Exercise and eating a good diet is healthier than being sedentary and eating processed foods. Why though?

Is there a model of health that can explain why exercise is healthy for us?
Will this model allow us to predict other activities that promote health and happiness?

One model that accurately predicts health is living like a hunter-gatherer.

A hunter-gatherer is a human living in a society in which most or all food is obtained by hunting: pursuing wild animals, and gathering: collecting wild plants.

Our bodies evolved over millions of years where hunting and gathering was the dominant way of life.

This is a lot of time for evolution to reward those hunting and gathering activities that lead to survival and reproduction.

The way we get our food has changed greatly throughout history.
The three main ways humans have got food:

  1. Hunting and gathering
  2. Agriculture
  3. Agriculture & Technology <-- today

Visualising this

A timeline from this blog that shows just how long we were doing this hunting and gathering thing.

Hunting and gathering was humanity’s first and most successful adaptation, occupying at least 94% of human history.

There is evidence of our ancestors hunting and gathering as far back as 2 million years ago. When we (homo sapiens) appeared 200,000 years ago hunting and gathering was still the dominant way of life. It stopped being the dominant way of life around 12,000 years ago with the move to agriculture.

I’m using 120 years ago as the introduction of refined processed foods, enabled by improvements in technology.

If we include our ancestors:
Hunting and gathering = 99.4%
Agriculture = 0.6%
Technology = 0.00006%

If we only include humans (homo sapiens):
Hunting and gathering = 94.3%
Agriculture = 5.7%
Technology = 0.0006%

That’s a lot of time to adapt us to hunting and gathering!

Here are some examples of health advice, and how they match those hunter-gatherer activities that lead to survival and reproduction:

  • Exercise. It boosts physical strength, makes you happy, lose weight, increases your energy levels, improves brain function, memory and sleep (1)
    It was beneficial for hunter-gathers to be at their best while finding food. Exercise is analogous to hunting and foraging… here, have some BDNF to improve your brain function for the hunt. Exercise use to happen naturally. It was tied to our survival.
  • Walk 10,000-15,000 steps per day (2)
    Same thing. Hunter-gatherers walked and hunted for food. Their survival depended on being active.
  • Intermittent fasting(2)
    It increases BDNF and attention. I’m going to give your brain a boost to give you the best chance to find food.
  • Eat fruit, vegetables, small amounts of lean protein and fish (3)
    Hunter-gather diet.
  • Avoid processed foods, added sugar and bad fats (4)
    Our bodies are not adapted to eating lots of added sugar, fat and processed food. We feel good when we eat these things because it used to be hard to find calorie dense foods like honey. When we did we were rewarded with a surge of dopamine (survival and reproduction neurotransmitter). Energy dense foods are good for survival.
    Today we can easily get these dopamine hits because sugar and fat is everywhere, and cheap! This adaptation no longer serves us.
  • Sun exposure produces vitamin D, lowers cortisol, increases serotonin and dopamine (5)
    Hunting and foraging in the sun.
  • Being in nature makes us happier and more creative (6) 
    Hunter-gatherer life.
  • We learn best through trial and error (7)
    Hunter-gatherer learning is practical.
  • We are social animals and feel happy when we help each other (8)(9)
    We are adapted to live in close communities of about 150, as our hunter-gather ancestors did.
  • Minimalism (10)
    Hunter-gatherers were nomadic. They moved where the food was.
    They could not carry a child, a 60″ TV, two wardrobes of clothes etc. Could be why we feel free when we own less stuff.
  • Sleep (11)
    Before the invention of artificial light – which suppresses the sleep hormone melatonin – we were more likely to get better sleep.

That we’re born with Hunter-gatherer bodies into an environment that’s so different to the one we’re adapted to explains today’s mismatch diseases.

If you want to read more here are two great books on the subject:

References

  1. http://informhealth.com/neurotrophins-fertilisers-for-your-brain/
  2. http://www.health.com/heart-disease/how-many-steps-a-day-prevent-heart-disease
  3. https://edition.cnn.com/2017/07/05/health/hunter-gatherer-diet-tanzania-the-conversation/index.html
  4. https://www.theguardian.com/science/2013/sep/22/dieting-disaster-evolution-daniel-lieberman
  5. https://www.selfhacked.com/blog/avoiding-sun-will-kill-14-proven-science-based-health-benefits-sun
  6. https://greatergood.berkeley.edu/article/item/how_nature_makes_you_kinder_happier_more_creative
  7. https://www.psychologytoday.com/blog/freedom-learn/201105/the-human-nature-teaching-ii-what-can-we-learn-hunter-gatherers
  8. https://www.theguardian.com/technology/2010/mar/14/my-bright-idea-robin-dunbar
  9. http://www.cracked.com/article_14990_what-monkeysphere.html
  10. http://www.greenhighfive.com/did-we-evolve-to-be-minimalist
  11. https://www.health.harvard.edu/staying-healthy/blue-light-has-a-dark-side