Why are we fat? Is evolution to blame?

'Nothing in Biology Makes Sense Except in the Light of Evolution'. We shine this light on obesity and see what it reveals.

We must first journey back to our 'environment of evolutionary adaptiveness'. This is just a technical term for the time in our evolutionary past where we spent the most time evolving. Basically - this is the environment we were most adapted to. In fact, it still is - for us Homo Sapiens have changed very little physically since we were chasing woolly mammoths.

If we examine this environment, we see that activity levels were high and caloric intake was low. We moved a lot and ate little. Or bodies adapted to this. Fast forward to present day, and we have bodies adapted to movement and starvation in an environment offering us the opposite - low activity levels and high caloric intake.

For those who would like to read exactly the same thing with more syllables, Bernard Swynghedauw tells us that 'Evolutionary, or Darwinian, medicine takes the view that contemporary diseases result from incompatibility between the conditions under which the evolutionary pressure had modified our genetic endowment and the lifestyle and dietary habits in which we are currently living, including the enhanced lifespan, the changes in dietary habits and the lack of physical activity.'

Not only are we moving less and eating more, but the 'eating more' is a case of too much of a good thing. For our distant ancestors it was an advantage to eat high levels of fat, sugar and salt. These food sources were scarce, and were/are vital to our survival. It was a survival advantage to like the taste of (and thus eat) these foods.

Jump forward 50,000 years and we still have this sweet tooth, but the fat and sugar are now plentiful. It really is too much of a good thing. Not only are we fighting our cravings, but thousands of years of evolution. Physical inactivity is an abnormal event for a genome programmed to expect physical activity.

And so, comes a cascade of chronic conditions, obesity, type two diabetes and hyperlipidemia.

With knowledge though, we have power; the power to modify lifestyle and overcome our modern day health damaging evolutionary urges.

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Dan Williams

Dan Williams is the Founder and Director of Range of Motion. He is an Accredited Exercise Physiologist and Exercise Scientist with a Bachelor of Science and a Bachelor of Exercise Rehabilitation Science. Dan is a CrossFit Coach (at CF Games Level) and four time CrossFit Regionals Athlete.