Couch Potato
The Effects of Reality Television on Weight Bias: An Examination of The Biggest Loser
Sarah Domoff et al.
Obesity, forthcoming
Abstract:
Weight-loss reality shows, a popular form of television programming, portray obese individuals and their struggles to lose weight. While the media is believed to reinforce obesity stereotypes and contribute to weight stigma, it is not yet known whether weight-loss reality shows have any effect on weight bias. The goal of this investigation was to examine how exposure to 40-min of The Biggest Loser impacted participants' levels of weight bias. Fifty-nine participants (majority of whom were white females) were randomly assigned to either an experimental (one episode of The Biggest Loser) or control (one episode of a nature reality show) condition. Levels of weight bias were measured by the Implicit Associations Test (IAT), the Obese Person Trait Survey (OPTS), and the Anti-fat Attitudes scale (AFA) at baseline and following the episode viewing (1 week later). Participants in The Biggest Loser condition had significantly higher levels of dislike of overweight individuals and more strongly believed that weight is controllable after the exposure. No significant condition effects were found for implicit bias or traits associated with obese persons. Exploratory analyses examining moderation of the condition effect by BMI and intention to lose weight indicated that participants who had lower BMIs and were not trying to lose weight had significantly higher levels of dislike of overweight individuals following exposure to The Biggest Loser compared to similar participants in the control condition. These results indicate that anti-fat attitudes increase after brief exposure to weight-loss reality television.
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The Psychological Weight of Weight Stigma
Brenda Major, Dina Eliezer & Heather Rieck
Social Psychological and Personality Science, forthcoming
Abstract:
The authors theorized that overweight individuals experience social identity threat in situations that activate concerns about weight stigma, causing them to experience increased stress and reduced self-control. To test these predictions, women who varied in body mass index (BMI) gave a speech on why they would make a good dating partner. Half thought they were videotaped (weight visible); the remainder thought they were audiotaped (weight not visible). As predicted, higher BMI was associated with increased blood pressure and poorer performance on a measure of executive control when weight was visible and concerns about stigma were activated but not when weight was not visible. Compared to average weight women, overweight women also reported more stress-related emotions when videotaped versus audiotaped. Findings suggest that weight stigma can be detrimental to mental and physical health and deplete self-regulatory resources necessary for weight control.
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Kathleen Keller et al.
Obesity, forthcoming
Abstract:
Animal studies show that CD36, a fatty acid translocase, is involved in fat detection and preference, but these findings have not been reported in humans. The objective of this study was to determine whether human genetic variation in 5 common CD36 polymorphisms is associated with oral fat perception of Italian salad dressings, self-reported acceptance of high-fat foods and obesity in African-American adults (n = 317). Ratings of perceived oiliness, fat content, and creaminess were assessed on a 170-mm visual analogue scale (VAS) in response to salad dressings that were 5%, 35%, and 55% fat-by-weight content. Acceptance of added fats and oils and high-fat foods was self-reported and anthropometric measures were taken in the laboratory. DNA was isolated from saliva and genotyped at 5 CD36 polymorphisms. Three polymorphisms, rs1761667, rs3840546, and rs1527483 were associated with the outcomes. Participants with the A/A genotype at rs1761667 reported greater perceived creaminess, regardless of the fat concentration of the salad dressings (P < 0.01) and higher mean acceptance of added fats and oils (P = 0.02) compared to those with other genotypes at this site. Individuals who had C/T or T/T genotypes at rs1527483 also perceived greater fat content in the salad dressings, independent of fat concentration (P = 0.03). BMI and waist circumference were higher in participants who were homozygous for a deletion (D/D) at rs3840546, compared to I/D or D/D individuals (P < 0.001), but only 2 D/D individuals were tested, so this finding needs replication. This is the first study to demonstrate an association between common variants in CD36 and fat ingestive behaviors in humans.
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Obesity, SES, and Economic Development: A Test of the Reversal Hypothesis
Fred Pampel
Social Science & Medicine, forthcoming
Abstract:
Studies of individual countries suggest that socioeconomic status (SES) and weight are positively associated in lower-income countries but negatively associated in higher-income countries. However, this reversal in the direction of the SES-weight relationship and arguments about the underlying causes of the reversal need to be tested with comparable data for a large and diverse set of nations. This study systematically tests the reversal hypothesis using individual- and aggregate-level data for 67 nations representing all regions of the world. In support of the hypothesis, we find not only that the body mass index, being overweight, and being obese rise with national product but also that the associations of SES with these outcomes shift from positive to negative. These findings fit arguments about how health-related, SES-based resources, costs, and values differ across levels of economic development. Although economic and social development can improve health, it can also lead to increasing obesity and widening SES disparities in obesity.
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Educational Differences in Obesity in the United States: A Closer Look at the Trends
Yan Yu
Obesity, forthcoming
Abstract:
Both body weight and educational attainment have risen in the United States. Empirical evidence regarding educational differences in obesity (BMI ≥30) is inconsistent. According to some widely cited claims, these differences have declined since the 1970s, and the most educated have experienced the greatest gain in obesity. Prior research was limited in grouping college graduates with nongraduates, combining men and women in the same analysis, and using self-reported rather than measured anthropometric information. Using the National Health and Nutrition Examination Surveys (NHANES), we address these issues and examine changing educational differences in obesity from 1971-1980 to 1999-2006 for non-Hispanic whites and blacks in two separate age groups (25-44 vs. 45-64 years). We find that (i) obesity differentials by education have remained largely stable, (ii) compared with college graduates, less educated whites and younger black women continue to be more likely to be obese, (iii) but the differentials are larger for women than men, and weak or nonexistent among black men and older black women. There are exceptions to the overall trend. The obesity gap has widened between the two groups of college-educated younger women, but disappeared between the least and most educated younger white men. Thus, the increase in obesity was similar for most educational groups, but significantly greater for younger women with some college and smaller for younger white men without a high-school degree. Lumping together the two distinct college groups has biased previous estimates of educational differences in obesity.
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Economic growth and obesity: An interesting relationship with world-wide implications
Garry Egger, Boyd Swinburn & Amirul Islam
Economics & Human Biology, forthcoming
Abstract:
The prosperity of a country, commonly measured in terms of its annual per capita Gross Domestic Product (GDP), has different relationships with population levels of body weight and happiness, as well as environmental impacts such as carbon emissions. The aim of this study was to examine these relationships and to try to find a level of GDP, which provides for sustainable economic activity, optimal happiness and healthy levels of mean body mass index (BMI). Spline regression analyses were conducted using national indices from 175 countries: GDP, adult BMI, mean happiness scores, and carbon footprint per capita for the year 2007. Results showed that GDP was positively related to BMI and happiness up to ∼$US3,000 and ∼$5,000 per capita respectively, with no significant relationships beyond these levels. GDP was also positively related to CO2 emissions with a recognised sustainable carbon footprint of less than 5 tonnes per capita occurring at a GDP of <$US15,000. These findings show that a GDP between $US5-$15,000 is associated with greater population happiness and environmental stability. A mean BMI of 21-23 kg/m2, which minimises the prevalence of underweight and overweight in the population then helps to define an ideal position in relation to growth, which few countries appear to have obtained. Within a group of wealthy countries (GDP > $US30,000), those with lower income inequalities and more regulated (less liberal) market systems had lower mean BMIs.
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Acute Sleep Deprivation Enhances the Brain's Response to Hedonic Food Stimuli: An fMRI Study
Christian Benedict et al.
Journal of Clinical Endocrinology & Metabolism, forthcoming
Context: There is growing recognition that a large number of individuals living in Western society are chronically sleep deprived. Sleep deprivation is associated with an increase in food consumption and appetite. However, the brain regions that are most susceptible to sleep deprivation-induced changes when processing food stimuli are unknown.
Objective: Our objective was to examine brain activation after sleep and sleep deprivation in response to images of food.
Intervention: Twelve normal-weight male subjects were examined on two sessions in a counterbalanced fashion: after one night of total sleep deprivation and one night of sleep. On the morning after either total sleep deprivation or sleep, neural activation was measured by functional magnetic resonance imaging in a block design alternating between high- and low-calorie food items. Hunger ratings and morning fasting plasma glucose concentrations were assessed before the scan, as were appetite ratings in response to food images after the scan.
Main Outcome Measures: Compared with sleep, total sleep deprivation was associated with an increased activation in the right anterior cingulate cortex in response to food images, independent of calorie content and prescan hunger ratings. Relative to the postsleep condition, in the total sleep deprivation condition, the activation in the anterior cingulate cortex evoked by foods correlated positively with postscan subjective appetite ratings. Self-reported hunger after the nocturnal vigil was enhanced, but importantly, no change in fasting plasma glucose concentration was found.
Conclusions: These results provide evidence that acute sleep loss enhances hedonic stimulus processing in the brain underlying the drive to consume food, independent of plasma glucose levels. These findings highlight a potentially important mechanism contributing to the growing levels of obesity in Western society.
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Kate Tchanturia et al.
PLoS ONE, January 2012, e28331
Background: People with eating disorders (ED) frequently present with inflexible behaviours, including eating related issues which contribute to the maintenance of the illness. Small scale studies point to difficulties with cognitive set-shifting as a basis. Using larger scale studies will lend robustness to these data.
Methodology/Principal Findings: 542 participants were included in the dataset as follows: Anorexia Nervosa (AN) n = 171; Bulimia Nervosa (BN) n = 82; Recovered AN n = 90; Healthy controls (HC): n = 199. All completed the Wisconsin Card Sorting Task (WCST), an assessment that integrates multiple measurement of several executive processes concerned with problem solving and cognitive flexibility. The AN and BN groups performed poorly in most domains of the WCST. Recovered AN participants showed a better performance than currently ill participants; however, the number of preservative errors was higher than for HC participants.
Conclusions/Significance: There is a growing interest in the diagnostic and treatment implications of cognitive flexibility in eating disorders. This large dataset supports previous smaller scale studies and a systematic review which indicate poor cognitive flexibility in people with ED.
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Monika Krzyżanowska & Nicholas Mascie-Taylor
Journal of Biosocial Science, March 2012, Pages 221-228
Abstract:
Using a sample of 2090 British father and son pairs the relationships between social and geographical intra- and inter-generational mobility were examined in relation to height, weight and body mass index (BMI). There was much more social mobility than geographical (regional) migration. Social mobility and geographical migration were not independent: socially non-mobile fathers and sons were more likely to be geographical non-migrants, and upwardly socially mobile fathers and sons were more likely to be regional migrants. Upwardly socially mobile fathers and sons were, on average, taller and had a lower BMI than non-mobile and downwardly mobile fathers and sons. In general, no significant associations were found between geographical migration and height or weight. Migrating fathers had a lower BMI than sedentes, as did their sons who migrated between 1965 and 1991. There was no significant interaction that indicated that social mobility and geographical migration were acting in a simple additive way on height, weight and BMI.
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Obesity and Pain Are Associated in the United States
Arthur Stone & Joan Broderick
Obesity, forthcoming
Abstract:
Recent small-scale studies have shown a positive association between central obesity and self-reported pain levels. This study attempts to replicate the finding in a survey of over 1,000,000 individuals in the United States. The Gallup Organization conducted a proprietary survey between 2008 through 2010 where 1,062,271 randomly selected individuals in the United States participated in a telephone interview. Survey questions included height and weight, from which BMI was computed, questions about pain conditions in the past year, and a question about pain experience yesterday. Only 19.2% of the sample was classified as Low-Normal BMI, 21.4 were classified as Overweight, and the remainder was in the three categories of Obese. BMI and pain yesterday were reliably associated when demographic variables were controlled: the overweight group reported 20% higher rates of pain than Low-Normal group, 68% higher for Obese I group, 136% higher for Obese II group, and 254% higher for Obese III group. The association held for both men and women and it became stronger in older age groups. Controlling the associations for other pain-related medical conditions substantially reduced the associations, but they remained substantial for the Obese groups. We conclude that BMI and daily pain are positively correlated in the United States: people who are obese are considerably more prone to having daily pain. The association is robust and holds after controlling for several pain conditions and across gender and age. The increasing BMI-pain association with older ages suggests a developmental process that, along with metabolic hypotheses, calls out for investigation.
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Evidence of Motivational Influences in Early Visual Perception: Hunger Modulates Conscious Access
Rémi Radel & Corentin Clément-Guillotin
Psychological Science, forthcoming
"Although food deprivation did not affect the reported visibility of neutral words, t(40) = 0.48, n.s., fasting participants rated the visibility of food-related words higher (M = 5.48, SD = 1.42) than satiated participants did (M = 4.52, SD = 1.51), t(40) = 2.06, p < .05...The research reported here extends the generally accepted concept that people tend to see what they want to see (e.g., Balcetis & Dunning, 2006). Whereas the results of previous studies could be explained by an implicit bias occurring at a postperceptual stage, our findings indicate that motivation directly improves perceptual encoding of desired stimuli. This demonstration of a modulation of conscious access reveals that motivational influences can penetrate early perceptual processing. Specifically, our results imply that the stimuli were quickly processed unconsciously on a semantic level, and that the stimuli most relevant to participants' goals were most likely to be selected to reach consciousness."
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"Theory of food" as a neurocognitive adaptation
John Allen
American Journal of Human Biology, forthcoming
Abstract:
Human adult cognition emerges over the course of development via the interaction of multiple critical neurocognitive networks. These networks evolved in response to various selection pressures, many of which were modified or intensified by the intellectual, technological, and sociocultural environments that arose in connection with the evolution of genus Homo. Networks related to language and theory of mind clearly play an important role in adult cognition. Given the critical importance of food to both basic survival and cultural interaction, a "theory of food" (analogous to theory of mind) may represent another complex network essential for normal cognition. I propose that theory of food evolved as an internal, cognitive representation of our diets in our minds. Like other complex cognitive abilities, it relies on complex and overlapping dedicated neural networks that develop in childhood under familial and cultural influences. Normative diets are analogous to first languages in that they are acquired without overt teaching; they are also difficult to change or modify once a critical period in development is passed. Theory of food suggests that cognitive activities related to food may be cognitive enhancers, which could have implications for maintaining healthy brain function in aging.
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Impact of Physician BMI on Obesity Care and Beliefs
Sara Bleich et al.
Obesity, forthcoming
Abstract:
Using a national cross-sectional survey of 500 primary care physicians conducted between 9 February and 1 March 2011, the objective of this study was to assess the impact of physician BMI on obesity care, physician self-efficacy, perceptions of role-modeling weight-related health behaviors, and perceptions of patient trust in weight loss advice. We found that physicians with normal BMI were more likely to engage their obese patients in weight loss discussions as compared to overweight/obese physicians (30% vs. 18%, P = 0.010). Physicians with normal BMI had greater confidence in their ability to provide diet (53% vs. 37%, P = 0.002) and exercise counseling (56% vs. 38%, P = 0.001) to their obese patients. A higher percentage of normal BMI physicians believed that overweight/obese patients would be less likely to trust weight loss advice from overweight/obese doctors (80% vs. 69%, P = 0.02). Physicians in the normal BMI category were more likely to believe that physicians should model healthy weight-related behaviors - maintaining a healthy weight (72% vs. 56%, P = 0.002) and exercising regularly (73% vs. 57%, P = 0.001). The probability of a physician recording an obesity diagnosis (93% vs. 7%, P < 0.001) or initiating a weight loss conversation (89% vs. 11%, P ≤ 0.001) with their obese patients was higher when the physicians' perception of the patients' body weight met or exceeded their own personal body weight. These results suggest that more normal weight physicians provided recommended obesity care to their patients and felt confident doing so.
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Looks Good Enough to Eat: How Food Plating Preferences Differ Across Cultures and Continents
Francesca Zampollo et al.
Cross-Cultural Research, February 2012, Pages 31-49
Abstract:
Food is central to cross-cultural studies of behavior, thought, and symbolism. The way it is presented to people, however, can have a dramatic influence on how palatable it is perceived and what is eaten. Because of this, issues of food plating and presentation are of applied interest to anyone who wishes to influence the perceptions and consumption of prepared food. This includes chefs, marketers, and parents. This study examines two questions: (a) What are these visual preferences of plating, and (b) How do they vary across cultures? To explore these questions, we presented a wide range of meal photos to adults from the United States, Italy, and Japan to assess preferences for various plating arrangements. Across six visual dimensions of food, there was a consistent preference for the number of colors on a plate (three), components on a plate (three to four) and the fill level of a plate; however, there were diverging preferences regarding the preferred position of the featured main course, how the items should be organized, and whether they should be casually presented. We discuss the implications of our findings for cross-cultural researchers as well as those who wish to influence the perceptions and food consumption of others.
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Measuring Availability of Healthy Foods: Agreement Between Directly Measured and Self-reported Data
Latetia Moore, Ana Diez Roux & Manuel Franco
American Journal of Epidemiology, forthcoming
Abstract:
A major challenge in studies of the impact of the local food environment is the accuracy of measures of healthy food access. The authors assessed agreement between self-reported and directly measured availability of healthful choices within neighborhood food stores and examined the validity of reported availability using directly measured availability as a "gold standard." Reported availability was measured via a phone survey of 1,170 adults in Baltimore, Maryland, in 2004. Directly measured availability was assessed in 226 food stores in 2006 using a modified Nutrition Environment Measures Survey in Stores (NEMS-S). Whites, college-educated individuals, and higher income households (≥$50,000) had significantly higher reported and directly measured availability than did blacks, those with less education, and lower income households. Persons in areas with above average directly measured availability reported above average availability 70%-80% of the time (sensitivity = 79.6% for all stores within 1 mile (1.6 km) of participants' homes and 69.6% for the store with the highest availability within 1 mile). Those with below average directly measured availability reported low availability only half the time. With revisions to improve specificity, self-reported measures can be reasonable indicators of healthy food availability and provide feasible proxy measures of directly assessed availability.