Air Pollutants Linked to Childhood Obesity

May 19th, 2012 No comments »

Exposure to air pollution while in the womb may contribute to childhood obesity, according to a study just published in the American Journal of Epidemiology by Andrew Rundle. Polycyclic aromatic hydrocarbons (PAHs) are common air pollutants caused by burning coal, oil, gas and cigarette smoke.

The study followed 700 pregnant women in New York City who were African-American or Dominican and lived in relatively poor areas of the city. Pregnant women with high exposures had children who were 1.8 times more likely to be obese at 5 years of age and 2.3 times more likely to be obese at 7 years than children with lower levels of exposure. PubMed: Air pollutants and Obesity

Could obesity be contributing to rise in Autism?

May 19th, 2012 No comments »

Obesity is known to contribute to birth defects. Now comes a new study linking obesity, type 2 diabetes and hypertension to autism spectrum disorders and developmental delays. More

Study Links Autism to Obesity, Diabetes

May 19th, 2012 No comments »

The increasing prevalence of autism spectrum disorders (ASD) has been both controversial and concerning to parents and health professionals. Could obesity and type 2 diabetes be responsible for some of the increase?

In a  paper in the May 2012 Pediatrics, researchers from the CHARGE (Childhood Autism Risks from Genetics and Environment) study in California, looked to see if metabolic conditions, specifically type 2 diabetes, hypertension and obesity, in mothers during pregnancy were associated with ASD or developmental delays (DD) in offspring. The study involved 517 children with ASD, 172 DD, and 315 controls. The researchers found that all metabolic conditions were more prevalent among mothers with affected children. Collectively, these conditions were associated with a higher likelihood of risk of ASD and DD relative to controls (odds ratio 1.61 and 1.10, respectively).

The authors state, “In a diabetic and possibly prediabetic pregnancy, poorly regulated maternal glucose can result in adverse fetal development. “  Concluding, they point out, “The prevalence of obesity and diabetes among US women of childbearing age is 34% and 8.7% respectively. Our findings raise concerns that these maternal conditions may be associated with neurodevelopmental problems in children and therefore could have serious public health implications. PubMed: Maternal Metabolic Conditions

Are Persons with Obesity Different?

September 27th, 2011 No comments »

Are persons with obesity different? The question is fraught with implications. Much of obesity policy is premised on the assumption that persons with obesity are just like normal weight persons but with less self-control. The assumption is that education and awareness will overcome their lack of awareness and result in more self-control, just like normal weight persons. Of course, a genetic basis for obesity is counter to this assumption. How does this genetic pre-disposition express itself? Two recent studies may provide insights. In one, overweight persons show a higher capacity for storing fats but a lower capacity for ridding themselves of them, using the radioactive isotope carbon-14. Cell dysfunction linked to obesity and metabolic disorders | ScienceBlog.com

 In another study, the brains of persons with obesity were found to create a greater desire for high-calorie foods than normal-weight subjects which would explain why people who become overweight tend to remain overweight. Study: Obese people’s brains may crave high-calorie foods – USATODAY.com

U.K. Aims at Fetal Programming To Fight Obesity

July 4th, 2011 No comments »

The United Kingdom has launched the first trial of an effort to affect the intrauterine environment and thus the development of childhood obesity in the womb. The trial is sure to be controversial but it is certainly consistent with recent scientific findings. See Programming a Fetus for a Healthier Life – WSJ.com

More Disease and Death Ahead. It’s Going to Get Ugly

July 4th, 2011 No comments »

Editor:  This is a really important paper.

Forecasting the future effects of obesity has been a complicated business. One reason is that just measuring a current trend and then projecting it into the future (called the ‘two-dimensional model”) does not incorporate the changes occurring now to younger persons which will not become manifest until much further into the future.  Two examples are exposure by children to second-hand  tobacco smoke and childhood or adolescent obesity.  Underforecasting the effects of an epidemic like obesity can lead policy makers to pay insufficient attention or devote inadequate resources or direct those resources in unproductive ways. Unfortunately, it seems all of those poor outcomes are occurring.

So another method, the “three-dimensional” model has been developed to take future changes into effects. It is not a pretty picture.  The authors of a new paper in Health Affairs, Eric N Reiter, S. Jay Olshansky and Yang Yang, write, “We have shown that a reversal in US life expectancy rates is a distinct possibility in the long term, and a high probability in the short term for subgroups of the population most affected by obesity.” They note that childhood and adolescent obesity will predict the metabolic syndrome in many, as well as type 2 diabetes. After reviewing the evidence on the inter-generational inheritance process of transmission of obesity, they warn, “For example, fetal overnutrition has been shown to permanently increase appetite and shift preferences toward junk food among offspring, increasing the risk of obesity. Both human and animal studies indicate that maternal and paternal health behaviors – such as diet and smoking – affect the probability of obesity and related metabolic programming. In other words, a child’s metabolism and risk for certain diseases later in life can be “programmed” by conditions that existed during gestation. ..The implications of this body of science are profound: the high prevalence of obesity observed among younger people today is likely to be transmitted to future generations – regardless of the health behaviors of children yet to be born.” (Emphasis added.) So, this paper indicates we are underestimating the impact of childhood and adolescent obesity. See New Forecasting Methodology Indicates More Disease And Earlier Mortality Ahead For Today’s Younger Americans

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.

Inheritance Factors

September 26th, 2009 No comments »

Genes are not the only way characteristics may be passed from generation to generation. Researchers are actively pursuing what is called epigenetics. Epigenetics refers to changes in appearance, or phenotype, which is not due to changes in the DNA, which regulates genes and their expression.

Intrauterine Environment

The intrauterine environment (the womb) has been shown to affect the child’s disposition to obesity. Fetal origins of obesity. [Obes Res. 2003] – PubMed Result and Programming of body composition by early growth an…[Proc Nutr Soc. 2007] – PubMed Result Maternal and child obesity: the causal link. [Obstet Gynecol Clin North Am. 2009] – PubMed Result Gestational weight gain may predispose offspring to obesity and high blood pressure Associations of gestational weight gain with offsp…[Circulation. 2009] – PubMed Result and Gestational weight gain and risk of overweight in …[Am J Clin Nutr. 2008] – PubMed Result

Multiple factors are probably at work leading to an increased risk of developing obesity. Developmental origins of childhood overweight: pot…[Obesity (Silver Spring). 2008] – PubMed Result and Early determinants of overweight at 4.5 years in a…[Int J Obes (Lond). 2006] – PubMed Result

The question is to what extent the genes or the intrauterine environment influence the progression to adult obesity. The influence of birthweight and intrauterine envi…[Int J Obes Relat Metab Disord. 2003] – PubMed Result

One way in which the fetus might be affected in his or her development is by enhanced nutrition in the womb

Intrauterine changes are thought by some to contribute to the increase in obesity in India. Obesity epidemic in India: intrauterine origins? [Proc Nutr Soc. 2004] – PubMed Result

Maternal weight gain during pregnancy may affect the baby’s birth weight and long term risks Gestational weight gain and child adiposity at age…[Am J Obstet Gynecol. 2007] – PubMed Result

Detrimental influences in the womb, such as smoking Maternal smoking during pregnancy and child overwe…[Int J Obes (Lond). 2008] – PubMed Result, Association of maternal lifestyles including smoki…[Obesity (Silver Spring). 2007] – PubMed Result, Associations of maternal prenatal smoking with chi…[Obes Res. 2005] – PubMed Result, and famine The Dutch Famine of 1944-1945: a pathophysiologica…[Curr Opin Clin Nutr Metab Care. 2006] – PubMed Result or harmful chemicals Developmental exposure to endocrine disruptors and…[Reprod Toxicol. 2007 Apr-May] – PubMed Result and Role of nutrition and environmental endocrine disr…[Mol Cell Endocrinol. 2009] – PubMed Result

An unique, new study found that maternal weight loss from bariatric surgery may improve cardiometabolic  risks in infants which is sustained into adulthood.Effects of Maternal Surgical Weight Loss in Mother…[J Clin Endocrinol Metab. 2009] – PubMed Result

 

Early infancy

Weight status in the first 6 months of life and ob…[Pediatrics. 2009] – PubMed Result

Predictors of body size in infancy Predictors of body size in the first 2 y of life: …[Int J Obes Relat Metab Disord. 2004] – PubMed Result

Parental feeding styles

Children from obese parents were more likely to have a preference for fatty foods, lower liking for vegetables and a more overeating type eating style than children with lean parents as well as a greater preference for sedentary activities. Food and activity preferences in children of lean …[Int J Obes Relat Metab Disord. 2001] – PubMed Result The picture of the obese mother using food for non-nutritive purposes may be a myth but there obese mothers may exercise less control. Parental feeding style and the inter-generational …[Obes Res. 2002] – PubMed Result Infants of overweight/obese mothers have higher energy intake Relationship between maternal obesity and infant f…[Nutr J. 2005] – PubMed Result Infants born to overweight/obese mothers have lower resting metabolic rate, higher BMI Lower energy expenditures in infants from obese bi…[Nutr J. 2008] – PubMed Result

Breastfeeding

Breastfeeding has long been considered protective against the development of obesity Association between infant breastfeeding and overw…[JAMA. 2001] – PubMed Result

But not everyone is convinced.Critical review of the World Health Organization’s…[Obes Rev. 2008] – PubMed Result and Breastfeeding and the risk of childhood obesity. [Coll Antropol. 2007] – PubMed Result

How breastfeeding might be protective has not yet been determined. Mechanisms underlying the association between brea…[Int J Pediatr Obes. 2009] – PubMed Result

Overweight/obese mothers may be less likely to breastfeed their children than normal weight mothers. A systematic review of maternal obesity and breast…[BMC Pregnancy Childbirth. 2007] – PubMed Result