Tuesday, July 30, 2013

Myths, Assumptions, Nuances and Obesity

I have been writing about health and wellness in one form or another for 13 years. During that time I have gone to graduate school twice.  
My plan for the blog has always been to present information to the public that goes beyond the headlines.
My goal is to educate the reader in the hopes that he or she will take new science and recommendations for better health into consideration.   These recommendations include consuming a quality diet, getting sufficient exercise, limiting sedentary activity and maintaining a weight lean enough to prevent diseases that are associated with adiposity - or over fatness.

My understanding of research has improved over the years, especially the last few, but the science into the causes of obesity (adiposity) has been plagued with flaws.  Scholars far more experienced and critical than I, have begun to point out these flaws.
I tell you this because I am sensitive to the fact that I may have perpetuated false claims in my own blog or given too much credibility and attention to tenuous claims.  This exactly opposite my goal.  

Here I am speaking about diet quality and healthy weight.
It IS still about calories and the sources of those calories, but it is much more nuanced.  By nuanced, I mean that numerous factors are independently and interdependently related to health and weight.  

There are many problems with the methods used in obesity research and that makes it hard to pull together evidence that can suggest a solution.  Science has taught us a lot. We now need to use more precise measurement methods (e.g. with dietary recall, and body fatness), be consistent with our definitions (what is obesity?) and have more open minds about what the causes could be (is it really just too many calories ?).

This was wonderfully explained by Herbert et al (2013) in a commentary published in the journal Mayo Clinic Proceedings.  The summary can be found here.  They give good advice for improving research.  I will apply this advice in my career.

I will continue to talk about calories (food energy availability) and policies, but these are small parts of a very complex, multi -facted system.

Let me quote from the Herbert article.  I assure you that I believe every word in this paragraph.
...obesity arises from the dynamic interplay of the external environment, inclusive of the social milieu, built environment and food energy availability, behavioral and development processes and a variety of genes and epigenetic effects that, in turn, control a myriad of metabolic systems and subsystems that regulate energy intake, energy expenditure and nutritional partitioning.   
Now I will do my best to restate this in simpler terms:

There are many factors both inside and outside of our bodies that work together to create a condition where obesity is likely.  As one factor changes one or more others reacts and these changes and interactions are continual (dynamic). The external environment can make it easy or hard to be physically active (built environment) and easy or hard to eat too many calories (especially nutrient poor ones) (i.e., food energy availability). These two factors are also impacted by social cues (preferences, norms, advertising, ' peer pressure' - i.e., the social milieu).  Behavior is what we do - exercise or not, choose certain foods or drinks, and development is the body changing over time.  Genes, or heredity, are usually activated by some interaction with the outside environment (epigenetics) and together impact how the food a person eats is processed by the body - whether or not one gets high cholesterol, or diabetes for example.

That is a lot to process.  The simplest truth is that one should not eat too much, and a very complex set of circumstances determines if one eats too much and whether their eating too much causes a bad outcome (illness).   I would point out one last thing from the article.. the authors say that it is social and environmental factors, NOT genes, that have had the greatest influence.

So here are 3 interesting links about calories.
Link 1 This is a story about peoples desire for calorie information and how some restaurants are starting to provide lower calorie meals.  It actually summarizes a lot of the research I have used in my literature reviews and in this blog.  I love how it mentions Dardens Restaurants use of nutritionists and calorie counts when creating new entrees.  Also, it points out some REALLY high calorie entrees ~ over 2000.  Oh one problem, the writer keeps referring to the national menu law as a proposed law.  The law is a law.  It has been passed.  The rule - how to follow the law, is being proposed. 
Link 2  This links to a 3 item quiz on which item has the lowest amount of calories... I scored 100.
Link 3  This links to a story about smoothies and juices, both of which I personally avoid at all costs.

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