The complexity of obesity

A moderately long read by David Berreby in Aeon magazine looks at a gaggle of theories about the causes and consequences of the worldwide epidemic of obesity: “The obesity era”. What got me to click over:

Consider, for example, this troublesome fact, reported in 2010 by the biostatistician David B Allison and his co-authors at the University of Alabama in Birmingham: over the past 20 years or more, as the American people were getting fatter, so were Americas marmosets. As were laboratory macaques, chimpanzees, vervet monkeys and mice, as well as domestic dogs, domestic cats, and domestic and feral rats from both rural and urban areas. In fact, the researchers examined records on those eight species and found that average weight for every one had increased. The marmosets gained an average of nine per cent per decade. Lab mice gained about 11 per cent per decade. Chimps, for some reason, are doing especially badly: their average body weight had risen 35 per cent per decade. Allison, who had been hearing about an unexplained rise in the average weight of lab animals, was nonetheless surprised by the consistency across so many species. Virtually in every population of animals we looked at, that met our criteria, there was the same upward trend, he told me.

The article spins a lot of stories, and spends some time with the ideas of Jonathan Wells, before its inevitable conclusion that we don’t yet know the complexity of obesity at the scale of populations. It is a case where anthropology can make some progress by examining obesity in different population contexts, both present and past.