Sunday, April 16, 2006

obesity research

back in january, i posted an entry about the controversy around the size of the “obesity epidemic”. i just received a comment about this, suggesting that the article i had pointed out in that entry was naïve in asking questions about the intentions behind the high publicity that obesity has been receiving lately.

this prompted me to beef up a bit on existing research and thoughts about this topic. what i found confirms my belief that the jury on the connection between obesity and ill health is still out.

again, i have no doubt that in an ideal world, and all things being equal, there is no question that eating moderately is a good idea. however, we don’t live in an ideal world, and all things are not equal.

(sidebar: as i was reflecting on this topic, it occurred to me that the more healthy i live, the more understanding i have for people for whom health is not such a great priority, or who have chosen to focus on different areas of improving their health than i have. i have some hunches regarding what the reason for that might be; fodder for another blog entry, i guess).

anyway, here are some references regarding the obesity-health connection:

  1. obesity is often measured using the BMI (body mass index), which is a way to estimate the ratio of fat to other tissue. the author cautions that in conducting these measurements, once size does not fit all, that there is a wide range in so-called “normal” weight, BMI, and that “a direct relationship between obesity and cardiovascular disease is debated by some authorities”.
  2. this article questions the statistical soundness of the center for disease control’s research on obesity and points to the paradox that while obesity is said to have risen sharply, so has overall life expectancy.
  3. “confusion of the consequences of obesity arise because researchers have used different BMI cut-offs, and because the presence of many medical conditions involved in the development of obesity may confuse the effects of obesity itself.”
  4. study finds government overstated danger of obesity
  5. “this study on adult mortality and obesity involving adult adoptees and their biologic and adoptive parents indicates a genetic influence on the risk of premature death from all causes, from natural causes, infections, and cardio- and cerebrovascular conditions. non-genetic influences are suggested regarding death from the vascular causes and from cancer.”
  6. here is an interesting thought piece on the concepts of “natural death”, “premature death” and “preventable death”, looking at the connection between mortality, lifestyle, cultural ideas around lifestyle, and longevity. a quote:
    It is worthwhile contemplating that the 295,000 American and 39,000 Canadian military deaths which occurred during World War Two all fit the definition of "preventable" deaths.
  7. suggests that there are more deaths in north america due to underweight than to overweight.
  8. a broad range of BMIs are well tolerated by older adults. the minimum mortality (estimated from the fitted proportional hazard models) occurred at a BMI of approximately 31.7 for women and 28.8 for men.”
  9. “compared with normal weight, overweight and obesity did not significantly increase all-cause mortality risk. Compared with low cardio-respiratory fitness (CRF), moderate and high CRF were associated significantly with lower mortality risk. Compared with normal weight, overweight and obesity were not significantly associated with all-cause mortality.”
  10. “among individuals that are not severely obese, weight loss is associated with increased mortality rate and fat loss with decreased mortality rate.”
  11. this article supports the view that childhood overweight is associated with increased mortality risk in later life. the greatest risk is seen in overweight children who become overweight adults or underweight children who become overweight adults. like any study, this study has numerous limitations, first the ones mentioned in the study but most of all the fact that they don’t give any comparisons re the mortality rates of stroke, ischemic heart disease etc. for the general population.
  12. "obesity is strongly predictive of mortality from all causes combined, cardiovascular disease, and some cancers. central [abdominal] obesity may be an even stronger predictor of morbidity and mortality than body weight or BMI, although this remains controversial. the risks … may well reflect the association of these anthropometric variables with underlying insulin resistance or hyperinsulinemia … there is powerful evidence that obesity is detrimental throughout the life span, any time from childhood to old age.”
  13. “1) regular physical activity clearly attenuates many of the health risks associated with overweight or obesity; 2) physical activity appears to not only attenuate the health risks of overweight and obesity, but active obese individuals actually have lower morbidity and mortality than normal weight individuals who are sedentary, and 3) inactivity and low cardiorespiratory fitness are as important as overweight and obesity as mortality predictors.”

pretty contradictory, some of this, wouldn't you say? what do you think?

isabella mori
counselling in vancouver
www.moritherapy.com

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