Wednesday, March 29, 2006

The Obesity Epidemic: Evidence and Hypotheses

by Edward Hugh

In an epoch of ever rising expectations about the increasing longevity of our lifespan what could be more appropriate than a hard look at one of the more controversial weak spots on an otherwise more optimistic horizon (I speak here obviously of the developed world, since I natural haven't forgotten the importance of HIV/AIDS and other problems like malaria which continue to dominate the agenda elsewhere). But the issue of obesity is an interesting one. Normally lifestyle and educational questions have tended to re-inforce our extended life expectations, could growing obesity represent the first serious counter tendency?

Well, here are the two papers on the agenda for tomorrow morning's session for which a summary has been posted online:

The global perspective: an increasing rate of change in obesity and key determinantsBarry M Popkin, CPC, University of North Carolina

Global energy imbalance and related obesity levels are rapidly increasing. The world is rapidly shifting from a dietary period in which the higher-income countries were dominated by patterns of degenerative diseases (while the lower and middle world were dominated by receding famine) to one in which the world is increasingly being dominated by degenerative diseases. This ppresentation documents the high levels of overweight and obesity found across higher- and lower-income countries, and the global shift of this burden toward the poor, as well as toward urban and rural populations. Among the interesting shifts examined are the differential trends in child and adult obesity and burden of obesity across the world.

Unequally Obese: Individual- and Area-Level Associations with Income Virginia W. Chang, MD, PhD; University of Pennsylvania

Although obesity is frequently associated with poverty, recent increases in obesity may not occur disproportionately among the poor. Furthermore, the relationship between income and weight status may be changing with time. We use nationally representative data from the National Health and Nutrition Examination Surveys (1971-2002) to examine (1) income differentials in body mass index [BMI: weight (kg) / height (m2)] and (2) change over time in the prevalence of obesity (BMI ≥30) at different levels of income. Over three decades, obesity has increased at all levels of income. Moreover, it is typically not the poor who have experienced the largest gains.

1 comment:

S.M. Stirling said...

Obesity is the result of a meeting of modern conditions and ancient genetic imperatives.

We're programmed to like fatty and sweet foods and to avoid unnecessary physical exertion.

Both these are positive survival traits in the environments in which we evolved.

Accordingly, there's really not much that can be done about them until the researchers come up with the "magic pill".

The problem will simply get worse until then, as more and more of the human race has a 1st-world lifestyle available -- witness the outbreak of obesity problems in places like South Korea.

Preaching the virtues of tofu and the Stepperciser won't do much.