The TechnoPhysio Evolution

June 8th, 2011 No comments »

Book Review:    The Technophysio Evolution    

The Changing Body, Health, Nutrition, and Human Development in the Western World since 1700

 by Roderick Floud, Robert W. Fogel, Bernard Harris and Sok Chul Hong, (Cambridge Press, 2011)

The authors are distinguished economists (Fogel has a Nobel Prize in Economics). With dizzying detail, it traces the changes in the human body over the last 300 years in Britain, France and the United States. During this period, humans have become much taller and heavier than ever before. The book charts the “technophysio evolution,” a complex interplay between increasing technological changes and improved standards of living, resulting in improved nutrition. The improved nutrition is passed from mother to child to child with improvements in height and weight in successive generations. This is not a straight line but the trends are unmistakable – improved mortality with tall and heavier adults.

The Technophysio Evolution hypothesis has three elements:

  1. The nutritional status of a generation – shown by the size and shape of their bodies – determines how long that generation will live and how much work its members will be able to do.
  2. The work of a generation, measured both in hours, days, and weeks of work and in work intensity, when combined with the available technology, determines the output of that generation in terms of goods and services.
  3. The output of a generation is partly determined by its inheritance from past generations; it also determines its standard of living and its distribution of income and wealth, together with the investment it makes in technology.
  4. The standard of living of a generation determines, through its fertility and distribution of income and wealth, the nutritional status of the next generation.
  5. And so on, ad infinitum.

In other words, increasing body weight is a by-product of advances in wealth and income, producing healthier, i.e. larger children, who, in turn, produce better nourished, i.e., larger,  children.

The “techno” part of this evolution include everything from American colonists moving from a wooden plow to an iron one; improvements in food production and distribution, refrigeration, canning, changes in water, sanitation and public health which reduced mortality from infectious diseases while improving nutrition for more and more people.

The “physio” part incorporates research on the fetal origins of adult disease and will support the attention to epigenetics as an important aspect in the development of obesity. This is not purely genetics or genetic determinism but the process of transition of improvements in nutrition to the health of the mother and her survival as well as to the survival of more children for longer periods of time. Epigenetic changes is coming into focus as a critical stages for the development of obesity and will certainly receive more attention in the future. Epigenetic changes in early life and future risk o… [Int J Obes (Lond). 2010] – PubMed result

Is there an end to the process or is there a natural limit to this growth? Well, we don’t really know but none appears so far. (It seems to me, at least, that evolution has not felt it necessary to provide unlimited height of the species since there does not appear any survival value to being taller. On the other hand, nature has felt that there was a distinct survival value to being able to store energy (read fat) on our bodies and there does not seem to be a particular limit to this.)

by permission, Cambridge University Press

 

Interestingly, the authors find that, for American white males ages 40-59, the increase in BMI from 1870 to 1980 is less closely related to food consumption than to reduction of contaminated environments and work hours. “Not only have working hours,” they write, “declined substantially throughout the twentieth century, but the type of work became more sedentary, and so required less energy.” However, “The recent large increase of BMI in 1980-2000 (6 percent) is highly connected to increased food intake during the period (22 percent). (At p. 336) Further, they note the average BMI of American white males has increased by 15.7% throughout the 20th Century, half during the last two decades of the twentieth century. “This means that American body size is rapidly moving toward overweight and obesity.This would seem compatible with a new finding from Tim Church and colleagues at the Pennington Biomedical Research Center that in the 1960’s about half of jobs in private industry required at least moderate physical activity. That figure is now less than 20%. Over the last 50 years, occupational daily energy expenditure decreased from by 142 calories in men and a similar amount in women.  Trends over 5 Decades in U.S. Occupation-Related P… [PLoS One. 2011] – PubMed result

What are the policy implications of this Technophysio Evolution?

First, increases in body size are a product of 300 years improvement in technology, productivity and standards of living. This evolution began long before television, fast food, vending machines, sugar-sweetened beverages and other would-be villans in the obesity epidemic.

Second, the very same nutritional improvements which led to larger bodies in Europe and the United States are being actively pursued in undernourished parts of developed nations and throughout the developing world. This indicates greater and greater levels of obesity in the developing world with obesity related diseases.

Third, epigenetics needs to receive more attention as a point of intervention in the development of obesity.

Fourth, simplistic views that blame individuals and proclaim that just cutting back food  or going to the gym will fix the obesity epidemic.  Strategies which just repeat the ELEM mantra (Eat Less Exercise More) have to be questioned if those strategies are likely to affect this profound historical trend.

A few years ago, Gina Kolata, in her book, Rethinking Thin (Farrar,Straus and Giroux, 2007)  discussed the views of some obesity researchers that we are looking at a new stage in the evolution of the species. This tome adds significant evidence that our obesity strategies need to be re-thought to take this 300 year trend into account.

December 30th, 2009 No comments »

December 29, 2009

Study disputes ‘healthy and obese’ fallacy  Study Debunks Notion of ‘Healthy Obese’ Man – BusinessWeek

December 29, 2009

Vivus announces plans to submit Qnexa for FDA approval Vivus says it asked FDA for marketing approval of its obesity drug candidate Qnexa — latimes.com

December 24, 2009

Arena Pharmaceuticals submits New Drug Application for lorcaserin to FDA. Arena Pharma seeks US FDA approval for obesity drug lorcaserin – International

December 11, 2009

New York Times feature on poor children getting obesity-inducing anti-psychotic medications on Medicaid Children on Medicaid Found More Likely to Get Antipsychotics – NYTimes.com

December 7, 2009 Lincoln University ends controversial BMI-graduation policy Lincoln Ends BMI Requirement – The Paper Trail (usnews.com)

December 4, 2009

America Samoa tops lists of world’s most obese countries Size matters: American Samoa tops ‘globesity’ scale

December,  2009

Diabetes cases and costs expected to double in next 25 years. Projecting the future diabetes population size and… [Diabetes Care. 2009] – PubMed result

November 27, 2009

University takes flak for singeling out obese students A University Takes Aim at Obesity – The Choice Blog – NYTimes.com

November 24, 2009

CDC releases county obesity rates.  Obesity and Overweight for Professionals: Data and Statistics: U.S. Obesity Trends | DNPAO | CDC

See interesting commentary from Richard Florida of the Atlantic The Geography of Obesity – Richard Florida

November 23, 2009

It seems obesity drugs can’t catch a break. Now there is news that Abbott’s Meridia is being watched by the Food and Drug Administration for increased cardiovascular deaths. It was widely known to increase blood pressure. New Meridia SCOUT Trial has Major Implications for Obesity Drug Development – GLG News This means that for companies bringing new products to the FDA for approval will find even greater scrunity.

November 17, 2009

USA Reports rising costs of obesity epidemic Rising obesity will cost U.S. health care $344 billion a year – USATODAY.com

ACOG issues guidelines on bariatric surgery and pregnancy Bariatric surgery and pregnancy.

Yale course by Kelly Brownell on psychology, biology and politics of food available on line for free The Psychology, Biology and Politics of Food — Open Yale Courses

ASMBS offers on line CEU course on bariatric surgery American Society for Metabolic and Bariatric Surgery

America’s Health Rankings sets obesity state by state projections to 2013 Projected Prevalence of Obesity

November 11, 2009

HHS issues report on health care reform and diabetes Preventing and Treating Diabetes: Health Insurance Reform and Diabetes in America

Dr. Sharma takes on lifestyle choice or chance? Dr. Sharma’s Obesity Notes » Blog Archive » Obesity: Lifestyle Choice or Lifestyle Chance?

November 9, 2009

Downey Obesity Report joins call for health reform to address morbid obesity 15 Million Americans at Greatest Risk of Disease/Death Have Been Left Out of Health Reform Debate – SmartBrief

Study confirms link between swine flu and extra weight

November 5, 2009

California reports important link between obesity and swine flu

Obesity causes over 100,00 new cases of cancer Obesity linked to specific cancers – USATODAY.com

Obesity causing problems in military recruiting Obesity, poor education big obstacles to military recruiting – washingtonpost.com

November 4, 2009

California swine flu report point to obesity risk. In a study published today in JAMA, researchers looked at deaths and hospitalizations due to H1N1 flu in California. They state, “A large proportion of our adult cases had other comorbidities that are not established risk factors for severe influenza, including hypertension and obesity. Of adults with BMI data available, more than half were obese and one-quarter were morbidly obese…Almost one-third ob obese cases did not have other established risk factors for severe influenza, although 27% had other comorbidities (eg, hypertension) Others have reported this novel association in pandemic 2009 influenza A (H1N1) infection; diabetes and obesity were the most frequently identified underlying conditions in fatal cases older than 20 years worldwide, and anecdotal observations of high prevalence of obesity in severe and fatal cases have been reported from Chile, Manitoba and Mexico. Factors associated with death or hospitalization d… [JAMA. 2009] – PubMed result

New evidence from mouse studies on genetic transmission Do Fat Parents Have Taller Babies? Mice study indicates surprising relationships between food, height, and families. – The Human Condition Blog – Newsweek.com

October 28, 2009

DPP 10 year results A Decade Later, Lifestyle Changes or Metformin Still Lower Type 2 Diabetes Risk, October 29, 2009 News Release – National Institutes of Health (NIH)  10-year follow-up of diabetes incidence and weight… [Lancet. 2009] – PubMed result

Genetic Basis of Obesity

September 26th, 2009 No comments »

Often one hears it stated that obesity is not a genetic disease. If by that the speaker is saying that obesity is probably not due to a single genetic change they are not quite right. There are some rare forms of obesity which are due to a single gene change. Genetic obesity syndromes. [Front Horm Res. 2008] – PubMed Result; Genetic and hereditary aspects of childhood obesit…[Best Pract Res Clin Endocrinol Metab. 2005] – PubMed Result But if they mean a single genetic change cannot account for a worldwide epidemic of obesity occurring over the last 30 years they are probably right. If the speaker means it is unlikely that there will be a treatment for obesity based on gene therapy, they are probably correct. (Although who can predict the future?) However, they miss the point if they do not understand that for millions of years of evolution, the species we call humans have favored genes which maximize its chances for survival and reproduction. So our taste preferences, our physical activity preferences and the like are passed on in the genome and our part of our inheritance. The problem is that for centuries we humans lived in an environment which was totally different than the one we live in now. The disconnect is that our bodies have not yet adapted to this new world where tasty, nutritious food is readily available and where most of us do not have to expend anything other than a minimal effort to obtain it, survive and flourish. Anything policy-makers or parents want to do about obesity must be understood in the context of the powerful force evolution has been in designing how humans acquire, store and use energy from food.

According the CDC:

  1. Biological relatives tend to resemble each other in many ways, including body weight. Individuals with a family history of obesity may be predisposed to gain weight.
  2. Different responses to the food environment are largely due to genetic variation between individuals.
  3. Fat stores are regulated over long periods of time by complex systems that involve input and feedback from fat tissue, the brain and endocrine glands like the pancreas and the thyroid. http://www.cdc.gov/genomics/training/perspectives/files/obesknow.htm,
  4. The tendencies to overeat and be sedentary, the diminished ability to use dietary fat as fuel and enlarged, easily stimulated capacity to store body fat are all genetically influenced. The variation in how individuals respond to the food rich environment and the differences in acquiring obesity related comorbid conditions are also genetically determined. http://www.cdc.gov/Features/Obesity/

Since 1997, published studies have found that variation in BMI is largely due to heritable genetic differences, with estimates ranging from 55% to 85%. A 2008 study found that 77% of the adiposity in preadolescent children born since the start of the obesity epidemic was due to genetic inheritance compared to 10% for the environment. Evidence for a strong genetic influence on childho…[Am J Clin Nutr. 2008] – PubMed Result

A fast rate of eating appears to be heritable. Eating rate is a heritable phenotype related to we…[Am J Clin Nutr. 2008] – PubMed Result Differences in responding to the obesogenic environment may also be heritable Genetic influence on appetite in children. [Int J Obes (Lond). 2008] – PubMed Result and Appetite is a Heritable Phenotype Associated with …[Ann Behav Med. 2009] – PubMed Result. The FTO gene may be involved. The FTO gene and measured food intake in children. [Int J Obes (Lond). 2009] – PubMed Result and Increasing heritability of BMI and stronger associ…[Obesity (Silver Spring). 2008] – PubMed Result Parental leanness appears to provide strong protection against the development of obesity in children. Development of overweight in children in relation …[Obesity (Silver Spring). 2009] – PubMed Result

There is an interesting scientific debate about what is called the “thrifty gene” hypothesis about how a genetic preference for storing extra energy on our bodies might have developed. Thrifty genes for obesity, an attractive but flawe…[Int J Obes (Lond). 2008] – PubMed Result and The clinical biochemistry of obesity. [Clin Biochem Rev. 2004] – PubMed Result. Some think that childhood obesity is increasing due to ‘associative mating’ by overweight parents who pass on their genetic disposition to obesity to their children. Childhood obesity: are genetic differences involve…[Am J Clin Nutr. 2009] – PubMed Result

The evidence for the genetic basis of obesity, in addition to environmental changes is quite strong. See Implications of gene-behavior interactions: preven…[Obesity (Silver Spring). 2008] – PubMed Result; Genome-wide association scan shows genetic variant…[PLoS Genet. 2007] – PubMed Result and The genetics of obesity. [Metabolism. 1995] – PubMed Result

The environment is thought to be responsible for variations between populations but genetics is responsible for the variations within a given population. Obesity – Missing Heritability and GWAS Utility and Genetic and environmental factors in relative body…[Behav Genet. 1997] – PubMed Result. Genetics may account for many cases of morbid obesityFamilial aggregation of morbid obesity. [Obes Res. 1993] – PubMed Result.

Genetics may play an important role in determining who can benefit from different types of intervention. Implications of gene-behavior interactions: preven…[Obesity (Silver Spring). 2008] – PubMed Result or who is more likely to be affected by obesity Ethnic variability in adiposity and cardiovascular…[Int J Epidemiol. 2009] – PubMed Result. Or experience a comorbid condition like Type 2 diabetes Mechanisms of disease: genetic insights into the e…[Nat Clin Pract Endocrinol Metab. 2008] – PubMed Result

The FTO gene is currently under active research interest for providing a link to how obesity related conditions might arise and how patients can benefit from this knowledge. FTO: the first gene contributing to common forms o…[Obes Rev. 2008] – PubMed Result Genome-wide association scan shows genetic variant…[PLoS Genet. 2007] – PubMed Result

The FTO gene may explain different responses to exercise. FTO Genotype Is Associated With Exercise Training-…[Obesity (Silver Spring). 2009] – PubMed Result .Physical activity and the association of common FT…[Arch Intern Med. 2008] – PubMed Result

A factor in the resistance to describe obesity as a genetic disease may be in the assumption that the human genome does not change rapidly whereas the increase globally in the rates of obesity have occurred in the last 40-50 years. However, evolutionary biologists are debating the speed of genetic change. In “Catching Fire, How Cooking Made us Human” (Basic Books, New York, 2009) Richard Wrangham, the Ruth Moore Professor of Biological Anthropology at Harvard University writes,

A long delay between the adoption of a major new diet and resulting changes in anatomy is also unlikely. Studies of Galapagos finches by Peter and Rosemary Grant showed that during a year when finches experiences an intense food shortage caused by an extended drought, the birds that were best able to eat large and hard seeds – those birds with the largest beaks- survived best. The selection pressure against small-beaked birds was so intense that only 15 percent of birds survived and the species as a whole developed measurably larger beaks within a year. Correlations in beak size between parents and offspring showed that the changes were inherited. Beak size fell again after the food supply returned to normal, but it took about fifteen years for the genetic changes the drought had imposed to reverse. The Grants’ finches show that anatomy can evolve very quickly in response to dietary changes…Other data show that if an ecological change is permanent, the species also changes permanently, and again the transition is fast…The adaptive changes brought on by the adoption of cooking would surely have been rapid. (p. 93-94, emphasis added.) (See Book Reviews)