Wednesday, January 7, 2015

Lesser Known Causes of Obesity

We hear it in the news every day.  There is an obesity epidemic.  We are obese.  We just keep getting fatter and fatter.  

Who's responsible?  We must find someone to blame.  Why not blame the fat people?  Many people in Western society seem to have opted for distancing ourselves from the intolerable and projecting it onto “fat” and "fat people".  Our society's rage against fat as sin today may be comparable to the Victorian attitude about sex. Our desperation to avoid the stigma of fat is reflected in how we spend our money. 
In 2012 in the U.S. alone, the weight-loss industry raked in $61 billion on weight loss foods, food replacement products (i.e. Jenny Craig, Weight Watchers), books, surgeries, diet programmes, and diet supplements (in 1980 that number was $10 billion). 
After all, we can't control our age, our height, our colour, our socioeconomic status at birth, our parentage, our increasingly poisonous environment - we need something to claim control over - right?  If we can't control our body weight, there's no hope for us - right?  Wrong.

Obese people have been found to expend less energy while sleeping and resting than those who are not obese, making it easier to gain weight on lower caloric intake than those with higher resting energy expenditure rates:
"Resting energy expenditure (REE) was investigated by indirect calorimetry in relation to body composition and to different degrees of obesity in order to assess if a defective energy expenditure contributes to extra body fat accumulation …. The analysis showed a negative impact of obesity on REE beyond body composition variables."  (6Verga, p. 47)
Recent research by 12 Dallman suggests that high levels of stress over a long period of time (such as those caused poverty, chronic trauma and childhood abuse) can create changes in the brain that causes the body to redistribute its fat stores to the abdominal area and increases sucrose (sweets) appetite. 


Pagato, et al, 2012 observed that
  • PTSD alters functioning of the HPA axis, which regulates cortisol secretion Cortisol hypothesized to promote obesity
  • Cortisol secretion linked to stress-related weight gain
  • People with PTSD have lower circulating cortisol relative to healthy controls



Ironically, the stigma from being fat, especially as a child, and the consequent vulnerability to ongoing bullying and abuse by peers can set this viscous cycle in motion or exacerbate it early on.

Additional causes of obesity unrelated to compulsive eating were also found by studies from the 7National Institutes for Health, and by 4Heitmann.  Obesity has been shown to have a significant genetic component according to cross-sectional twin and family studies done by 2Coady. And this genetic component is compounded by the tendency of obese people to mate with each other, as they are often excluded from mainstream dating circles.  From  3Hebebrand:
"Our results indicate that assortative mating is common among parents of extremely obese children and adolescents, ascertained between 1995 and 1997. In addition, the parental loading on the tenth decile is most prominent for the most obese children."  (p. 345)
Major Cause of Obesity Epidemic: Weight-Loss Attempts
  • Research on 17,000 children showed that twins who embarked on one intentional weight loss episode were two to three times more likely to become overweight compared to their non-dieting twin counterpart. Furthermore, the risk of becoming overweight increased in a dose-dependent manner, with each dieting episode. #1
  • A 1999 report on 4,193 women and 3,536 men participating in the Finnish Twin Cohort Study revealed that dieters were several times more likely than non-dieters to experience major weight gain (more than 22 pounds) during a follow-up lasting 15 years. (pp.31) #2
#1. Alison E. Field, S. Bryn Austin, C. Barr Taylor, Susan Malspeis, Bernard Rosner (2003)

#2. Korkelia, M., A Rissanen, J Kaprio, TIA Sorensen, & M Koskenvuo (1999)

According to a 2007 Meta-Study (a study of 31 other studies, internationally)

  • Diets do lead to short-term weight loss, on average of 5%–10% of the person's body weight
  • These losses are not maintained
  • The more time that elapses between the end of a diet and the follow-up, the more weight is regained.
  • Among patients who were followed for two or more years, 83% gained back more weight than they lost
  • In studies with the longest follow-up times (of four or five years post-diet), the weight regain trajectories continued to increase suggesting that if participants were followed for even longer, their weight would continue to increase. #3

#3 Mann, T., Tomiyama, AJ, Westling,E, Lew, AM, Samuels, B. (2007) Medicare’s Search for Effective Obesity Treatments in American Psychologist Vol. 62, No. 3, 220–233

Putting people on caloric restriction regimens is bound to fail, as their bodies will tell them that they are not getting enough to eat (they will have a constant nagging hunger that will only ease up when they eat).  Checking for medications that cause weight gain, educating about food additives such as trans fatty acids or trans-fats, explaining about the connections between genes, stress, childhood abuse and body size to de-stigmatise, and encouraging an increase in activity levels with guidance on how to incorporate regular exercise into daily routines is the only humane prescription for obesity when it is not related to overeating.

References:
2Coady, S.A., Jaquish, C.E., Fabsitz, R.R., Larson, M.G., Cupples, L.A., & Myers, R.H. (2002). Genetic variability of adult body mass index: a longitudinal assessment in Framingham families. Obesity Research, 10, 675-81.

1aColditz, G.A. (1992). Economic costs of obesity. American Journal of Clinical Nutrition, 55, 503-507.
12Dallman, M.F., Pecorary, N., Akana, S.F., la Fleur, S.E., Gomez, F., houshyar, H., Bell, M.E., Bhatnagar, S., Laugero, K.D., and Manalo, S. (2003) Chronic stress and obesity: A new view of "comfort food".  Proceedings of the National Academy of Sciences of the USA, 100/20, 11696-11701
11 Trust for America's Health Report. (2005). F as in Fat: How obesity policies are failing in America.
10Farley, Tom,  (2005). Prescription for a Healthy Nation : A New Approach to Improving Our Lives by Fixing Our Everyday World. Boston: Beacon Press
8Gallagher, D., Testolin, C., Heshka, S., & Heymsfield, S.B. (n.d.). Body mass index: Differential misclassification of under and over-fatness. New York City: Obesity Research Center, St.
3Hebebrand, J., Wulftange, H., Goerg, T., Ziegler, A., Hinney, A., Barth, N., Mayer, H., & Remschmidt, H. (2000). Epidemic obesity: are genetic factors involved via increased rates of assortative mating? International Journal of Obesity Related Metabolic Disorders, 24, 345-53
4Heitmann, B.L., Harris, J.R., Lissner, L., & Pedersen, N.L. (1999). Genetic effects on weight change and food intake in Swedish adult twins. American Journal of Clinical Nutrition, 69, 597-602.
1bMetropolitan Life Insurance Company (1983). Metropolitan height and weight tables. New York: Author.
7National Institutes for Health (2001). Understanding adult obesity. NIH Publication No. 01-3680. Washington, DC: U.S. Government Printing Office.
5U.S. Department of Health and Human Services, Centers for Disease Control and Prevention (1996). Physical activity and health: A report of the surgeon general. Washington, DC: U.S. Government Printing Office.
6Verga, S, Buscemi, S., & Caimi, G. (1994). Resting energy expenditure and body composition in morbidly obese, obese and control subjects. Acta Diabetologia, 31(1), 47-51.
 
  

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