I stopped wearing sunglasses during the day, and only wear them in the evening when I’m inside (my friends think I’m weird and people ask me if I sell drugs).


Here’s why:
This is a story about how stumbled into the fascinating world of circadian health and quantum biology.
Since then, I have become my leanest and strongest self. I haven’t worn chemical sunscreen in 2 years and I’ve had the best tans of my life without getting sunburnt (except once after two hours in peak Indonesian sun).
I did this living in my 7th year of living in the UK after 16 years living in a tropical country, during which I only ever burned or turned a weird ashy colour.
Lifestyle makes a massive difference to how your body receives sunlight.
There we were in a barn near Lewes, about to be served one of the most delicious and nutrient-dense meals of my life. I see a man wearing vivobarefoots (they tend to stand out) and yellow-tinted glasses. I found the glasses a bit strange considering the sun was still out and we were inside.
Later that evening I would know this man to be Dr Ed Caddye (@DrEdCaddye), a decentralised medicine practitioner specialising in health optimisation.
Sat next to him at dinner, I asked him “What is the optimal human diet?”
“Well.“ he said. “It depends on where you were born and what time of year it is.”, looking at me through his yellow-tinted glasses.
What?
I was certain he’d give me some combination of the Atkins, ketogenic, or carnivore diet because this is what I believed (and I’m always right).
In hindsight, it makes complete sense that there isn’t one solution and it seems obvious that it would depend on your environment. But at the time it hadn’t occurred to me.
I queried him further. He explained how your light environment and the time of year determine what foods you should eat. Your light environment in the region you’re born determines what foods may or may not be suitable for you.
He went on to explain why.
Most of us are familiar with the food web, and how energy from the sun works its way up from plants to us. Food is stored sunlight.

It’s also information. Your food is one of the many ways your body gathers information about its environment.
Viewing food as information rather than just raw building material for your body completely changes the meaning of a ‘healthy’ diet.
Most of us understand that carbohydrates do not grow in the winter unless you grow them under artificial light. Therefore it would make sense, if you wanted to work with your body’s natural rhythm, to avoid carbohydrates in the winter and primarily live off proteins and fats.
Consuming carbohydrates in the winter would mean consuming food that was not grown under the same light that you live under. You’re giving your body mixed signals.
In equatorial regions where it’s sunny all year round, carbohydrates are abundant. So it wouldn’t make sense for a metabolically healthy person living in these regions to avoid carbohydrates.
I, and most people at the table, had heard of Dr Andrew Huberman (@hubermanlab) and were avid listeners of his podcast. Dr Ed pointed me to a 2 part podcast totalling 7 hours, with Dr Jack Kruse (@DrJackKruse), Dr Huberman, and Rick Rubin.
Dr Jack Kruse takes us on a 7-hour journey through natural history, stopping occasionally only to answer questions and verbally abuse Huberman (his delivery is on the abrasive side).
The fundamental premise of the story:
Nature doesn’t make mistakes in the long run.
Each species is an AI model that has been trained over hundreds of millions of years to figure out what features have the highest chance of survival in its natural environment.
Who are we to say we know better?
Perhaps we would all benefit from simply trusting that nature has prepared us for our environment, and integrating our natural rhythms into our modern lifestyle as much as we can.
That meeting with Dr Ed in that barn, and that 7 hour podcast, woke me up to how important your light environment is, and how centralised medicine has neglected this critical aspect of our lives. It has also led me down a path of living a life more in tune with other aspects of my environment, like the ground.
Everything I’ve learned since then has helped me improve my life by developing a simple approach to improving metabolic health which has ultimately made it easier to become stronger, leaner, and feel better overall. To be explored in future posts.
This is the podcast between Dr Huberman, Dr Kruse, and Rick Rubin. If you have 7 hours to spare, it’s a good listen.