Why obesity isn’t a disease – it’s just the changing shape of humanity
A fascinating new thesis argues that biologically we are unlike any generation that has gone before. James Marriott learns that he belongs to the ‘‘consumer phenotype’’.
Species are shaped by their genes and by their environments. Modern humans, Edwin Gale argues in The Species that Changed Itself, are in the strange position of being shaped by an environment they created.
This man-made environment – characterised by affluence, abundance and education – has given rise to a new kind of human, biologically distinct from previous instalments of the species.
The term Gale uses is ‘‘the consumer phenotype’’ (the word phenotype refers to an individual’s observable biological traits, which are the product of genetic and environmental factors).
Modern humans are taller, fatter, longer-lived, more empathetic and (possibly) more intelligent than their predecessors.
I have tried to lay out the book’s argument clearly in the first paragraph of this review because its author is a compulsive digresser and progress is not always straightforward or logical.
Like all digressers Gale, emeritus professor of medicine at Bristol University, is betrayed by his index.
A glance at ‘‘M’’ yields conclusive proof of a distractible mind: ‘‘Montaigne, Michel de’’, ‘‘Montgomery, Tim’’, ‘‘Mouse, Mickey’’, ‘‘Mayhew, Henry’’, ‘‘Mao Tse Tung’’, ‘‘Milgram experiments’’, ‘‘models and supermodels’’, ‘‘molecular biology’’, ‘‘Much Hadham, Hertfordshire’’, ‘‘menstruation’’, ‘‘metaphor’’ and ‘‘military recruitment, Boer War’’ ... You get the idea.
Anyway, Gale identifies three dominant human phenotypes in history. The first is the ‘‘paleolithic phenotype’’, which refers to our hunter-gatherer ancestors. These humans were tall and long-legged with as little body fat as modern marathon runners.
They were fit (some were probably capable of running an antelope to exhaustion) and had excellent dentition (no grains to get stuck between teeth and no sugar).
They did not suffer from epidemic diseases (which can’t spread among scattered tribes) and diabetes and vascular disease were almost unknown.
As they aged they did not gain weight and their blood pressure did not rise.
Next in historical order is the ‘‘agrarian phenotype’’. The first agricultural revolution, which took place about 10,000 years ago, made human life miserable.
Settled existence and a less varied diet meant this next batch of humans were smaller, shorterlived, anaemic and exposed to the diseases that jump to humans from livestock and pests that gather wherever humans settle.
A life of hoeing and grinding corn meant women of the ‘‘agrarian phenotype’’ typically had upper-arm bone density greater than members of the Cambridge women’s rowing team.
To proceed the reader must follow Gale’s argument through dense thickets of anecdote. And sometimes (as you hack your way through discussions on the molecular elegance of the HaberBosch process, the difference between Ottoman and Chinese eunuchs, the bride-fattening customs of the Annang tribe in Nigeria, the dangers of anabolic steroids, and Edward Gibbon’s fondness for sweet wine) you wonder if you’ve lost your way entirely. But fear not: you will always break into a clearing of lucid argument.
The anecdotes, it should be said, are high-quality. I found I was glad to know that a nubile Annang maiden is sent to the ‘‘fattening room’’ for several months before she is paraded before her village in a state of obesity, entirely nude apart from decorations of ‘‘beads, feathers and bells’’.
The typical Gale anecdote is characterised by flourishes of incongruous pedantry.
Otto von Bismarck, Gale informs his readers, had a BMI of 30.9 (obese) while the 18-yearold Lord Byron had one of 29 (very overweight). Byron lost almost five
stone by going on a diet that required him to soak all his food in vinegar.
To return, as Gale frequently doesn’t, to the book’s argument: the discovery of industrial-scale techniques for nitrogen fixation in the 19th century allowed the development of modern fertiliser production and the dawn of a new age of hyper-abundant food, the key development that underpins Gale’s consumer phenotype.
In previous centuries artists such as Pieter Aertsen and
Nathaniel Bacon had conjured up fantastical visions of agricultural cornucopias. The cover of the book is resplendent with Bruegel the Elder’s peasant dream of plenty, The Land of Cockaigne. Today these are simply the sights greeting anyone walking through the sliding doors of a supermarket.
Obesity is the most visually impressive marker of the consumer phenotype. But obesity, Gale argues, is not a disease, it is simply an aspect of the changing human phenotype.
He has little truck with alarmist talk of an ‘‘obesity epidemic’’ of equivalent seriousness to the climate crisis. It’s more complicated than that: ‘‘the life expectancy of the overweight is increasing’’ and ‘‘the obesity epidemic has coincided with a surprising and massive decline in death from coronary heart disease’’. Precisely why this is so is unclear (more sophisticated medical intervention and a decline in smoking are probably involved).
Overall, humans are ‘‘more fat adapted than in the past’’ and just as 60 is the new 50 in terms of age, ‘‘80kg seems to have become the ‘new 70’ in terms of weight’’.
He points out that fatphobia reinforces inequality. Wealth is highly correlated with lower BMI. Discriminating against the fat often means discriminating against the poor: ‘‘social exclusion has become associated with obesity: the rich get richer, and the poor get fatter’’.
Similarly, Gale argues, our society tends to pathologise old age rather than accepting that the difficulties of extreme long life (which modern lives are, in historical context) are simply another aspect of the new phenotype. He points out that ‘‘the range
of ‘normal’ for weight, blood pressure and so forth is defined as the range in healthy young adults ... any upward shift in older people is considered unhealthy’’.
We should accept that pills are ‘‘now a routine feature of later life’’ and ‘‘there is nothing intrinsically wrong in this’’; after all, ‘‘pharmaceuticals are no more unnatural than spectacles’’.
‘‘It takes a society that equates youth with health to label [older people] as sick.’’ I can’t decide whether this is casuistry or common sense.
Another mark of the consumer phenotype is adolescence. Thanks to healthier mothers and affluent childhoods ‘‘children now enter puberty up to four years earlier’’ than they once did.
‘‘Data from Oslo show that the average age at first menstruation fell from 16.5 to 12.5 years between the 19th and 20th centuries’’ (presumably not right between).
‘‘[Emperor] Augustus had his first shave when he was 23, and the shaving ceremony that welcomed Roman citizens to manhood generally took place at between 21 and 23 years.’’
On which note, Gale is unable to restrain himself from explaining that ‘‘earlier puberty became a headache for choir masters’’. Bach had male sopranos as old as 19 in his choir at Leipzig. A modern conductor has probably lost all of his by the time they turn 14.
This in turn reminds Gale that the reason ‘‘Gregorian chant was pitched in the tenor range’’ was that people in the past were smaller and had feebler vocal cords. The bass voice arrived only as society grew more affluent and in the 15th century Italian courts had to import bass singers from super-abundant Belgium.
Gale then invites his readers to baroque new heights of digression as he asks us to meditate upon the lost beauty of the voices of 18th-century Italian castrati.
You should also buy the book if you wish to discover the connection between literacy and empathy, the reason male faces have become more feminine over the recent centuries, or to know why American universities have archives packed with photographs of nude students including ‘‘pictures of prominent Americans ranging from John F Kennedy to Hillary Rodham Clinton’’.
Finally I wish to say that I fear I have been unfairly joshing towards Gale.
We condemn in others the faults we are most conscious of in ourselves. I am a brother anecdotalist and I recognise his weakness as mine.
His book is humane and fascinating and it has a compelling argument. You will not be bored reading it and if you can’t be bothered to read it cover to cover you can simply open it at random to find a good story for your next dinner party.
A life of hoeing and grinding corn meant women of the ‘‘agrarian phenotype’’ typically had upper-arm bone density greater than members of the Cambridge women’s rowing team.