important to note that these diet guidelines are for the average person.Certain groups may been more or less at risk of nutrient deficiency (e.g. darker skinned people tend to need higher quantities of vitamin D in their diets, women are more likely to be iron deficient due to menstruation and so on). 

With respect to the immune system and dieting, there are few hacks, tips or quick fixes that we can lean on to cheat our immune system and completely avoid illness. All we can do is make sure that our diet is optimised to the point of giving us everything that we need, avoiding creating any issues within or suppressing our immune system, as well as mitigating our risk of developing lifestyle-related diseases that suppress immune function and put us at risk of illness.

From a nutritional and health perspective, a balanced diet should always be our first port of call.

Balanced recipes from our latest book

For those of you in need of inspiration in balanced, healthy eating – particularly with ingredients that aren’t perishable, or particularly hard to come by – we have selected a drink, snack and breakfast recipe from our brand new cookbook for you to try.

Drink: Rise & Shine Smoothie

Servings: 1

Preparation time: 1-2 hours

Cooking time: 0 mins

Equipment needed: Blender

Calories: 281 kCal

Protein: 26g

Fats: 5g

Carbs: 33g

Ingredients

Method

Cut the banana into slices and then freeze for 1-2 hours, or overnight ready for the morning.

Once frozen, add the banana into a food processor and add in all the other ingredients and blend until thick and smooth.

Serve over ice.

Snack: Millionaire’s Shortbread

Servings: 12

Preparation time: 1 hour 20 mins

Cooking time: 0 mins

Equipment needed: Food processor, bowl, square cake tin, saucepan

Calories: 304 kCal

Protein: 6g

Fats: 22g

Carbs: 20g

Ingredients

  • 100g coconut oil
  • 175g ground almonds
  • 25g natural peanut butter
  • 100g dark chocolate, 90% cocoa
  • 280g dates, soaked in water for a minimum of 15 minutes
  • 1 1⁄2 tbsp pure maple syrup

Method

In a food processor, combine the ground almonds with 30g of melted coconut oil and the maple syrup.

Pulse until well combined and resembling the texture of breadcrumbs.

Pour into a square cake tin lined with baking paper.

Press down firmly on the base so that it is compacted into the tin and then place in the freezer for 20 minutes.

Next, pulse the dates with the peanut butter and remaining melted coconut oil in the food processor until the mixture is relatively smooth, like caramel.

Pour the mixture on top of the base and put back in the freezer for 15 minutes to set up.

While you wait, melt the dark chocolate in a bowl over a pan of boiling water.

Pour the melted chocolate over the caramel layer and replace in the freezer for 15-30 minutes.

Once the chocolate has set, you can remove the shortbread from the tin and slice into portions. The longer you leave it in the freezer, the easier it will be to cut into even pieces.

Breakfast: Vegan French Toast

Servings: 1

Preparation time: 5-10 mins

Cooking time: 5-10 mins

Equipment needed: Frying pan, square tupperware

Calories: 320 kCal

Protein: 25g

Fats: 4g

Carbs: 46g

Ingredients

  • 15g U.P. Vegan Protein powder 
  • 100ml unsweetened almond milk 
  • 2 slices wholemeal bread
  • 15g peanut butter
  • 100g strawberries
  • 1 tsp cinnamon

Method

Mix the almond milk, cinnamon and protein powder in the Tupperware.

Soak the bread on both sides in the mixture and fry in the pan, flipping over onto the other side once one side is crisp.

Assemble on plate topped with strawberries and peanut butter.