Showing posts with label twin studies. Show all posts
Showing posts with label twin studies. Show all posts

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.
 
  

Dieting is Bad for You

Dieting is Bad for You. But I Don't Diet Anymore - I know Better!

 

Don't be fooled - If you're "only trying to eat healthier," ask yourself these questions:

  1. Does this "new way of eating lifestyle" require that I change my eating habits to omit or considerably limit one of the three major food groups that all humans need to survive: carbohydrates, proteins, or fats?
  2. Does this "fitness fat-burner menu" cause me to wait to eat for long periods while hungry or to stop eating before my physical appetite is satisfied?
  3. Does this "high nutrition program" require that I eat according to externally dictated menus and schedules, which distract me from my inner rhythms of hunger and satiation?

Food Group or Caloric Restriction = Thin = Better Health?


Thin, very temporarily yes. Better Health -No - Plus, studies show that the best way to gain weight AND to develop an eating problem is to restrict your diet (see below). 

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

Fat Phobia Kills

A study of 36,000 students in Minnesota found that negative body image is associated with a higher suicide risk for girls #4

#4. American Association of University Women (1990). Shortchanging girls, shortchanging America: Full data report. Washington, DC: American Association of University Women.

Overweight girls are far more likely to engage in dangerous practices (fasting, smoking, vomiting, taking laxatives) to lose weight than normal weight girls #5

#5. Wertheim, E., Paxton, S., & Blaney, S. (2009)

The Mayo Clinic researchers note that many adolescents with eating disorders have had a history of being overweight or obese #6

#6. Sim, L.A., Lebow, J, & Billings, M, (2013)

A longitudinal study published in 1999 showed that girls who dieted severely were 18 times more likely to develop an eating disorder #7

#7.  Patton et al (1999)

Even here in Aotearoa New Zealand:

Studies indicate that although 75% of 15 year old girls were ‘healthy weights’ 68% of them wanted to weigh less #8

#8. Worsley, Worsley, McConnon & Silva (1990)

Of the girls that reported dieting, most had started prior to the age of 13 years. #9

#9. Fear, Bulik & Sullivan (1996) 

We have known since the 70's that dietary restriction sets a dangerous trend, And we now know that this trend is far more "dangerous" than the "obesity epidemic" that gets so much more press but that fails to mention that the health risks of obesity are much more related to a lack of physical exercise than to BMI. It is perfectly possible to be "fit and fat"" where it is less possible to be "fit and dieting."

Why Do We Keep Trying to Lose Weight by Restricting Food Types or Intake?


In spite of all this, our drive to diet and get thinner and thinner is getting worse not better. And our children and teenagers continue to get the wrong messages

  • Parental messages about body image and teasing by others (e.g. peers and/or family) have been highly correlated with body image dissatisfaction and eating disorder symptoms #10

#10. Thelen and Cormier, 1995

Because Dieting is Addicting

Compulsions and addictions are defined by one's inability to stop behaviour in spite of known harmful consequences. Given all of the evidence above, why would anyone want to deliberately deprive themselves of food anymore? We know it causes eating disorders, suicidality, and ultimately either death or greater weight gain - this evidence isn't even new. Yet we keep doing it - why?

Dieting, like many addictions, creates false promises. Like gamblers who know full well that the odds are against them, most dieters think they can buck the odds because the false promise - thinness and an end to weight discrimination - is too seductive to ignore or dismiss. The pain of continuing to suffer teasing, discrimination, and judgments overshadows the likelihood of dieting failure. No one wants to really believe they can't diet their way to thinness - it feels too hopeless, too awful. And although exercise offers an escape from most of the physical health risks of a high body weight, it can't promise a quick perfect body. And we humans are famous for looking at the short term results and ignoring the long term, if it doesn't suit us. A gambler makes one big win, then continues to gamble until it's all gone and then some - this is the same thinking as "diet think."

More Myths

BMI, or the Body Mass Index, was originally developed as a statistical tool to study large populations over time. It is completely irrelevant to individual weight and does not even distinguish between weight caused by fat or muscle. Similar to that old fashioned standby, the Metropolitan Life Height and Weight Charts, the original uses for which these devices were developed has gotten completely distorted. Met Life was originally an actuarial study - a statistical population study based on people who buy life insurance. What happened to scientific measures - controlled, double-blind studies that limit the variables they measure? When it comes to weight, our scientific standards seem to take a back seat. This is because no one, including doctors, is immune to cultural pressures, assumptions and stereotypes. Although medical practitioners the world over are trained to used the BMI now as they were the Met Life Charts in the past, they are rarely taught that they are highly inaccurate in evaluating individual weight and fitness.

One of the medical criteria of anorexia nervosa: body weight 15 % below a weight that is considered "normal", is met by the majority of models and beauty contestants.

So, What Size Should I Be?

Since there are no clear markers for healthy body weight that are free from highly questionable social standards, I would maintain that healthy body weight is highly individual and relative, given the various causes of weight gain

Perhaps it is best to consider the size a person naturally returns to after a long period of both non-compulsive eating and consistent exercise commensurate with the person' s physical health and condition. We must learn to advocate for ourselves and our children to aspire to a naturally determined size, even though that will often mean confronting misinformed family, friends, and media advertising again and again.

If you want to know if you are fit, ask yourself how you feel. Do you have energy or do you drag through the day? Are you physically active at least a half hour a day (this means pushing yourself to do something that causes you to pant and sweat)? If not, consider increasing your level of physical activity in such a way that it is woven into your day (e.g. walking or cycling instead of driving).

The benefits of regular physical activity have been demonstrated scientifically again and again - as have the disadvantages of restrictive dieting. It makes sense that we need to be active - we were hunter- gatherers for 100,000 years and had to travel huge distances to follow the edible flora and fauna. We're supposed to move around - and then we're supposed to eat! 

Are you Overeating?


Do you feel overstuffed a good deal of the time, or do you rarely let yourself feel hungry? Do you eat to cope with issues that have nothing to do with hunger? 

What is Non-Compulsive Eating?

Simply stated, non-compulsive eating means eating when you are hungry and stopping when you are satisfied. This involves being able to distinguish emotional hunger from physical hunger, and satiation from over-fullness. This approach, combined with regular physical activity, over the long term,will bring about a healthy ratio of fat to muscle, even if you don't end up looking like a fashion model.