Posts Tagged ‘Food cravings’

Craving for junk food is proof that natural selection is obsolete

December 4, 2015
christmas dinner (guardian)

christmas dinner (guardian)

It is that time of the year. There are luscious smells of baking and roasting and frying that assail my poor brain. Almost everything that makes my mouth water is bad for me. I have just about recovered from the frustrations of abstinence from Diwali sweets and Christmas is now already upon us. I have just been soaking the dried fruits in my second best brandy and they can absorb no more. Dark, bitter chocolate and marzipan and glazed cherries are coming out of their hiding places in the larder (and they are hidden to keep me from them). Now I feel schizophrenic. My unconscious brain is delighting in all the good things to come but my conscious, rational brain is just making a list of eating pleasures that will be heavily curtailed or may not even be.

image londonbeep.com

image londonbeep.com

And that got me to wondering why natural selection and evolution could be so horribly, ineffective. How come, I do not crave what is healthy and good for me? If evolution worked properly and worked towards my survival, then surely my brain would crave salads and raw vegetables and fruits and maybe some nuts, but not honey-glazed ham and choux pastry dipped in dark chocolate and filled with cream. Or brandy butter and Christmas cake saturated with booze. Why do I find roast potatoes so much more enticing than plain boiled potatoes (except of course if they were new potatoes and covered in herb butter and melted cheddar)?

My tentative theory is that in the last 2000 years humans have become experts at creating their own, favourable environmental bubbles in which they live. Our bubbles include the production of our food. We live in the Arctic or at the equator and maintain a tropical climate around ourselves throughout the year. Refined sugar and processed meat and hot house vegetables are things that natural selection was not intended to cope with. I read that we crave certain foods to balance the serotonin that our brains desire to maintain a “proper” balance – whatever that might be. Carbohydrates provide serotonin which dispels stress and anxiety. Fats and sugar together produce calm and even euphoria. Before we controlled the production and processing of our foods we only had access to natural sugars through fruits and some vegetables. Meats provided fats. Quantities imbibed were necessarily limited, for sources were not as readily available until after agriculture and animal domestication were established (say from 20,000 to 10,000 years ago for the transition). And there has been another massive step change in the availability of these foods and in their affordability in the last 100 years.

The rate of change with which humans have established the environmental bubbles we create, and in the foods available to us, has been much too fast for natural selection to cope with. Moreover, even though what is bad for us may eventually kill us, medical advances mean that even the “unfit” lovers of bad foods live long enough to reproduce and pass on their genes. Natural selection no longer has a role to play. It has been bypassed and has become irrelevant. Medical care now negates all the deselection of “unfit” individuals that natural selection once eliminated.

I see evolution actually as the result of the individuals who get deselected rather than a proactive selection of those individuals who are just good enough to survive. (It has never been about the survival of the fittest – but only of the selection – by default – of those just fit enough to survive). Hence my conclusion that my cravings for unhealthy foods are the fault of an ineffective and obsolete natural selection.

So as I struggle with (and sometimes give in to) temptations for the next month, I will console myself by blaming the imperfect, lethargic and ineffective natural selection which has failed me.


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