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Thursday, June 24, 2010

The Psychology of Eating


Do Consumer Price Subsidies Really Improve Nutrition?

Robert Jensen & Nolan Miller
NBER Working Paper, June 2010

Many developing countries use food-price subsidies or price controls to improve the nutrition of the poor. However, subsidizing goods on which households spend a high proportion of their budget can create large wealth effects. Consumers may then substitute towards foods with higher non-nutritional attributes (e.g., taste), but lower nutritional content per unit of currency, weakening or perhaps even reversing the intended impact of the subsidy. We analyze data from a randomized program of large price subsidies for poor households in two provinces of China and find no evidence that the subsidies improved nutrition. In fact, it may have had a negative impact for some households.


Childhood Obesity and Unhappiness: The Influence of Soft Drinks and Fast Food Consumption

Hung-Hao Chang & Rodolfo Nayga
Journal of Happiness Studies, June 2010, Pages 261-275

A growing body of literature has examined the determinants of childhood obesity, but little is known about children's subjective wellbeing. To fulfill this gap, this paper examines the effects of fast food and soft drink consumption on children's overweight and unhappiness. Using a nationwide survey data in Taiwan and estimating a simultaneous mixed equation system, our results generally suggest a tradeoff in policy implication. Fast food and soft drink consumption tend to be positively associated with children's increased risk of being overweight but they are also negatively associated with their degree of unhappiness. Current and future policy/program interventions that aim to decrease fast food and soft drinks consumption of children to reduce childhood obesity may be more effective if these interventions also focus on ways that could compensate the increase in degree of unhappiness among children.


Estimating the Effects of Wages on Obesity

DaeHwan Kim & John Paul Leigh
Journal of Occupational and Environmental Medicine, May 2010, Pages 495-500

Objectives: To estimate the effects of wages on obesity and body mass.

Methods: Data on household heads, aged 20 to 65 years, with full-time jobs, were drawn from the Panel Study of Income Dynamics for 2003 to 2007. The Panel Study of Income Dynamics is a nationally representative sample. Instrumental variables (IV) for wages were created using knowledge of computer software and state legal minimum wages. Least squares (linear regression) with corrected standard errors were used to estimate the equations.

Results: Statistical tests revealed both instruments were strong and tests for over-identifying restrictions were favorable. Wages were found to be predictive (P < 0.05) of obesity and body mass in regressions both before and after applying IVs. Coefficient estimates suggested stronger effects in the IV models.

Conclusion: Results are consistent with the hypothesis that low wages increase obesity prevalence and body mass.


The effects of the National School Lunch Program on education and health

Peter Hinrichs
Journal of Policy Analysis and Management, Summer 2010, Pages 479-505

This paper estimates the effects of participating in the National School Lunch Program in the middle of the 20th century on adult health outcomes and educational attainment. I utilize an instrumental variables strategy that exploits a change in the formula used by the federal government to allocate funding to the states. Identification is achieved by the fact that different birth cohorts were exposed to different degrees to the original formula and the new formula, along with the fact that the change of the formula affected states differentially by per capita income. Participation in the program as a child appears to have few long-run effects on health, but the effects on educational attainment are sizable. These results may suggest that subsidized lunches induced children to attend school but displaced food consumption from other sources. Alternatively, the program may have had short-run health effects that dissipated over time but that facilitated higher educational attainment.


Does the Brain Consume Additional Glucose During Self-Control Tasks?

Robert Kurzban
Evolutionary Psychology, June 2010, Pages 244-259

A currently popular model of self-control posits that the exertion of self-control relies on a resource, which is expended by acts of self-control, resulting in less of this resource being available for subsequent acts of self-control. Recently, glucose has been proposed as the resource in question. For this model to be correct, it must be the case that A) performing a self-control task reduces glucose levels relative to a control task and B) performing a self-control task reduces glucose relative to pre-task levels. Evidence from neurophysiology suggests that (A) is unlikely to be true, and the evidence surrounding (B) is mixed, and is unlikely to be true for subjects who have not recently fasted. From the standpoint of evolved function, glucose might better be thought of as an input to decision making systems rather than as a constraint on performance.


Positive Mood and Resistance to Temptation: The Interfering Influence of Elevated Arousal

Alexander Fedorikhin & Vanessa Patrick
Journal of Consumer Research, forthcoming

We investigate the interfering influence of elevated arousal on the impact of positive mood on resistance to temptation. Three studies demonstrate that when a temptation activates long-term health goals, baseline positive mood facilitates resistance to temptation in 1) the choice between two snack items, one of which is more unhealthy, sinful, and hard to resist (M&M's) than the other (grapes) and 2) the monitoring of consumption when the sinful option is chosen. However, this influence is attenuated when positive mood is accompanied by elevated arousal. We demonstrate that the cognitive depletion that accompanies elevated arousal interferes with the self-regulatory focus of positive mood, decreasing resistance to temptation.


The Evolution of the Baby Food Industry, 2000-2008

Viola Chen
Journal of Competition Law and Economics, June 2010, Pages 423-442

In 2000, the Federal Trade Commission (FTC) prevented the merger of the second and third largest baby food manufacturers in the United States. Since the blocked merger, the landscape of the baby food industry has evolved significantly. All of the major brands of jarred baby food have undergone changes in ownership. The relevant product market may have slightly broadened beyond jarred baby food. Market concentration has increased, although prices have not. Gerber increased its market share from 71-72 to 73-80 percent. Beech-Nut's market share slightly declined from 13 to 11-12 percent, whereas Heinz's former brand, Nature's Goodness, declined from 13 to 2 percent. With no substantial entry, only Gerber and Beech-Nut currently have double-digit market shares. Also, although the average price of baby food has fluctuated over the years, prices in 2008 were the same as prices in 2000, after adjusting for inflation and changes in the composition of consumption. In terms of pricing, the market does not appear to be much different in 2008 than it was in 2000.


Twin Study of Heritability of Eating Bread in Danish and Finnish Men and Women

Ann Hasselbalch et al.
Twin Research and Human Genetics, April 2010, Pages 163-167

Bread is an elementary part of the western diet, and especially rye bread is regarded as an important source of fibre. We investigated the heritability of eating bread in terms of choice of white and rye bread and use-frequency of bread in female and male twins in Denmark and Finland. The study cohorts included 575 Danish (age range 18-67 years) and 2009 Finnish (age range 22-27 years) adult twin pairs. Self-reported frequency of eating bread was obtained by food frequency questionnaires. Univariate models based on linear structural equations for twin data were used to estimate the relative magnitude of the additive genetic, shared environmental and individual environmental effects on bread eating frequency and choice of bread. The analysis of bread intake frequency demonstrated moderate heritability ranging from 37-40% in the Finnish cohort and 23-26% in the Danish cohort. The genetic influence on intake of white bread was moderate (24-31%), while the genetic influence on intake of rye bread was higher in men (41-45%) than in women (24-33%). Environmental influences shared by the twins were not significant. Consumption of bread as well as choice of bread is influenced by genetic predisposition. Environmental factors shared by the co-twins (e.g., childhood environment) seem to have no significant effects on bread consumption and preference in adulthood.


Does Relative Thinking Exist in Real-World Situations? A Field Experiment with Bagels and Cream Cheese

Ofer Azar
Economic Inquiry, forthcoming

Many experiments show that consumers consider relative price differences even when only absolute price differences are relevant from an economic perspective, a phenomenon that was denoted "relative thinking." These experiments, however, were conducted using hypothetical questions. To test whether the relative thinking bias also exists in real-world situations, a field experiment where subjects could purchase either a bagel or a bagel with cream cheese was conducted. The monetary addition for the cream cheese was kept constant ($0.20) in both treatments, but the bagel's price varied ($0.05 in one treatment and $0.30 in the other). Relative thinking then implies that more people should add the cream cheese when the bagel's price is higher, because the relative price increase for the cream cheese is then smaller. However, the results did not document any relative thinking - more people (in percentage of those who purchase) added the cream cheese when the bagel's price was lower (the difference between the treatments, however, was not statistically significant). A replication of the experiment as a hypothetical-scenario experiment did document relative thinking, suggesting that introduction of financial incentives might alleviate relative thinking.


Rapid Assimilation of External Objects Into the Body Schema

Thomas Carlson, George Alvarez, Daw-an Wu & Frans Verstraten
Psychological Science, forthcoming

When a warrior picks up a sword for battle, do sword and soldier become one? The notion of an extended sense of the body has been the topic of philosophical discussion for more than a century and more recently has been subjected to empirical tests by psychologists and neuroscientists. We used a unique afterimage paradigm to test if, and under what conditions, objects are integrated into an extended body sense. Our experiments provide empirical support for the notion that objects can be integrated into an extended sense of the body. Our findings further indicate that this extended body sense is highly plastic, quickly assimilating objects that are in physical contact with the observer. Finally, we show that this extended body sense is limited to first-order extensions, thus constraining how far one can extend oneself into the environment.


Body image and first sexual intercourse in late adolescence

Sara Vasilenko, Nilam Ram & Eva Lefkowitz
Journal of Adolescence, forthcoming

Sexual behavior is associated with body image, but the directionality of this association is unclear. This study used longitudinal data from a sample of previously abstinent college students (N = 100, 45% female, 49% European American, 26% Latino American, 25% African American) to test whether satisfaction with appearance changed after first intercourse. Male students were more satisfied with their appearance after first intercourse, whereas female students became slightly less satisfied with their appearance. These findings demonstrate that first intercourse can lead to changes in well-being, even if the transition takes place in late adolescence. In addition, they suggest that gendered cultural expectations regarding sexual behavior are associated with differing psychological outcomes for male and female adolescents.


Big Boys and Little Girls: Gender, Acculturation, and Weight among Young Children of Immigrants

Jennifer Van Hook & Elizabeth Baker
Journal of Health and Social Behavior, June 2010, Pages 200-214

Previous research fails to find a consistent association between obesity and acculturation for children. We theorize that social isolation shelters children of immigrants from the U.S. "obesiogenic" environment, but this protective effect is offset by immigrant parents' limited capacity to identify and manage this health risk in the United States. We further theorize that these factors affect boys more than girls. We use data from over 20,000 children in the Early Childhood Longitudinal Study Kindergarten Cohort and find that boys whose parents were raised outside the United States weighed more and gained weight faster than any other group. However, within this group, sons of low English-proficient parents gained weight more slowly than sons of English-proficient parents. The results thus suggest that two dimensions of low acculturation - foreign place of socialization and social isolation - affect children's weight gain in opposite directions and are more important for boys than girls.


Am I too fat to be a princess? Examining the effects of popular children's media on young girls' body image

Sharon Hayes & Stacey Tantleff-Dunn
British Journal of Developmental Psychology, June 2010, Pages 413-426

The current study investigated the effects of brief exposure to appearance-related media on young girls' body image. One hundred and twenty-one girls aged 3-6 years old participated. Results indicated that exposure did not affect body dissatisfaction or engagement in appearance-related play behaviours. This is the first empirical study to provide support for previous findings that suggest media exposure does not affect body image in young girls. In contrast to older populations, it is possible that young children may adopt the persona of attractive characters with whom they identify rather than comparing themselves to the characters. Although nearly all girls liked the way they looked, self-report data indicated that nearly one-third of the participants would change something about their physical appearance and nearly half of the girls worried about being fat. Exposure to appearance-related media did not exacerbate concerns.


Marketing muscular masculinity in Arnold: The education of a bodybuilder

Ellexis Boyle
Journal of Gender Studies, June 2010, Pages 153-166

This article examines Arnold Schwarzenegger's ability to cross the wide divide between bodybuilding subculture, 'an oddball sport' shunned for its homoerotic imagery, and mainstream culture where he has become a popular icon of muscular masculinity. Where no other bodybuilder before or following him has been so successful, I show that it was Schwarzenegger's ability to mould himself to popular discourses that was the secret to his success. It is revealed that he developed a hyper-heterosexual persona and peddled an image of himself as a self-made man that fitted with broader cultural notions about American manhood. It is further revealed that whiteness plays a role in his ability to market himself, where whiteness underpins notions of masculine physical perfection within bodybuilding as well as in broader cultural notions about the kinds of bodies that are fit for American citizenship.

By KEVIN LEWIS | 08:56:00 AM