The contemporary developed world obesity epidemic has always struck me as being too widespread and occurring too fast to be due simply to a lack of self-discipline by lots of individuals.   Current medical advice is for individuals to eat less and exercise more, advice given despite the experimental evidence showing that increasing exercise actually may increase weight (on average), rather than reducing it.    And advice given despite the fact – known for at least 150 years, since the work of Claude Bertrand – that our bodies are complex adaptive systems, whose properties do not conform to simple linear models; for example, eating less may lead the body to retain more of the nutrients of the food ingested, because of a body-weight set-point effect, and thus not lead to much weight loss at all.   We already have evidence that appetite may have  genetic determinants.  Now, it seems that the obesity epidemic may have environmental or social causes, since as well as humans in the developed world putting on weight, so too have animals.  The animal species studied include not only pets and zoo animals (whose diets may have been influenced directly by human feeding), but also wild animals living near humans.

And schizophrenia, which once was blamed on poor parenting by the mothers of patients, and later on the patient’s genes (and who, Mothers, gave them those?), may in fact be caused by a virus – a retrovirus, present in our and our ancestors’ DNA for some 60 million years.  It turns out this is the same retrovirus that is believed by some scientists to cause Multiple Sclerosis.  A virus as cause could explain why there is a persistent, and statistically significant, effect on the incidence of schizophrenia arising from the season of birth of the patient.  Neither genes nor a mother’s parenting style would be expected to be influenced by the season of birth, but virus lifecycles, activations, durations and diffusions, certainly are.

The standard line initially of the medical panjandrums on RSI was that this medical condition only seemed to affect office workers, and not others who worked a lot with their hands, such as musicians.    The implication of such a statement was that the causes of RSI could not be some objective condition, outside of the patient, and so must be internal, either psychosomatic or actually knowingly invented.  Yet, musicians for at least a couple of centuries have been suffering from RSI (or closely-related conditions), as anyone who asked them would know.

When the medical profession is ready to apologize to us all for wrongly accusing us of moral failings, weakness of will, or malfeasance, I’ll be here ready and waiting.  I’m not, however, holding my breath.

Now, science tells us that appetite – and hence obesity – may also be a function of one’s genes, as this article in tomorrow’s SMH reports.