Personalised healthy eating

Originally written for LawTalk Magazine, published 8 March 2019

With a demonstrated positive association between psychological distress, disordered eating, weight and shape concerns and maladaptive eating habits, it’s clear that stress, anxiety and depression are linked to unhealthy eating and taking control of your eating habits can lead to not only better health but also better mood and less stress on your body.

When it comes to being ‘healthy’, or, more specifically, ‘healthy eating’, there’s so many options to choose from, it’s easy to get confused. How do we know if we should be intermittent fasting or eating 6 meals a day, if we should be paleo, plant-based or ketogenic?

If we want to start eating healthy, where do we start?

Firstly, I think we can all agree that some simple common-sense guidelines are still relevant:

  • Drink 8 to 10 glasses (2 litres) of water each day, filtered if possible
  • Include all macronutrients (carbohydrate, fat, and protein – whether plant or animal based) in all your diet
  • Focus on unprocessed wholefoods
  • Vary your fruit and vegetables from day to day and week to week – try to eat according to the seasons
  • Avoid refined, highly processed foods, especially those that include additives like MSG, sugar, white flour, poor quality salt and vegetable oils

These general strategies give us a great starting point, however, when we get into the detail of what’s going to work best for each of us, the answer may lie in our genes (genotype), or more accurately, our epigenome and our phenotype.

The epigenome is a sheath of proteins and chemicals that sits on top of our strands of DNA which can modify how that DNA is expressed. The epigenome can switch on and off genetic traits like a light switch according to our experiences, perceptions and lifestyle choices.

The phenotype is the result of the complex interactions between our genotype, the environment we’re in, and our lifestyle choices, leading to the expression of those genes, or the person we are, right now.

As an analogy, if your genes are the music of ‘you’ as it’s written, your epigenome are the sound engineers, determining which bits are loud and which bits are soft, which bits get the spotlight and which bits gets ignored. Your phenotype is the symphony we hear.

Since the human genome was mapped in 2003, with the promise of solving major health issues, it’s been discovered that only around 20-40% of our health is down to our genes. 60-80% is reliant on gene expression or our phenotype, that is, the multifaceted interplay of the environment and our choices on our genes. For example, you may have a genetic predisposition for diabetes, but that doesn’t necessarily mean you will develop diabetes. Your lifestyle choices have a very real impact on which genes in your body ‘switch on’ and therefore on the quality of your health and your life.

One of the most important factors for your gene expression is the food you eat.

I’m sure you’ve all witnessed two people on the same diet with vastly different results. You may have assumed that one person may have tried something else and kept it a secret or that the other person ‘cheated’. However, it’s becoming clear that we all respond differently to different diets depending on our genes and how they are expressing.

For each of us there are specific foods that will benefit us more than others, there are meal timings, frequencies and portion sizes that will encourage our best health more than others. Some people will do better focusing on mostly plant-based and fewer meals while others will thrive on a higher protein intake and more frequent meals.

This concept is fast becoming more mainstream. The Global Wellness Institute released its 2019 Global Wellness Trends recently and identified personalised nutrition as a top trend that will have a meaningful impact on the $4.2trillion wellness industry.

David Bosshart, CEO of independent European think tank GDI Gottlieb Duttweiler Institute for Economic and Social Studies and keynote speaker at the 2018 Global Wellness Summit states “We are confused about what we eat, where we eat, and when to eat it. We define ourselves by what we’re eating, but, even more so, by what we don’t eat… we are overwhelmed by our choices.”  The question needs to change from ‘what foods are right for us’ to ‘what foods are right for me’.

Enter epigenetics and phenotyping to give us an answer.

What works best for each of us is based on many things from our embryology through to our phenotype, the hormones that are dominant in our system and the symptoms we may be experiencing.

You can easily get your genes tested to see if you’re predisposed to certain conditions but what’s more important is whether those genes have been switched on or not and how to beneficially control them. Preliminary studies are also showing that individuals are more likely to stick with personalised nutrition advice based on phenotyping.

And it doesn’t just come down to diet, other things that affect gene expression come as no surprise:

  • Exercise
  • Sleep
  • Stress management
  • Medication/supplements
  • Sense of purpose and meaning in life

As well your epigenome and phenotype, your microbiome also plays a significant role in your overall health and mood and is also affected by your food choices.

The microbiome is the trillions of bacteria and microbes that live in your gut. That’s around 1-2kg of bacterial cells with various roles in the body and they far outnumber the human cells in our body. There’s up to 1000 species of human gut bacteria and your personal microbial make up is as unique as your fingerprint.

A diverse range and high population of gut bacteria is vital for good health, affecting:

  • Digestion and absorption of calories and nutrients from food
  • Digestion of dietary fibre which produces chemicals that benefit gut health and affect weight loss
  • Fat absorption and sensitivity to insulin, impacting on fat storage
  • The production of hormones leptin and ghrelin, which control appetite and motivation to eat

In addition to this, up to 90% of your happy mood neurotransmitter serotonin and 50% your feel-good neurotransmitter dopamine reside in your gut, so a healthy gut and microbiome is essential for better mood and ability to cope.

Studies have shown that lean people generally have up to 70% more gut bacteria and more diverse gut bacteria than overweight people. A typical Western diet that’s high in fat and refined sugars but low in fibre commonly leads to less microbial diversity.

While your gut microbiome is to some extent affected by genetics, the following lifestyle and dietary habits can help to promote more beneficial microbes over harmful ones.

  • Increase fibre intake to encourage healthy gut bacteria like bifidobacteria which can help weight loss. Most high fibre foods, like fruit, vegetables and wholegrains, also contain prebiotics which your gut bacteria breaks down for fuel to promote more beneficial bacteria.
  • Focus on a variety of wholefoods for a more diverse microbiome.
  • Increase polyphenols like green tea, dark chocolate, olive oil and wholegrains. Polyphenols are type of antioxidant that your microbiome breaks down to help make more healthy gut bacteria.
  • Eat fermented foods like yoghurt, sauerkraut, kimchi, kombucha and kefir which contain probiotics and healthy bacteria that promote can control the number of disease-causing bacteria in the gut.
  • Reduce chronic ongoing stress as it slows gut function. Gentle exercise likes Vinyasa yoga, walking in nature, meditation, breathing exercises or mindfulness techniques can help.

While there are general guidelines for healthy eating, it’s clear there’s no one-diet-fits-all prescription and the plethora of diets that ‘work’ is testament to this.

Find out what works best for you by listening to your body and using your intuition to tune into your own hunger and fullness signals, being mindful of the foods you eat, how you feel afterwards and making adjustments accordingly or alternatively talk to me about epigenetic profiling for a greater understanding of how to eat, exercise, live and work in congruence with your body.