If we’re all getting fat because or … well, whatever reason you like … why are lab animals on controlled diets getting fatter too?
Moral panic about the depravity of the heavy has seeped into many aspects of life …
… It is undoubtedly true that societies are spending vast amounts of time and money on this idea. It is also true that the masters of the universe in business and government seem attracted to it … What we don’t know is whether the theory is actually correct.
… Many researchers believe that personal gluttony and laziness cannot be the entire explanation for humanity’s global weight gain. … As Richard L Atkinson, Emeritus Professor of Medicine and Nutritional Sciences at the University of Wisconsin and editor of the International Journal of Obesity, put it in 2005: ‘The previous belief of many lay people and health professionals that obesity is simply the result of a lack of willpower and an inability to discipline eating habits is no longer defensible.’
Now, about those animals.
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 America’s marmosets. As were laboratory macaques, chimpanzees, vervet monkeys and mice…
… In fact, lab animals’ lives are so precisely watched and measured that the researchers can rule out accidental human influence: records show those creatures gained weight over decades without any significant change in their diet or activities.
Ah well, our diets are just a little too rich, right?
Such a global hidden factor (or factors) might help to explain why most people gain weight gradually … This slow increase in fat stores would suggest that they are eating only a tiny bit more each month than they use in fuel. But if that were so, as Jonathan C K Wells, professor of child nutrition at University College London, has pointed out, it would be easy to lose weight.
Well then what is the cause? No one is quite sure: too much light? heating and cooling that are too even? chemicals in our food? quasi-Marxist capitalism blaming? infection?
One weak point in the article: nowhere is the uncomfortable fact that heavy people live longer ever mentioned.
FWIW: This is a fair time to note that I am in my 7th year following Seth Roberts Shangri-La diet. I am still below my peak weight, and not having any trouble at all staying there (I exercise, but not much). Shangri-La is all about the thermodynamic explanation (a calorie is a calorie) being totally wrong.
Read the whole David Berreby article, entitled “The Obesity Era” in Aeon.