Are you a creature of habit when it comes to food?

Let’s face it: most of us are. Left to my own devices, I would walk around the shops on autopilot most weeks, purchasing broccoli, peppers, carrots, romaine lettuce, tomatoes, a cucumber, apples, bananas, eggs, chicken, bacon, some beef mince, cod, salmon, oatcakes and a couple of tubs of hummus. Occasionally, I would have to stock up on some olive oil, apple cider vinegar, herbs and spices and that would be pretty much it. It’s always the same, or rather it would be, if I didn’t make a conscious effort.

An organic vegetable box subscription takes care of the veg. Although it can get a bit boring sometimes in the winter months, there is still more variety what I might otherwise buy, sometimes unusual vegetables you don’t very easily find in the shops, which is always a treat. Veg box companies such as Abel & Cole also do combined fruit and vegetable boxes, of course, but I’m not that big on fruit and rather buy it as and when I need it. You can even get meat or fish or meat and fish boxes, although that can get a little pricey.

But what’s my point? Why am I always going on about food variety?

First of all, of course, variety keeps things interesting. But there’s a more important reason: our gut microbiome.

I have written before about what our gut microbes do for us and why they are so important (click here to refresh your memory). However, I only touched on variety at the time.

Since researchers have been able to identify the bacteria that live on and inside our body by mapping their genomes, many more different species have been discovered than we knew about before. That’s because a lot of species are unable to live in an oxygen environment – they are ‘anaerobic’, which means that they die as soon as they come into contact with oxygen and can therefore not be grown as a culture in a lab.

We now know that there are at least 1,000 different species, and who knows how many more will be discovered in years to come? Every person’s microbiome is as distinct as a fingerprint – but not as durable. Our bacterial population changes all the time, depending on where we live, who and what we touch, which medication we are on, and many more factors, including – of course – what we eat.

There’s a lot still to learn about the microbiome. So far we certianly know that we cannot be healthy without bacteria and that the healthiest people are those with the largest variety of different species. And that variety is not achieved by taking probiotic supplements – those are very limited in the variety of bacteria they contain – but by variety of the diet!

Different species have different preferences, some are as fussy as a panda bear and will only eat one type of food. Our gut bacteria depend very much on what we give them, and if our diet is limited, so is whatever remnants reach the colon where they reside. When our diet changes – say, if we switch from an omnivorous diet to a vegan one – the composition of our bacterial population is going to change within days.

Most of us imagine that the diet of our hunter-gatherer ancestors must have been rather boring. After all they didn’t have access supermarkets with thousands of different food products in them, did they? But that’s where we’re wrong. In fact, hunter-gatherers would eat on average 150 different foods per week. We, however, in the 21st century in the Western world, eat only about 20 different foods per week. The majority of those foods in the supermarkets are processed foods, most of which are based on just four ingredients: corn, soy, wheat, and meat. A hunter-gatherer would have eaten a selection of different roots, fruit, vegetables, fish, seafood, eggs (of all sorts of birds), meat, nuts and seeds, which would have been dependent on the location, the season, and their luck. On average, Westerners give a home to approximately 150 to 200 species of bacteria. The indigenous population of the Amazon delta, however, carry at least 300 to 400 species.  

If you would like to find out how varied your own diet is, why not track your food variety for a few weeks? Draw a table with 50 boxes on an A4 sheet, stick it to your fridge and fill the boxes with the different foods you eat in a week. Make sure that they are actually different: For hummus, write ‘chickpeas’, if you have chickpeas in your soup the next day, you can’t count them again. Same for bread, croissants, or crumpets: you can only fill one box and that’s with the word ‘wheat’. I’ve made such a table for you, which you can print and use. To download, just click here.