Neural correlates of food addiction

CONTEXT

Research has implicated an addictive process in the development and maintenance of obesity. Although parallels in neural functioning between obesity and substance dependence have been found, to our knowledge, no studies have examined the neural correlates of addictive-like eating behavior.

OBJECTIVE

To test the hypothesis that elevated "food addiction" scores are associated with similar patterns of neural activation as substance dependence.

DESIGN

Between-subjects functional magnetic resonance imaging study.

SETTING

A university neuroimaging center.

PARTICIPANTS

Forty-eight healthy young women ranging from lean to obese recruited for a healthy weight maintenance trial.

MAIN OUTCOME MEASURE

The relation between elevated food addiction scores and blood oxygen level-dependent functional magnetic resonance imaging activation in response to receipt and anticipated receipt of palatable food (chocolate milkshake).

RESULTS

Food addiction scores (N = 39) correlated with greater activation in the anterior cingulate cortex, medial orbitofrontal cortex, and amygdala in response to anticipated receipt of food (P < .05, false discovery rate corrected for multiple comparisons in small volumes). Participants with higher (n = 15) vs lower (n = 11) food addiction scores showed greater activation in the dorsolateral prefrontal cortex and the caudate in response to anticipated receipt of food but less activation in the lateral orbitofrontal cortex in response to receipt of food (false discovery rate-corrected P < .05).

CONCLUSIONS

Similar patterns of neural activation are implicated in addictive-like eating behavior and substance dependence: elevated activation in reward circuitry in response to food cues and reduced activation of inhibitory regions in response to food intake.

Advancing public health obesity policy through state attorneys general

Obesity in the United States exacts a heavy health and financial toll, requiring new approaches to address this public health crisis. State attorneys general have been underutilized in efforts to formulate and implement food and obesity policy solutions. Their authority lies at the intersection of law and public policy, creating unique opportunities unavailable to other officials and government entities. Attorneys general have a broad range of authority over matters specifically relevant to obesity and nutrition policy, including parens patriae (parent of the country) authority, protecting consumer interests, enacting and supporting rules and regulations, working together across states, engaging in consumer education, and drafting opinions and amicus briefs. Significant room exists for greater attorney general involvement in formulating and championing solutions to public health problems such as obesity.

Effects of serving high-sugar cereals on children's breakfast-eating behavior

OBJECTIVES

To test (1) whether children will consume low-sugar ready-to-eat (RTE) cereals and (2) the effects of serving high- versus low-sugar cereals on the consumption of cereal, refined sugar, fresh fruit, and milk.

PARTICIPANTS AND METHODS

Using an experimental design, we randomly assigned children (n = 91) who were attending summer day camp to receive a breakfast that included either the choice of 1 of 3 high-sugar cereals (high-sugar condition) or low-sugar cereals (low-sugar condition), as well as low-fat milk, orange juice, bananas, strawberries, and sugar packets. Participants served themselves and completed a background questionnaire after eating. Researchers measured the amount and calories consumed of each food.

RESULTS

In both conditions, children reported "liking" or "loving" the cereal they chose. Children in the low-sugar cereal condition consumed, on average, slightly more than 1 serving of cereal (35 g), whereas children in the high-sugar condition consumed significantly more (61 g) and almost twice the amount of refined sugar in total (24.4 vs 12.5 g). Milk and total calories consumed did not differ significantly between conditions, but children in the low-sugar condition were more likely to put fruit on their cereal (54% vs 8%) and consumed a greater portion of total calories from fresh fruit (20% vs 13%).

CONCLUSIONS

Compared with serving low-sugar cereals, high-sugar cereals increase children's total sugar consumption and reduce the overall nutritional quality of their breakfast. Children will consume low-sugar cereals when offered, and they provide a superior breakfast option.

Influence of licensed characters on children's taste and snack preferences

OBJECTIVE

The goal was to study how popular licensed cartoon characters appearing on food packaging affect young children's taste and snack preferences.

METHODS

Forty 4- to 6-year-old children tasted 3 pairs of identical foods (graham crackers, gummy fruit snacks, and carrots) presented in packages either with or without a popular cartoon character. Children tasted both food items in each pair and indicated whether the 2 foods tasted the same or one tasted better. Children then selected which of the food items they would prefer to eat for a snack.

RESULTS

Children significantly preferred the taste of foods that had popular cartoon characters on the packaging, compared with the same foods without characters. The majority of children selected the food sample with a licensed character on it for their snack, but the effects were weaker for carrots than for gummy fruit snacks and graham crackers.

CONCLUSIONS

Branding food packages with licensed characters substantially influences young children's taste preferences and snack selection and does so most strongly for energy-dense, nutrient-poor foods. These findings suggest that the use of licensed characters to advertise junk food to children should be restricted.

The impact of food prices on consumption: a systematic review of research on the price elasticity of demand for food

In light of proposals to improve diets by shifting food prices, it is important to understand how price changes affect demand for various foods. We reviewed 160 studies on the price elasticity of demand for major food categories to assess mean elasticities by food category and variations in estimates by study design. Price elasticities for foods and nonalcoholic beverages ranged from 0.27 to 0.81 (absolute values), with food away from home, soft drinks, juice, and meats being most responsive to price changes (0.7-0.8). As an example, a 10% increase in soft drink prices should reduce consumption by 8% to 10%. Studies estimating price effects on substitutions from unhealthy to healthy food and price responsiveness among at-risk populations are particularly needed.

The food industry and self-regulation: standards to promote success and to avoid public health failures

Threatened by possible government regulation and critical public opinion, industries often undertake self-regulatory actions, issue statements of concern for public welfare, and assert that self-regulation is sufficient to protect the public. The food industry has made highly visible pledges to curtail children's food marketing, sell fewer unhealthy products in schools, and label foods in responsible ways. Ceding regulation to industry carries opportunities but is highly risky. In some industries (e.g., tobacco), self-regulation has been an abject failure, but in others (e.g., forestry and marine fisheries), it has been more successful. We examined food industry self-regulation in the context of other self-regulatory successes and failures and defined 8 standards that should be met if self-regulation is to be effective.

Evaluating the impact of menu labeling on food choices and intake

OBJECTIVES

We assessed the impact of restaurant menu calorie labels on food choices and intake.

METHODS

Participants in a study dinner (n=303) were randomly assigned to either (1) a menu without calorie labels (no calorie labels), (2) a menu with calorie labels (calorie labels), or (3) a menu with calorie labels and a label stating the recommended daily caloric intake for an average adult (calorie labels plus information). Food choices and intake during and after the study dinner were measured.

RESULTS

Participants in both calorie label conditions ordered fewer calories than those in the no calorie labels condition. When calorie label conditions were combined, that group consumed 14% fewer calories than the no calorie labels group. Individuals in the calorie labels condition consumed more calories after the study dinner than those in both other conditions. When calories consumed during and after the study dinner were combined, participants in the calorie labels plus information group consumed an average of 250 fewer calories than those in the other groups.

CONCLUSIONS

Calorie labels on restaurant menus impacted food choices and intake; adding a recommended daily caloric requirement label increased this effect, suggesting menu label legislation should require such a label. Future research should evaluate menu labeling's impact on children's food choices and consumption.

Methodological issues in weight cycling

Recent studies have suggested that weight changes may be related to disease risk independent of weight status. A critical step in testing this assertion is the measurement of weight change and so-called "weight cycling". However intuitive the concept of weight cycling may appear, research in this area is hampered by complex methodological issues. This article discusses various measures of nominal weight cycling, including the standard deviation, coefficient of variation, regression techniques, and cycles. A cycle is a sequence of a gain followed by a loss or vice versa. The various measures are compared in seven hypothetical cases created to illustrate their strengths and weaknesses. Superior performance of the cycles measure over the coefficient of variation, number of fluctuations, and simple regression methods is argued. The linkage of the cycles measure with the statistical theory of runs also provides a basis for testing the significance of weight fluctuations or other variables that may cycle, such as blood lipids, etc. The cycles measure and runs test provide a viable definition for identifying weight cycling and a tool for evaluating the critical amount of weight gained and/or lost in relationship to risk.

Rationale and evidence for menu-labeling legislation

Menu-labeling legislation is a proposed public health intervention for poor diet and obesity that requires chain restaurants to provide nutrition information on menus and menu boards. The restaurant industry has strongly opposed menu-labeling legislation. Using scientific evidence, this paper counters industry arguments against menu labeling by demonstrating that consumers want chain restaurant nutrition information to be disclosed; the current methods of providing nutrition information are inadequate; the expense of providing nutrition information is minimal; the government has the legal right to mandate disclosure of information; consumers have the right to know nutrition information; a lack of information reduces the efficiency of a market economy; and menu labeling has the potential to make a positive public health impact.

The Food Marketing Defense Model: Integrating Psychological Research to Protect Youth and Inform Public Policy

Marketing practices that promote calorie-dense, nutrient-poor foods directly to children and adolescents present significant public health risk. Worldwide, calls for government action and industry change to protect young people from the negative effects of food marketing have increased. Current proposals focus on restricting television advertising to children under 12 years old, but current psychological models suggest that much more is required. All forms of marketing pose considerable risk; adolescents are also highly vulnerable; and food marketing may produce far-reaching negative health outcomes. We propose a food marketing defense model that posits four necessary conditions to effectively counter harmful food marketing practices: awareness, understanding, ability and motivation to resist. A new generation of psychological research is needed to examine each of these processes, including the psychological mechanisms through which food marketing affects young people, to identify public policy that will effectively protect them from harmful influence.

The need for bold action to prevent adolescent obesity

Record levels of obesity in children and adolescents are predictable in light of powerful conditions that promote high consumption of calorie-dense, nutrient-poor foods and discourage physical activity. Default conditions for youth are dangerous, and include multiple and relentless forms of marketing, poor foods promoted in schools, and a variety of other conditions that undermine personal resources, individual responsibility, and parental authority. This article discusses how optimal defaults can be created using five issues as examples: framing of the obesity issue, treating versus preventing obesity, nutrition in schools, marketing, and addressing weight bias and discrimination. By adopting a public health approach that addresses the conditions causing obesity, there is hope of reversing troubling trends in prevalence.

Priming effects of television food advertising on eating behavior

OBJECTIVE

Health advocates have focused on the prevalence of advertising for calorie-dense low-nutrient foods as a significant contributor to the obesity epidemic. This research tests the hypothesis that exposure to food advertising during TV viewing may also contribute to obesity by triggering automatic snacking of available food.

DESIGN

In Experiments 1a and 1b, elementary-school-age children watched a cartoon that contained either food advertising or advertising for other products and received a snack while watching. In Experiment 2, adults watched a TV program that included food advertising that promoted snacking and/or fun product benefits, food advertising that promoted nutrition benefits, or no food advertising. The adults then tasted and evaluated a range of healthy to unhealthy snack foods in an apparently separate experiment.

MAIN OUTCOME MEASURES

Amount of snack foods consumed during and after advertising exposure.

RESULTS

Children consumed 45% more when exposed to food advertising. Adults consumed more of both healthy and unhealthy snack foods following exposure to snack food advertising compared to the other conditions. In both experiments, food advertising increased consumption of products not in the presented advertisements, and these effects were not related to reported hunger or other conscious influences.

CONCLUSION

These experiments demonstrate the power of food advertising to prime automatic eating behaviors and thus influence far more than brand preference alone.

The relationship between eating disorder not otherwise specified (EDNOS) and officially recognized eating disorders: meta-analysis and implications for DSM

Eating disorder not otherwise specified (EDNOS) is the most prevalent eating disorder (ED) diagnosis. In this meta-analysis, the authors aimed to inform Diagnostic and Statistical Manual of Mental Disorders revisions by comparing the psychopathology of EDNOS with that of the officially recognized EDs: anorexia nervosa (AN), bulimia nervosa (BN), and binge eating disorder (BED). A comprehensive literature search identified 125 eligible studies (published and unpublished) appearing in the literature from 1987 to 2007. Random effects analyses indicated that whereas EDNOS did not differ significantly from AN and BED on eating pathology or general psychopathology, BN exhibited greater eating and general psychopathology than EDNOS. Moderator analyses indicated that EDNOS groups who met all diagnostic criteria for AN except for amenorrhea did not differ significantly from full syndrome cases. Similarly, EDNOS groups who met all criteria for BN or BED except for binge frequency did not differ significantly from full syndrome cases. Results suggest that EDNOS represents a set of disorders associated with substantial psychological and physiological morbidity. Although certain EDNOS subtypes could be incorporated into existing Diagnostic and Statistical Manual of Mental Disorders (4th ed.; American Psychiatric Association, 1994) categories, others-such as purging disorder and non-fat-phobic AN-may be best conceptualized as distinct syndromes. (PsycINFO Database Record (c) 2009 APA, all rights reserved).

Eighty-five per cent of what? Discrepancies in the weight cut-off for anorexia nervosa substantially affect the prevalence of underweight

BACKGROUND

DSM-IV cites <85% of expected body weight (EBW) as a guideline for the diagnosis of anorexia nervosa (AN) but does not require a specific method for calculating EBW. The purpose of the present study was to determine the degree to which weight cut-off calculations vary across studies, and to evaluate whether differential cut-offs lead to discrepancies in the prevalence of individuals who are eligible for the AN diagnosis.

METHOD

Two coders independently recorded the EBW calculation methods from 99 studies that either (a) compared individuals with AN to those with subclinical eating disorders or (b) conducted AN treatment trials. Each weight cut-off was applied to a nationally representative (n=12001) and treatment-seeking (n=189) sample to determine the impact of EBW calculation on the proportion who met the AN weight criterion.

RESULTS

Coders identified 10 different EBW methods, each of which produced different weight cut-offs for the diagnosis of AN. Although only 0.23% of the national sample met the lowest cut-off, this number increased 43-fold to 10.10% under the highest cut-off. Similarly, only 48.1% of treatment seekers met the lowest cut-off, whereas 89.4% met the highest.

CONCLUSIONS

There is considerable variance across studies in the determination of the AN weight cut-off. Discrepancies substantially affect the proportion of individuals who are eligible for diagnosis, treatment and insurance reimbursement. However, differences may not be fully appreciated because the ubiquitous citation of the 85% criterion creates a sense of false consensus.

The perils of ignoring history: Big Tobacco played dirty and millions died. How similar is Big Food?

CONTEXT

In 1954 the tobacco industry paid to publish the "Frank Statement to Cigarette Smokers" in hundreds of U.S. newspapers. It stated that the public's health was the industry's concern above all others and promised a variety of good-faith changes. What followed were decades of deceit and actions that cost millions of lives. In the hope that the food history will be written differently, this article both highlights important lessons that can be learned from the tobacco experience and recommends actions for the food industry.

METHODS

A review and analysis of empirical and historical evidence pertaining to tobacco and food industry practices, messages, and strategies to influence public opinion, legislation and regulation, litigation, and the conduct of science.

FINDINGS

The tobacco industry had a playbook, a script, that emphasized personal responsibility, paying scientists who delivered research that instilled doubt, criticizing the "junk" science that found harms associated with smoking, making self-regulatory pledges, lobbying with massive resources to stifle government action, introducing "safer" products, and simultaneously manipulating and denying both the addictive nature of their products and their marketing to children. The script of the food industry is both similar to and different from the tobacco industry script.

CONCLUSIONS

Food is obviously different from tobacco, and the food industry differs from tobacco companies in important ways, but there also are significant similarities in the actions that these industries have taken in response to concern that their products cause harm. Because obesity is now a major global problem, the world cannot afford a repeat of the tobacco history, in which industry talks about the moral high ground but does not occupy it.

Obesity metaphors: how beliefs about the causes of obesity affect support for public policy

CONTEXT

Relatively little is known about the factors shaping public attitudes toward obesity as a policy concern. This study examines whether individuals' beliefs about the causes of obesity affect their support for policies aimed at stemming obesity rates. This article identifies a unique role of metaphor-based beliefs, as distinct from conventional political attitudes, in explaining support for obesity policies.

METHODS

This article used the Yale Rudd Center Public Opinion on Obesity Survey, a nationally representative web sample surveyed from the Knowledge Networks panel in 2006/07 (N = 1,009). The study examines how respondents' demographic and health characteristics, political attitudes, and agreement with seven obesity metaphors affect support for sixteen policies to reduce obesity rates.

FINDINGS

Including obesity metaphors in regression models helps explain public support for policies to curb obesity beyond levels attributable solely to demographic, health, and political characteristics. The metaphors that people use to understand rising obesity rates are strong predictors of support for public policy, and their influence varies across different types of policy interventions.

CONCLUSIONS

Over the last five years, the United States has begun to grapple with the implications of dramatically escalating rates of obesity. Individuals use metaphors to better understand increasing rates of obesity, and obesity metaphors are independent and powerful predictors of support for public policies to curb obesity. Metaphorical reasoning also offers a potential framework for using strategic issue framing to shift support for obesity policies.

Innovative legal approaches to address obesity

CONTEXT

The law is a powerful public health tool with considerable potential to address the obesity issue. Scientific advances, gaps in the current regulatory environment, and new ways of conceptualizing rights and responsibilities offer a foundation for legal innovation.

METHODS

This article connects developments in public health and nutrition with legal advances to define promising avenues for preventing obesity through the application of the law.

FINDINGS

Two sets of approaches are defined: (1) direct application of the law to factors known to contribute to obesity and (2) original and innovative legal solutions that address the weak regulatory stance of government and the ineffectiveness of existing policies used to control obesity. Specific legal strategies are discussed for limiting children's food marketing, confronting the potential addictive properties of food, compelling industry speech, increasing government speech, regulating conduct, using tort litigation, applying nuisance law as a litigation strategy, and considering performance-based regulation as an alternative to typical regulatory actions. Finally, preemption is an overriding issue and can play both a facilitative and a hindering role in obesity policy.

CONCLUSIONS

Legal solutions are immediately available to the government to address obesity and should be considered at the federal, state, and local levels. New and innovative legal solutions represent opportunities to take the law in creative directions and to link legal, nutrition, and public health communities in constructive ways.

Considerations for an obesity policy research agenda

The rise in obesity levels in the U.S. in the past several decades has been dramatic, with serious implications for public health and the economy. Experiences in tobacco control and other public health initiatives have shown that public policy may be a powerful tool to effect structural change to alter population-level behavior. In 2007, the National Cancer Institute convened a meeting to discuss priorities for a research agenda to inform obesity policy. Issues considered were how to define obesity policy research, key challenges and key partners in formulating and implementing an obesity policy research agenda, criteria by which to set research priorities, and specific research needs and questions. Themes that emerged were: (1) the embryonic nature of obesity policy research, (2) the need to study "natural experiments" resulting from policy-based efforts to address the obesity epidemic, (3) the importance of research focused beyond individual-level behavior change, (4) the need for economic research across several relevant policy areas, and (5) the overall urgency of taking action in the policy arena. Moving forward, timely evaluation of natural experiments is of especially high priority. A variety of policies intended to promote healthy weight in children and adults are being implemented in communities and at the state and national levels. Although some of these policies are supported by the findings of intervention research, additional research is needed to evaluate the implementation and quantify the impact of new policies designed to address obesity.