Recent WHO findings on increasing obesity rates throughout the world1 should come as no surprise. It’s been known for some time that overweight and obesity, at the population level, increases proportionally with economic development – and the world as a whole has been though its fastest rate of development in human history in the last 30 years.

How are obesity and development linked? Even an economic illiterate knows that the main factor behind development is consumption. Synonyms to ‘consume’ in Roget’s Thesaurus include: ‘eat’, ‘drink,’ ‘devour’, ‘munch through’, ‘chomp through’, ‘guzzle’.

So with the world on a development binge (and rightly so for those poorer countries to catch up), increasing weight, with increased outliers of obesity, would seem to be a natural progression.

“Another way to look at it is whether there is an underlying factor associated with obesity and the determinants of obesity that could, independently, cause chronic disease.”

 

The first question to ask about this is whether it matters. True, obesity has been linked with chronic diseases from respiratory problems to heart disease. But around 1 in 3 obese have no health risks, and around 1 in 4 lean people have all the risks expected of the obese.

And while this may be coincidental, the association between chronic disease and obesity determinants is such as to question whether it is obesity, or the things that cause obesity (poor diet, inactivity, stress, etc), rather than obesity per se, that has led to the dramatic rise in chronic diseases.

This is a difficult topic to study as it would involve ‘clamping’ obesity at a certain level while increasing food intake and/or physical inactivity, which typically cause increases in body weight.

Another way to look at it is whether there is an underlying factor associated with obesity and the determinants of obesity that could, independently, cause chronic disease.  In the past two decades a form of low grade, systemic and chronic inflammation (‘metaflammation’) has been shown to fill this role.

Metaflammation occurs with just about any determinant of obesity – high energy/fat/sugar, inactivity, too much sitting, poor sleep, depression, and even less obvious factors such as hunger inducing Endocrine Disrupting Chemicals (EDCs) in the environment.

 

Figure 1

Figure 1: The relationship between per capita Gross Domestic Product and obesity in different countries.

 

Could it be then that our obsession with the aesthetics of obesity has driven our desire to attack this while taking the focus off these determinants – and not just the proximal determinants like food, inactivity etc., the but ‘cause of the cause’ and the ‘cause of the cause of the cause’ like stress, peer pressure and even social and economic conditions?

A second question is whether it is economic development per se, or the type and phases of development, that lead to increases in obesity (and the factors discussed above that cause this), rather than development as a whole.

A sobering point here is that, contrary to the WHO view that no country in the world has impacted the obesity epidemic, some have  – if just for a while. Cuba for example, after the Russians left in 1990, had a big drop in obesity and related chronic diseases over the following decade, before returning to the obesity (and economic development) path in the mid 2000s.

Nauru, the small Pacific island blessed with superphosphate stores, also had significant reductions in obesity and diabetes with the reductions in the national wealth that accompanied the depletion of superphosphate in the 1990s.

So it seems that economic factors not only play a part in making us fat, but in thinning us out when things go lean. But this hasn’t happened in most countries since the depression (short-term downturns excluded).

What of those developed countries with similar levels of wealth? Do they all have similar levels of obesity?

It appears not, according to our own studies.2 As shown in the graph here, there are six English speaking countries at the top of the wealth scale that seem to exceed obesity levels of several other countries of similar wealth, that coincidentally, are not English speaking.

An excitable epidemiologist might jump to ascribe obesity to speaking English! But researchers have found that the type of market system driving development might be more relevant. The six countries with highest obesity rates have all been defined as ‘market liberal’, or ‘hard’ capitalist economies, where those with lower rates (mainly in Northern Europe and Japan), have tighter regulation on market status.

Why this happens is still in the realm of hypothesis. However, some researchers suggest greater inequality in the former group of countries leads to a lack of trust, which in turn leads to increased obesity as a result of greater striving for equality and less attention to health.

It’s a long bow to draw – that obesity is not a problem, but the things that cause it may be, and that these are greater in less equal societies. However it could have implications where Governments have little interest in social equality.


References:
1. Ng M et al. Lancet online, May 29,2014.
2. Egger G, et al.  Economics and Human Biology 2012;10(2):147-153.

This column first appeared in Medical Observer.