Personality Research and Obesity

July 13th, 2016 No comments »

Frequently, discussions about persons with obesity will include a view that persons with obesity have a personality defect which impedes their ability to limit food intake or sustain a regimen of physical activity. Rather than ignore such views, it might be helpful to see how research on personality and obesity provides us with enhanced understanding. A series of papers by Dr. Angela Sutin and colleagues provides helpful insights. A 2011 paper found that the most disciplined consumers had lower rates of obesity while large weight gains were found among consumers scoring high on measures of impulsiveness, low conscientiousness and willingness to take risks.  (These are standard categories for assessing personality types.) (Sutin AR, Ferrucci L, Zonderman AB, Terracciano A. Personality and obesity across the adult life span J Pers Soc Psychol 2011 Sep;101(3):579-92) Going further, a 2013 paper by Sutin and colleagues found that persons who rated high on impulsiveness and lacked discipline or low conscientiousness had high circulating levels of leptin, which plays a critical role in weight regulation, even after controlling for body mass index, waist circumference or inflammatory markers. (Sutin AR, Zonderman AB, Uda M, Deiana B et al Personality Traits and Leptin Psychosom Med. 2013 Jun;75(5):505-9)

A third paper by Sutin and colleagues, “I Know Not to but I Can’t Help It: Weight Gain and Changes in Impulsivity Related Personality Traits,” asked whether weight gain or loss of 10% or more led to personality changes, specifically impulsiveness and deliberation. The researchers found that compared to participants who remained weight stable, those who gained weight became more impulsive. Those who did not gain weight showed a predicted loss in impulsiveness. But contrary to their hypothesis, weight gain was also associated with increases in deliberation. In other words, subjects who were gaining weight became more thoughtful before acting. The authors opined that as participants gained weight they bought into the American stereotypes about persons with obesity. So they saw themselves as more impulsive even as they were increasing in deliberativeness. There had no change in self-discipline.

A recent paper has found that only conscientiousness showed a robust association with both BMI and obesity risk. Conscientiousness was associated with obesity risk among Hispanics and is larger for women than men. (Kim, J. Personality traits and body weight: Evidence using sibling comparisons. Soc Sci Med 2016 Jul 1:163:54-62)

The Biggest Loser study shows persistence of slower metabolism after 6 years

May 2nd, 2016 No comments »

Gina Kolata of The New York Times has a front-page story on May 2, 2016, covering a study of winners of the TV ‘reality’ show, The Biggest Loser. The study published in the journal Obesity shows that not only is most the lost weight regained, but that the slower metabolic rate, which occurs during active weight loss, persists for up to 6 years in the subjects. This is the process of adaptive thermogenesis which we have discussed on several occasions. What the article does not mention is that most of the weight loss programs used in employer wellness programs are based on The Biggest Loser. In other words, thanks to Obamacare, employees can be penalized for failing at a weight loss program where failure is all but assured.

National Over-Feeding Months

November 27th, 2015 No comments »

It often seems as if the period from Labor Day in September through Halloween in October, Thanksgiving in November, Christmas in December, New Year in January, Valentine’s Day and the football playoffs in February are  designed to promote overeating. It is a wonder we all are not obese. So amid the food celebration and token diet advice, it’s nice to have some solid, research-based exposition of  the myths surrounding weight loss and weight gain. We have one, thanks to Kevin Hall, Ph.D., a distinguished researcher at the National Institutes of Health. (For coverage of Dr. Hall’s recent work, click here.)

Study Affirms that Central Obesity has Higher Mortality Risk

November 21st, 2015 No comments »

A new article reaffirms earlier studies showing that in persons with a normal Body Mass Index (BMI) had the worst long-term survival compared to others with a similar BMI but no central obesity and twice the mortality risk of persons who were overweight or obese according to BMI.

 

Junk Food Gets Death Row Reprieve

November 6th, 2015 No comments »

A new study has given a reprieve for junk food as a cause of obesity. David Just and Brian Wansink at the Cornell University Food and Brand Laboratory found that the intake  of these foods (soda, candy, and fast food) are not related to Body Mass Index (BMI) in the average American adult.  Using NHANES data (which has its issues) they found that consumption of soda, candy and fast food is not linked to BMI for 95% of the population. The exception is for those who are underweight or who have Class III obesity (formerly morbid obesity). Dr. Just explained, “This means that diets and health campaigns aimed at reducing and preventing obesity may be off track if they hinge on demonizing specific food. If we want real change we need to look at the overall diet, and physical activity. Narrowly targeting junk foods is not just ineffective, it may be self-defeating as it distracts from the real underlying causes of obesity.

These findings are consistent with other recent studies. In a 2011 study, James Hill and colleagues found that changes in diet were consistent across normal, overweight and obesity groups. Energy intake increased in all groups. Likewise, in 2013, Yancy and colleagues found that, over 4 decades, trends in energy and macronutrients were similar across BMI classes.

A word of caution. These studies rely on BMI categories. Whether macronutrients or junk food have a greater deleterious effect on waist-hip ratio or increases in visceral adiposity remains to be determined.

 

CDC Spins Breastfeeding-Obesity Link

October 27th, 2015 No comments »

CDC is continuing to perpetuate the old canard that breastfeeding is protective against childhood obesity. In the recently released publication, Vital Signs: Improvements in Maternity Care Policies and Practices that Support Breastfeeding-United States, 2007-2013,  the CDC states “In addition, evidence suggests that breastfeeding is associated with a reduction in the risk for obesity and diabetes in children (3).”

The reference is a 2007 evidence report on CDC’s sister agency, the Agency for Healthcare Research and  Quality website. However, unlike several other citations, there is no link to the paper. Why? Perhaps because AHRQ identifies the paper as “Archived” and states, “It (the paper) was current when produced and now may be out of date.” Here’s the link:  http://archive.ahrq.gov/clinic/tp/brfouttp.htm#Report.

Maybe out of date? No fooling! See here, here and here for updated research which CDC decided to overlook.

 

The Putative 104 Causes of Obesity Update

October 22nd, 2015 No comments »

What causes obesity? The question has profound implications for individuals and policy makers. So, it is natural to turn to research published in peer-reviewed journals to find the answer. So, we have updated the list of “putative” causes first published on February 28, 2013 and  updated on September 1, 2013. We have moved from 82 putative causes to 104.

The number of putative causes raises several questions. First, is there some problem with the research methodology that so many and diverse potential causes are identified? Second, are a number of named putative causes symptoms or manifestations of underlying, deeper causes? And what are those? Third, to what extent are identified putative causes reflections of local, regional, ethnic or cultural factors. Finally, many of these studies point out that the “energy-in-energy-out” formulation for the cause of obesity which most of the public and health professionals believe to be the cause.

New items on the list include too much homework, insufficient body heat, imagining the smell of food, components of dust, living with grandparents, thermogenic adipocytes, estrogens and starting college.

Here’s the most current list. If I am missing any, please let me know. (The links are not meant to be definitive or best study but merely a demonstration of the interest in the particular cause.)

1. agricultural policies

2. air conditioning,

3. air pollution,

4. antibiotic usage at early age,

5. arcea nut chewing,

6. artificial sweeteners,

7.  Asian tiger mosquitos,

8. assortative mating,

9. being a single mother,

10. birth by C-section,

11. built environment,

12. celebrity chefs,

13. chemical toxins, (endocrine disruptors)

14. child maltreatment,

15. compulsive buying,

16. competitive food sales in schools,

17. consuming skim milk in preschool children,

18. consumption of pastries and chocolate (in Burkina Faso),

19. decline in occupational physical activity,

20. delayed prenatal care,

21. delayed satiety,

22. depression

23. driving children to school

24. eating away from home

25. economic development (nutrition transition)

26. entering into a romantic relationship,

27. epigenetic factors,

28. eradication of Helicobacter pylori,

29. family conflict,

30. family divorce,

31. first-born in family,

32. food addiction,

33. food deserts,

34. food insecurity,

35. food marketing to  children,

36. food overproduction,

37. friends,

38. genetics,

39. gestational diabetes,

40. global food system,(international trade policies)

41. grilled foods,

42. gut microbioata,

43. having children, for women,

44.  heavy alcohol consumption,

45.  home labor saving devices,

46. hormones (insulin,glucagon,ghrelin),

47. hunger-response to food cues,

48. high fructose corn syrup,

49. interpersonal violence,

50. lack of family meals,

51. lack of nutritional education,

52. lack of self-control,

53. large portion sizes,

54.  living in crime-prone areas,

55. low educational levels for women,

56. low levels of physical activity,

57. low Vitamin D levels,

58.  low socioeconomic status,

59. market economy,

60. marrying in later life

61. maternal employment,

62. maternal obesity,

63. maternal over-nutrition during pregnancy,

64. maternal smoking,

65. meat consumption,

66. menopause,

67. mental disabilities,

68. no or short term breastfeeding,

69. non-parental childcare

70. outdoor advertising,

71. overeating,

72. participation in Supplemental Nutrition Assistance Program (formerly Food Stamp Program)

73. perceived weight discrimination,

74. perception of neighborhood safety,

75. physical disabilities,

76. prenatal  maternal exposure to natural disasters,

77. poor emotional coping

78. sleep deficits,

79. skipping breakfast,

80. snacking,

81. smoking cessation,

82. spanking children,

83. stair design

84. stress, artificial lighting, air conditioning,

85.  sugar-sweetened beverages,

86. taste for fat

87.  trans fats,

88. transportation by car,

89. television set in bedrooms

90. television viewing,

91. thyroid dysfunction

92. vending machines,

93. virus,

94. weight gain inducing drugs,

95. working long hours,

96. NEW too much homework,

97. NEW insufficient body heat,

98. NEW imagining the smell of food,

99. NEW dust components,

100. NEW living with grandparents in China,

101. NEW estrogens,

102. NEW thermogenic adipocytes,

103. NEW prenatal exposure to cigarette smoke,

104. NEW starting college.

 

Overselling Breastfeeding

October 21st, 2015 No comments »

Courtney Jung has an interesting opinion piece in the New York Times, “Overselling Breastfeeding.” The writer points out that the goals for the duration of breastfeeding are more accessible to upper and middle-class white women than other mothers. Furthermore, she decries the drift from making breastfeeding a choice for mothers to make to policy decisions which penalize non-breastfeeding mothers. She writes, “Demographic differences in breastfeeding rates also justify government interventions that punish poor women who do not breastfeed. This isn’t just the little unobtrusive little “nudge” in the right direction, designed to compel people to make better decisions. It’s more like a shove, with a kick for good measure.”

Jung notes that arguments that breastfeeding prevents childhood obesity have been largely disproved. See our analysis on this point.