Processed foods and food reward

Food addiction comorbid to mental disorders in adolescents: a nationwide survey and register-based study

PURPOSE

Adolescence is a high-risk period for development of addictive behavior. This may also apply to addiction-like eating of highly processed foods-commonly referred to as "food addiction". Adolescents with mental disorder may be at particularly elevated risk of developing food addiction as addiction often accompanies mental disorder. However, there are only few studies in adolescents investigating this potential comorbidity. Therefore, the primary aim of this study was to examine the food addiction symptom load, as measured by the dimensional Yale Food Addiction Scale for Children-version 2.0 (dYFAS-C 2.0), among adolescents with a clinically verified mental disorder.

METHOD

A total of 3529 adolescents aged 13-17 were drawn from the Danish Psychiatric Central Research Register, stratified on six major diagnostic categories of mental disorders; psychotic disorders, affective disorders, anxiety disorders, eating disorders, autism spectrum disorders, and attention deficit disorders. Via their parents, these adolescents were invited to participate in a web-based survey. Data on health and socioeconomic factors from the Danish registers were linked to both respondents and non-respondents, allowing for thorough attrition analysis and estimation of weighted dYFAS-C 2.0 scores.

RESULTS

A total of 423 adolescents participated in the survey (response rate 12.0%). The mean weighted dYFAS-C 2.0 total score was 13.9 (95% CI 12.6; 14.9) for the entire sample and varied substantially across the diagnostic categories being highest for those with psychotic disorder, mean 18.4 (95% CI 14.6; 14.9), and affective disorders, mean 19.4. (95% CI 16.3; 22.5). Furthermore, the dYFAS-C 2.0 total score was positively correlated with body mass index (BMI) (r = 0.33, p < 0.05).

CONCLUSION

Food addiction symptomatology seems to be prevalent among adolescents with mental disorder, particularly affective and psychotic disorders. As obesity is a tremendous problem in individuals with mental disorder further investigation of food addiction in young people with mental disorder is called for. This could potentially aid in the identification of potential transdiagnostic targets for prevention and treatment of obesity in this group.

LEVEL OF EVIDENCE

Level IV, Observational cross-sectional descriptive study combined with retrospective register data.

Food insecurity and ultra-processed food consumption: the modifying role of participation in the Supplemental Nutrition Assistance Program (SNAP)

BACKGROUND

Ultra-processed foods contribute to risks of obesity and cardiometabolic disease, and higher intakes have been observed in low-income populations in the United States. Consumption of ultra-processed foods may be particularly higher among individuals experiencing food insecurity and participating in the Supplemental Nutrition Assistance Program (SNAP).

OBJECTIVES

Using data from the 2007-2016 NHANES, we examined the associations between food insecurity, SNAP participation, and ultra-processed food consumption.

METHODS

The study population comprised 9190 adults, aged 20-65 y, with incomes ≤300% of the federal poverty level (FPL). Food insecurity was assessed using the Household Food Security Survey Module and SNAP participation over the past 12 mo was self-reported. Dietary intake was measured from two 24-h dietary recalls. Ultra-processed food consumption (percentage of total energy intake) was defined using the NOVA food classification system. Linear regression models were used to examine the associations between food insecurity, SNAP participation, and ultra-processed food consumption, adjusting for sociodemographic and health characteristics.

RESULTS

More severe food insecurity was associated with higher intakes of ultra-processed foods (P-trend = 0.003). The adjusted means of ultra-processed food intake ranged from 52.6% for adults with high food security to 55.7% for adults with very low food security. SNAP participation was also associated with higher intakes of ultra-processed foods (adjusted mean: 54.7%), compared with income-eligible participants (adjusted mean: 53.0%). Furthermore, the association between food insecurity and ultra-processed foods was modified by SNAP participation (P-interaction = 0.02). Among income-eligible nonparticipants and income-ineligible nonparticipants, more severe food insecurity was associated with higher consumption of ultra-processed foods. Among SNAP participants, the association between food insecurity and consumption of ultra-processed foods was nonsignificant.

CONCLUSION

In a nationally representative sample of adults, food insecurity and SNAP participation were both associated with higher levels of ultra-processed food consumption.

Nutrition research challenges for processed food and health

Existing highly processed food (HPF) classification systems show large differences in the impact of these foods on biochemical risk factors for disease. If public health nutrition is to consider the degree of food processing as an important element of the link between food and health, certain gaps in research must be acknowledged. Quantifying the food additive exposure derived from HPFs is a task made challenging by the lack of data available on the occurrence and concentration of additives in food and the degree to which the natural occurrence of additives in unprocessed foods confounds exposure estimates. The proposed role of HPFs in health outcomes could also be associated with altered nutrient profiles. Differences exist within and between HPF classification systems in this regard and there are conflicting data on the impact of controlling for nutrient intake. Furthermore, research is needed on how the sensory aspects of HPFs contribute to energy intake. Current data suggest that high energy intake rate may be the mechanism linking HPFs and increased energy intake. A high priority now is to clarify the basis of definitions used to categorize foods as highly processed and, in a constructive sense, to distinguish between the contributions of nutrients, additives and sensory properties to health.

Highly processed food intake and immediate and future emotions in everyday life

Increased consumption of highly processed foods may result in lower diet quality, and low diet quality is associated with elevated risk of cardiovascular disease, type 2 diabetes, and cancer. One mechanism driving highly processed food intake is the expectation that eating these foods will improve emotional experiences, particularly in individuals with elevated "highly processed food addiction" symptoms. However, experimental findings about the emotional experiences following highly processed food intake are mixed. Furthermore, prior studies have generally failed to capture the potentially prolonged emotional effects of eating highly processed foods and not tested for individual differences. The present study was a preregistered archival data analysis of an ambulatory electronic diary study that captured real-life emotions following highly processed food intake. Multilevel modeling was used to predict the effects of highly processed food intake on subsequent positive and negative emotions immediately, 1 h, and 3 h after consumption. Intake of sweet high-fat foods, fast foods, and non-alcoholic sugary drinks was associated with greater positive emotions immediately after eating, and sweet high-fat food intake remained associated with greater positive emotions 1 h later. Sweet high-fat food and non-alcoholic sugary drink intake were associated with fewer negative emotions 1 h after consumption, and the negative association between non-alcoholic sugary drink intake and negative emotions was stronger for those with elevated highly processed food addiction symptoms. Overall, results suggest that highly processed food intake results in small alterations in positive and negative emotions immediately and up to 1 h after intake; however, these do not persist through 3 h after intake. The ability of highly processed foods to briefly alter emotions may be key to their reinforcing nature.

Sensory-Related Industrial Additives in the US Packaged Food Supply

Background: Increasing evidence suggests that ultra-processed foods (UPFs) lead to elevated risk of obesity-related conditions, but UPF measurement has been criticized for its subjectivity and lack of clarity on biological mechanism. Sensory-related industrial additives (SRIAs) are a defining feature of UPFs and may encourage overconsumption by enhancing the sensory quality of foods. However, practical challenges have prevented systematic incorporation of SRIAs into UPF measurement.

Objective: The objectives of this work were to describe a new, open-source ingredient list search method and to apply this method to describe the presence of SRIAs in US packaged foods.

Methods: We developed computer coding to search for 64 common SRIAs related to sweetness, flavor, appearance, and texture in 241,688 foods in the US Branded Food Products Database (BFPD). The BFPD includes manufacturer-provided ingredient lists for ~300,000 branded and private label food items. We determined the total number of SRIAs (0–64) and the number of different types of SRIAs (sweetness, flavor, appearance, texture, 0–4) in each food, then calculated the percent of all foods with SRIAs. This was done for all foods, and by food group for 224,098 items with food group data.

Results: Most (64.9%) foods in the BFPD contained at least one SRIA, and more than a third had at least three. Sweets (89.5%), beverages (84.9%), and ready-to-eat (RTE) foods (82.0%) were the most likely to contain SRIAs. With respect to SRIA types, 25.7% of all food items had at least three of the four types of SRIAs examined, with texture-related additives being the most common. Among sweets, 20% had all four types of SRIAs.

Discussion: This work confirms the high prevalence of SRIAs in US packaged foods. They are ubiquitous in sweets, beverages, and RTE foods, but also present in substantial proportions of other food groups. Quantifying the presence of SRIAs in ingredient lists offers a novel way to identify UPFs for research; to distinguish more vs. less ultra-processed foods; and to test whether UPFs increase risk for obesity-related conditions through additives that enhance the product's sensory qualities.

Linking drug and food addiction via compulsive appetite

BACKGROUND AND PURPOSE

"Food addiction" is the subject of intense public and research interest. However, this nosology based on neurobehavioral similarities among obese individuals and patients with eating disorders and drug addiction remains controversial. We thus sought to determine which aspects of disordered eating are causally linked to preclinical models of drug addiction. We hypothesized that extensive drug histories, known to cause addiction-like brain changes and drug motivation in rats, would also cause addiction-like food motivation.

EXPERIMENTAL APPROACH

Rats underwent extensive cocaine, alcohol, caffeine or obesogenic diet histories, and were subsequently tested for punishment-resistant food self-administration or "compulsive appetite", as a measure of addiction-like food motivation.

KEY RESULTS

Extensive cocaine and alcohol (but not caffeine) histories caused compulsive appetite that persisted long after the last drug exposure. Extensive obesogenic diet histories also caused compulsive appetite, although neither cocaine nor alcohol histories caused excess calorie intake and bodyweight during abstinence. Hence, compulsive appetite and obesity appear to be dissociable, with the former sharing common mechanisms with preclinical drug addiction models.

CONCLUSION AND IMPLICATIONS

Compulsive appetite, as seen in subsets of obese individuals and patients with binge-eating disorder and bulimia nervosa (eating disorders that do not necessarily result in obesity), appears to epitomize "food addiction". Because different drug and obesogenic diet histories caused compulsive appetite, overlapping dysregulations in the reward circuits, which control drug and food motivation independently of energy homeostasis, may offer common therapeutic targets for treating addictive behaviors across drug addiction, eating disorders and obesity.

Conceptualizing and Measuring Appetite Self-Regulation Phenotypes and Trajectories in Childhood: A Review of Person-Centered Strategies

This review uses person-centered research and data analysis strategies to discuss the conceptualization and measurement of appetite self-regulation (ASR) phenotypes and trajectories in childhood (from infancy to about ages 6 or 7 years). Research that is person-centered provides strategies that increase the possibilities for investigating ASR phenotypes. We first examine the utility of examining underlying phenotypes using latent profile/class analysis drawing on cross-sectional data. The use of trajectory analysis to investigate developmental change is then discussed, with attention to phenotypes using trajectories of individual behaviors as well as phenotypes based on multi-trajectory modeling. Data analysis strategies and measurement approaches from recent examples of these person-centered approaches to the conceptualization and investigation of appetite self-regulation and its development in childhood are examined. Where relevant, examples from older children as well as developmental, clinical and educational psychology are drawn on to discuss when and how person-centered approaches can be used. We argue that there is scope to incorporate recent advances in biological and psychoneurological knowledge about appetite self-regulation as well as fundamental processes in the development of general self-regulation to enhance the examination of phenotypes and their trajectories across childhood (and beyond). The discussion and conclusion suggest directions for future research and highlight the potential of person-centered approaches to progress knowledge about the development of appetite self-regulation in childhood.

Transdiagnostic Perspective of Impulsivity and Compulsivity in Obesity: From Cognitive Profile to Self-Reported Dimensions in Clinical Samples with and without Diabetes

Impulsive and compulsive behaviors have both been observed in individuals with obesity. The co-occurrence of obesity and type 2 diabetes (T2D) is more strongly associated with impulsivity, although there are no conclusive results yet. A multidimensional assessment of impulsivity and compulsivity was conducted in individuals with obesity in the absence or presence of T2D, compared with healthy, normal-weight individuals, with highly impulsive patients (gambling disorders), and with highly compulsive patients (anorexia nervosa). Decision making and novelty seeking were used to measure impulsivity, and cognitive flexibility and harm avoidance were used for compulsivity. For impulsivity, patients with obesity and T2D showed poorer decision-making ability compared with healthy individuals. For compulsivity, individuals with only obesity presented less cognitive flexibility and high harm avoidance; these dimensions were not associated with obesity with T2D. This study contributes to the knowledge of the mechanisms associated with diabetes and its association with impulsive–compulsive behaviors, confirming the hypothesis that patients with obesity and T2D would be characterized by higher levels of impulsivity.

Eliminate or reformulate ultra-processed foods? Biological mechanisms matter

Increased ultra-processed foods (UPFs) in the food supply have plausibly caused the rise in obesity prevalence and related chronic diseases. To address this public health concern, policies targeting reformulation or elimination of UPF categories will require improved understanding of the biological mechanisms whereby UPFs lead to overconsumption and poor health.

Validation of the dimensional Yale Food Addiction Scale for Children 2.0 and estimation of the weighted food addiction score in a sample of adolescents from the general population

PURPOSE

Obesity among adolescents is becoming increasingly prevalent and "food addiction" (addiction-like attraction to foods with high content of fat and refined carbohydrates) may be a potential contributor to this development. This study aimed to investigate the psychometric properties of the dimensional Yale Food Addiction Scale for Children version 2.0 (dYFAS-C 2.0) and to estimate the weighted mean score on the dYFAS-C 2.0 (as a measure of food addiction symptom load) among adolescents from the general Danish population.

METHODS

A total of 3,750 adolescents aged 13-17 were randomly drawn from the general Danish population and invited to participate in a web-based survey. Data on health and socioeconomic factors from the Danish registers were linked to both respondents and non-respondents, which allowed for analysis of attrition. The total- and sex-stratified weighted mean dYFAS-C 2.0 scores were estimated using augmented inverse probability weighted estimation.

RESULTS

A total of n = 576 (15.4%) adolescents participated in survey of whom 55.6% were female. The confirmatory factor analysis of the dYFAS-C 2.0 supported a one-factor model. The dYFAS-C 2.0 total score was associated with eating pathology, BMI z-scores, and ADHD symptomatology. The weighted mean dYFAS-C 2.0 score was 12.1 (95% CI: 11.2;12.9), 15.0 (95% CI: 13.9;16.2) for females and 9.5 (95% CI: 8.3;10.6) for males.

CONCLUSIONS

The dYFAS-C 2.0 appears to be a psychometrically valid tool to assess symptoms of food addiction among adolescents. Food addiction symptom severity correlated positively with eating pathology (including restrained eating), BMI z-scores, and ADHD symptomatology. Level IV, observational cross-sectional descriptive study combined with retrospective register data.

Brain response to food odors is not associated with body mass index and obesity-related metabolic health measures

Smell perception plays a role in eating behavior and might be involved in the development of obesity. In fact, olfactory function is impaired in obesity and might depend on metabolic health factors. To date, the underlying neural mechanisms remain unclear. Here, we investigate neural processing of food-related odors in normal-weight, overweight and obese individuals. Fifty-three young and healthy participants (28.8 ± 4.4 years, 27 female; 24 normal-weight, 10 overweight, and 19 obese) were presented with high- (chocolate, potato chips) and low-caloric (orange, cucumber) food odors during a functional magnetic resonance imaging (fMRI). We also assessed olfactory identification ability, body mass index (BMI), body fat percentage, insulin resistance, and leptin levels. In brief, olfactory perception of food odors was linked to brain activity in the entorhinal and piriform cortex, and the insula, hippocampus, and amygdala. Insulin resistance was negatively related to olfactory identification. Additionally, perception of sweet versus savory odors was related to a higher brain activity in the right middle/superior frontal gyrus. Finally, we found no effect of obesity status, BMI, metabolic factors, or body fat percentage on neural responses to food odors. Overall, this suggests that food odor processing might depend on factors other than body weight status or associated markers of metabolic health.

Trends in Consumption of Ultraprocessed Foods Among US Youths Aged 2-19 Years, 1999-2018

Importance

The childhood obesity rate has been steadily rising among US youths during the past 2 decades. Increasing evidence links consumption of ultraprocessed foods to excessive calorie consumption and weight gain, but trends in the consumption of ultraprocessed foods among US youths have not been well characterized.

Objective

To characterize trends in the consumption of ultraprocessed foods among US youths.

Design, Setting, and Participants

Serial cross-sectional analysis using 24-hour dietary recall data from a nationally representative sample of US youths aged 2-19 years (n = 33 795) from 10 cycles of the National Health and Nutrition Examination Survey (NHANES) from 1999-2000 to 2017-2018.

Exposures

Secular time.

Main Outcomes and Measures

Percentage of total energy consumed from ultraprocessed foods as defined by NOVA, an established food classification system that categorizes food according to the degree of food processing.

Results

Dietary intake from youths were analyzed (weighted mean age, 10.7 years; 49.1% were girls). From 1999 to 2018, the estimated percentage of total energy from consumption of ultraprocessed foods increased from 61.4% to 67.0% (difference, 5.6% [95% CI, 3.5% to 7.7%]; P < .001 for trend), whereas the percentage of total energy from consumption of unprocessed or minimally processed foods decreased from 28.8% to 23.5% (difference, -5.3% [95% CI, -7.5% to -3.2%]; P < .001 for trend). Among the subgroups of ultraprocessed foods, the estimated percentage of energy from consumption of ready-to-heat and -eat mixed dishes increased from 2.2% to 11.2% (difference, 8.9% [95% CI, 7.7% to 10.2%]) and from consumption of sweet snacks and sweets increased from 10.7% to 12.9% (difference, 2.3% [95% CI, 1.0% to 3.6%]), but the estimated percentage of energy decreased for sugar-sweetened beverages from 10.8% to 5.3% (difference, -5.5% [95% CI, -6.5% to -4.5%]) and for processed fats and oils, condiments, and sauces from 7.1% to 4.0% (difference, -3.1% [95% CI, -3.7% to -2.6%]) (all P < .05 for trend). There was a significantly larger increase in the estimated percentage of energy from consumption of ultraprocessed foods among non-Hispanic Black youths (from 62.2% to 72.5%; difference, 10.3% [95% CI, 6.8% to 13.8%]) and Mexican American youths (from 55.8% to 63.5%; difference, 7.6% [95% CI, 4.4% to 10.9%]) than the increase among non-Hispanic White youths (from 63.4% to 68.6%; difference, 5.2% [95% CI, 2.1% to 8.3%]) (P = .04 for trends).

Conclusions and Relevance

Based on the NHANES cycles from 1999 to 2018, the estimated proportion of energy intake from consumption of ultraprocessed foods has increased among youths in the US and has consistently comprised the majority of their total energy intake.

Age-Related Cognitive Decline May Be Moderated by Frequency of Specific Food Products Consumption

Our study aimed to evaluate whether the type of food products and the frequency of their consumption are associated with cognitive functioning in younger and older adults. The impact of diets that are high in added sugars and saturated fat on cognitive functioning, especially on memory, was at the center of our interest. Participants in the study were 204 healthy adults (aged 20-55) who performed a multitasking cognitive test and completed dietary and psychological questionnaires. Stepwise regression analysis with age and food consumption patterns as predictors, and the cognitive task performance as a dependent variable, revealed that cognitive task performance worsened with age. However, we found that the frequency of consuming different types of foods (healthy versus unhealthy dietary patterns) moderates the effects of age on cognitive functioning. Red meat and animal fat consumption were negatively correlated with cognitive performance, and this relation was dependent on the age of our participants. Conversely, white meat and fish consumption were positively related to memory. Different indices of dietary patterns (both positive and negative) were stronger predictors of cognitive performance in the older adult group. We interpret our results as evidence that diet may be a protective (or worsening) factor in age-related cognitive decline.

Food reinforcement and habituation to food are processes related to initiation and cessation of eating

An individual bout of eating involves cues to start eating, as well as cues to terminate eating. One process that determines initiation of eating is food reinforcement. Foods with high reinforcing value are also likely to be consumed in greater quantities. Research suggests both cross-sectional and prospective relationships between food reinforcement and obesity, food reinforcement is positively related to energy intake, and energy intake mediates the relationship between food reinforcement and obesity. A process related to cessation of eating is habituation. Habituation is a general behavioral process that describes a reduction in physiological or affective response to a stimulus, or a reduction in the behavioral responding to obtain a stimulus. Repeated exposure to the same food during a meal can result in habituation to that food and a reduction in consumption. Habituation is also cross-sectionally and prospectively related to body weight, as people who habituate slower consume more in a meal and are more overweight. Research from our laboratory has shown that these two processes independently influence eating, as they can account for almost 60% of the variance in ad libitum intake. In addition, habituation phenotypes show reliable relationships with reinforcing value, such that people who habituate faster also find food less reinforcing. Developing a better understanding of cues to start and stop eating is fundamental to understanding how to modify eating behavior. An overview of research on food reinforcement, habituation and food intake for people with a range of weight status and without eating disorders is provided, and ideas about integrating these two processes that are related to initiation and termination of a bout of eating are discussed.

Reconsolidation of a post-ingestive nutrient memory requires mTOR in the central amygdala

The central control of feeding behavior and metabolic homeostasis has been proposed to involve a form of post-ingestive nutrient learning independent of the gustatory value of food. However, after such learning, it is unknown which brain regions or circuits are activated to retrieve the stored memory and whether this memory undergoes reconsolidation that depends on protein synthesis after its reactivation through retrieval. In the present study, using a conditioned-flavor-preference paradigm by associating flavors with intra-gastric infusion of glucose to minimize the evaluation of the taste of food, we show that retrieval of the post-ingestive nutrient-conditioned flavor memory stimulates multiple brain regions in mice, including the central nucleus of the amygdala (CeA). Moreover, memory retrieval activated the mammalian target of rapamycin complex 1 (mTORC1) in the CeA, while site-specific or systemic inhibition of mTORC1 immediately after retrieval prevented the subsequent expression of the post-ingestive nutrient-associated flavor memory, leading to a long-lasting suppression of reinstatement. Taken together, our findings suggest that the reconsolidation process of a post-ingestive nutrient memory modulates food preferences.

Is Food Addictive? A Review of the Science

As ultraprocessed foods (i.e., foods composed of mostly cheap industrial sources of dietary energy and nutrients plus additives) have become more abundant in our food supply, rates of obesity and diet-related disease have increased simultaneously. Food addiction has emerged as a phenotype of significant empirical interest within the past decade, conceptualized most commonly as a substance-based addiction to ultraprocessed foods. We detail (a) how approaches used to understand substance-use disorders may be applicable for operationalizing food addiction, (b) evidence for the reinforcing potential of ingredients in ultraprocessed foods that may drive compulsive consumptions, (c) the utility of conceptualizing food addiction as a substance-use disorder versus a behavioral addiction, and (d) clinical and policy implications that may follow if ultraprocessed foods exhibit an addictive potential. Broadly, the existing literature suggests biological and behavioral parallels between food addiction and substance addictions, with ultraprocessed foods high in both added fat and refined carbohydrates being most implicated in addictive-like eating. Future research priorities are also discussed, including the need for longitudinal studies and the potential negative impact of addictive ultraprocessed foods on children. Expected final online publication date for the Annual Review of Nutrition, Volume 41 is September 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Nutritional Inadequacies Among Post-bariatric Patients During COVID-19 Quarantine in Sao Paulo, Brazil

Post bariatric control of food intake is influenced by psychological and behavioral factors. We investigated dietary habits and food intake during COVID-19 quarantine among recently operated patients. Patients were assessed for total and per meal energy and macronutrient intake as well as frequency of food consumption per processing level. Patients were also classified according to adherence to nutritional recommendations from our outpatient clinic. Main results are indicative of inappropriate nutritional intake during COVID-19 quarantine in postoperative bariatric patients. We observed that many patients failed to meet the recommended protein intake (89.2%) along a relatively high intake of ultra-processed foods (~1/4 of the diet). Our data suggest the need for the implementation of strategies to extend nutritional care to at-risk patients during social distancing.

Obesity: Overview of Weight Management

INTRODUCTION

Obesity is a chronic illness that requires a multifaceted personalized treatment approach.

METHODS & FINDINGS

Using current guidelines and recent studies in weight management, this article reviews the multiple components of weight management: lifestyle intervention (dietary intervention, physical activity, and behavioral interventions), pharmacotherapy, endoscopic procedures, and surgical procedures. This review briefly discusses specific diets and dietary strategies, compensatory mechanisms acting against weight loss, recent changes to Food and Drug Administration approved antiobesity medications, and technological advances in weight management delivery.

CONCLUSION

Current literature is lacking large studies on the safety and efficacy of combination therapies involving pharmacotherapy plus 1 or more procedures.

Fat and Carbohydrate Interact to Potentiate Food Reward in Healthy Weight but Not in Overweight or Obesity

Prior work suggests that actual, but not estimated, energy density drives the reinforcing value of food and that energy from fat and carbohydrate can interact to potentiate reward. Here we sought to replicate these findings in an American sample and to determine if the effects are influenced by body mass index (BMI). Thirty participants with healthy weight (HW; BMI 21.92 ± 1.77; M ± SD) and 30 participants with overweight/obesity (OW/OB; BMI 29.42 ± 4.44) rated pictures of common American snacks in 120-kcal portions for liking, familiarity, frequency of consumption, expected satiety, healthiness, energy content, energy density, and price. Participants then completed an auction task where they bid for the opportunity to consume each food. Snacks contained either primarily carbohydrate, primarily fat, or roughly equal portions of fat and carbohydrate (combo). Replicating prior work, we found that participants with HW bid the most for combo foods in linear mixed model analyses. This effect was not observed among individuals with OW/OB. Additionally, in contrast with previous reports, our linear regression analyses revealed a negative relationship between the actual energy density of the snacks and bid amount that was mediated by food price. Our findings support altered macronutrient reinforcement in obesity and highlight potential influences of the food environment on the regulation of food reward.

A narrative review of highly processed food addiction across the lifespan

Evidence is growing that highly processed (HP) foods (i.e., foods high in refined carbohydrates and fat) are highly effective in activating reward systems and may even be capable of triggering addictive processes. Unlike traditional drugs of abuse, exposure to HP foods is common very early in development. HP food addiction has been associated with negative outcomes, including higher body mass index (BMI), more frequent binge eating, greater failure in weight loss treatment trials, and poorer mental and physical health. Although most research on HP food addiction has been conducted using adult samples, research on this topic now spans across the life span beginning in utero and extending through older adulthood. HP food addiction and related reward-based changes are associated with negative outcomes at every life stage, which has important implications for developmentally tailored prevention and treatment efforts. Using a developmentally informed approach, the current study comprehensively reviews the existing research on HP food addiction across the lifespan and highlights important areas of future research.

Appetite self-regulation declines across childhood while general self-regulation improves: A narrative review of the origins and development of appetite self-regulation

This narrative review discusses the origins and development of appetite self-regulation (ASR) in childhood (from infancy to age 6 or 7 years). The origins, or foundations, are the biological infrastructure associated with appetite regulation and appetite self-regulation. Homeostatic regulation in infancy is examined and then evidence about developmental change in components of ASR. The main ASR-related components covered are: delay-of-gratification, caloric compensation, eating in the absence of hunger, food responsiveness/hedonics and fussy eating. The research included behavioral measures, parent-reports of appetitive traits and fMRI studies. There were two main trends in the evidence: a decline across childhood in the components of ASR associated with food approach (and therefore an increase in disinhibited eating), and wide individual differences. The decline in ASR contrasts with general self-regulation (GSR) where the evidence is of an improvement across childhood. For many children, bottom-up automatic reactive processes via food reward/hedonics or food avoidance as in fussy eating, appear not to be matched by improvements in top-down regulatory capacities. The prominence of bottom-up processes in ASR could be the main factor in possible differences in developmental paths for GSR and ASR. GSR research is situated in developmental science with its focus on developmental processes, theory and methodology. In contrast, the development of ASR at present does not have a strong developmental tradition to access and there is no unifying model of ASR and its development. We concluded (1) outside of mean-level or normative changes in the components of ASR, individual differences are prominent, and (2) there is a need to formulate models of developmental change in ASR together with appropriate measurement, research designs and data analysis strategies.

The concept of "food addiction" helps inform the understanding of overeating and obesity: YES

Addictive substances such as opiates and other drugs are highly reinforcing and some (but not all) individuals consume them compulsively. Highly processed (HP) foods have unnaturally high concentrations of refined carbohydrates and fat. These foods are highly reinforcing and some (but not all) individuals consume them compulsively. HP foods, like addictive substances, are more effective in activating reward-related neural systems than minimally processed foods. More importantly, HP foods are associated with the behavioral indicators of addiction: diminished control over consumption, strong craving, continued use despite negative consequences, and repeated failed attempts to reduce or eliminate intake. Thus, HP foods are key in addictive patterns of food intake. Like addictive drugs, HP foods are complex, human-made substances designed to effectively deliver reinforcing ingredients (e.g., refined carbohydrates, fat). Withdrawal and tolerance are not necessary for an addiction classification; however, HP foods can trigger both these processes. On a public health level, the negative consequences of HP foods are high, even for those without clinically relevant levels of addictive eating. The recognition that some foods can be addictive will inform clinical obesity treatment and underscore the importance of environmentally focused policy interventions.

The concept of "food addiction" helps inform the understanding of overeating and obesity: NO

Overeating is a complex behavioral phenotype in terms of both physiology and psychology. The mere transference of the diagnostic criteria for substance use disorders to define food addiction is too simplistic, for the following reasons: 1) a range of somatic and mental disorders require exclusion; 2) food addiction requires distinction from the physiological need to ingest sufficient calories to maintain a high body weight; 3) intentional weight loss can induce an eating behavior mimicking food addiction; 4) the concept lacks validation, especially in light of the high prevalence of "food addiction" in patients with anorexia nervosa; and 5) this construct has not led to novel and successful treatments for overeating and obesity. The concept of food addiction has the potential to distract from the need for focus on environmental influencers to combat the obesity pandemic.

Glucose and fat sensing in the human hypothalamus

Energy balance is centrally regulated by the brain through several interacting neuronal systems involving external, peripheral, and central factors within the brain. The hypothalamus integrates these factors and is the key brain area in the regulation of energy balance. In this review, we will explain the structure of the hypothalamus and its role in the regulation of energy balance. An important part of energy balance regulation is the sensing of nutrient status and availability. This review will focus on the sensing of the two main sources of energy by the hypothalamus: glucose and fat. As many common health problems and chronic diseases can be traced back to a disrupted hypothalamic function, we will also discuss hypothalamic sensing of glucose and fats in these pathologies. Finally, we will summarize the current knowledge and discuss how this may be applied clinically and for future research perspectives.

A rational review on the effects of sweeteners and sweetness enhancers on appetite, food reward and metabolic/adiposity outcomes in adults

Numerous strategies have been investigated to overcome the excessive weight gain that accompanies a chronic positive energy balance. Most approaches focus on a reduction of energy intake and the improvement of lifestyle habits. The use of high intensity artificial sweeteners, also known as non-caloric sweeteners (NCS), as sugar substitutes in foods and beverages, is rapidly developing. NCS are commonly defined as molecules with a sweetness profile of 30 times higher or more that of sucrose, scarcely contributing to the individual's net energy intake as they are hardly metabolized. The purpose of this review is first, to assess the impact of NCS on eating behaviour, including subjective appetite, food intake, food reward and sensory stimulation; and secondly, to assess the metabolic impact of NCS on body weight regulation, glucose homeostasis and gut health. The evidence reviewed suggests that while some sweeteners have the potential to increase subjective appetite, these effects do not translate in changes in food intake. This is supported by a large body of empirical evidence advocating that the use of NCS facilitates weight management when used alongside other weight management strategies. On the other hand, although NCS are very unlikely to impair insulin metabolism and glycaemic control, some studies suggest that NCS could have putatively undesirable effects, through various indirect mechanisms, on body weight, glycemia, adipogenesis and the gut microbiota; however there is insufficient evidence to determine the degree of such effects. Overall, the available data suggests that NCS can be used to facilitate a reduction in dietary energy content without significant negative effects on food intake behaviour or body metabolism, which would support their potential role in the prevention of obesity as a complementary strategy to other weight management approaches. More research is needed to determine the impact of NCS on metabolic health, in particular gut microbiota.

Ultra-processed food consumption and obesity in the Australian adult population

Background

Rapid simultaneous increases in ultra-processed food sales and obesity prevalence have been observed worldwide, including in Australia. Consumption of ultra-processed foods by the Australian population was previously shown to be systematically associated with increased risk of intakes of nutrients outside levels recommended for the prevention of obesity. This study aims to explore the association between ultra-processed food consumption and obesity among the Australian adult population and stratifying by age group, sex and physical activity level.

Methods

A cross-sectional analysis of anthropometric and dietary data from 7411 Australians aged ≥20 years from the National Nutrition and Physical Activity Survey 2011–2012 was performed. Food consumption was evaluated through 24-h recall. The NOVA system was used to identify ultra-processed foods, i.e. industrial formulations manufactured from substances derived from foods and typically added of flavours, colours and other cosmetic additives, such as soft drinks, confectionery, sweet or savoury packaged snacks, microwaveable frozen meals and fast food dishes. Measured weight, height and waist circumference (WC) data were used to calculate the body mass index (BMI) and diagnosis of obesity and abdominal obesity. Regression models were used to evaluate the association of dietary share of ultra-processed foods (quintiles) and obesity indicators, adjusting for socio-demographic variables, physical activity and smoking.

Results

Significant (P-trend ≤ 0.001) direct dose–response associations between the dietary share of ultra-processed foods and indicators of obesity were found after adjustment. In the multivariable regression analysis, those in the highest quintile of ultra-processed food consumption had significantly higher BMI (0.97 kg/m²; 95% CI 0.42, 1.51) and WC (1.92 cm; 95% CI 0.57, 3.27) and higher odds of having obesity (OR = 1.61; 95% CI 1.27, 2.04) and abdominal obesity (OR = 1.38; 95% CI 1.10, 1.72) compared with those in the lowest quintile of consumption. Subgroup analyses showed that the trend towards positive associations for all obesity indicators remained in all age groups, sex and physical activity level.

Conclusion

The findings add to the growing evidence that ultra-processed food consumption is associated with obesity and support the potential role of ultra-processed foods in contributing to obesity in Australia.

Ultra-processed foods and the nutrition transition: Global, regional and national trends, food systems transformations and political economy drivers

Understanding the drivers and dynamics of global ultra-processed food (UPF) consumption is essential, given the evidence linking these foods with adverse health outcomes. In this synthesis review, we take two steps. First, we quantify per capita volumes and trends in UPF sales, and ingredients (sweeteners, fats, sodium and cosmetic additives) supplied by these foods, in countries classified by income and region. Second, we review the literature on food systems and political economy factors that likely explain the observed changes. We find evidence for a substantial expansion in the types and quantities of UPFs sold worldwide, representing a transition towards a more processed global diet but with wide variations between regions and countries. As countries grow richer, higher volumes and a wider variety of UPFs are sold. Sales are highest in Australasia, North America, Europe and Latin America but growing rapidly in Asia, the Middle East and Africa. These developments are closely linked with the industrialization of food systems, technological change and globalization, including growth in the market and political activities of transnational food corporations and inadequate policies to protect nutrition in these new contexts. The scale of dietary change underway, especially in highly populated middle-income countries, raises serious concern for global health.

Development of MacroPics: A novel food picture set to dissociate the effects of carbohydrate and fat on eating behaviors

Emerging evidence suggests that fat and carbohydrate interact to potentiate the reward value of food (DiFeliceantonio et al., 2018). The primary goal of the current study was to develop a novel picture set to facilitate research into the effects of macronutrient composition on food choice and eating behavior. Toward this aim, we developed "MacroPics." In Experiment 1, we photographed 120-kcal portions of 60 snack foods falling into one of the three macronutrient categories: (1) mostly carbohydrate, (2) mostly fat, or (3) a combination of fat and carbohydrate. Sixty-one participants rated the images for liking, familiarity, frequency of consumption, healthiness, estimated energy content (in kcal), and expected satiation. A subset of these images consisting of 36 items was then selected in an iterative process to minimize differences in ratings between the macronutrient categories while simultaneously ensuring similar within-category variability on a number of food characteristics (e.g., energy density, portion size, retail price) and visual properties (e.g., color, complexity, visual area). In Experiment 2, an independent sample of 67 participants rated the pictures of the final 36-item MacroPics. Both experiments reveal similar participant ratings across categories for item liking, familiarity, frequency, healthiness, and estimated energy content. Protein content was higher in the fat compared to the carbohydrate and combination categories, leading to higher ratings of estimated satiety and energy density for fatty foods. Item and macronutrient category characteristics of the final MacroPics set are reported.

Pregnant Women Consume a Similar Proportion of Highly vs Minimally Processed Foods in the Absence of Hunger, Leading to Large Differences in Energy Intake

BACKGROUND

The eating in the absence of hunger (EAH) experimental paradigm measures intake of highly palatable, highly processed foods when sated. However, no studies have examined EAH in pregnant women.

OBJECTIVE

The objectives were to investigate whether EAH in pregnant women differs by level of food processing and to examine relationships of EAH with hedonic hunger, addictive-like eating, and impulsivity.

DESIGN

EAH was assessed in a counterbalanced crossover feeding substudy in which participants completed two free-access eating occasions following a standardized meal during their second pregnancy trimester. Hedonic hunger (Power of Food Scale), addictive-like eating (modified Yale Food Addiction Scale), and impulsivity (Barratt Impulsiveness Scale-15) were assessed by self-report during early pregnancy.

PARTICIPANTS AND SETTING

Data were collected from March 2015 through September 2016 from a subsample of participants (n = 46) enrolled at ≤12 weeks gestation in an observational, prospective cohort study (the Pregnancy Eating Attributes Study) in North Carolina.

INTERVENTION

Participants were presented with highly processed and minimally processed foods in two separate assessments.

MAIN OUTCOME MEASURES

Energy intake (EAH-kcal) and percent consumed (EAH-%) (calculated as 100 × [amount consumed (g) / amount served (g)]) was measured overall and separately for sweet and savory foods.

STATISTICAL ANALYSES PERFORMED

Linear mixed models estimated the effect of condition on EAH. Hedonic hunger, addictive-like eating, impulsivity and their interaction were examined separately.

RESULTS

EAH-% was similar across conditions (16.3% ± 1.1% highly processed vs 17.9% ± 1.2% minimally processed; P = 0.76), resulting in 338.5 ± 34.2 kcal greater energy intake in the highly processed vs minimally processed condition (P < 0.001). Hedonic hunger was not significantly associated with EAH; reward-related eating was positively associated with EAH-kcal and EAH-% of savory foods, and Barratt Impulsivity was positively associated with EAH-kcal and EAH-% overall, and with EAH-% of sweet foods (P < 0.05). There was little evidence of an interaction of Barratt Impulsivity with hedonic hunger or reward-related eating.

CONCLUSIONS

EAH in pregnant women occurs for both highly processed and minimally processed foods and correlates positively with self-reported addictive-like eating, but not hedonic hunger. Impulsivity did not modify associations of addictive-like eating with EAH in this sample.

The Aetiology of Olfactory Dysfunction and Its Relationship to Diet Quality

People with olfactory loss may choose foods rich in sugar, salt and fat to compensate their loss—foods that constitute a Western-style diet (WSD). However, olfactory dysfunction has not been consistently linked to any particular type of dietary change. Here we considered whether the aetiology of olfactory dysfunction may affect consumption of a WSD. Two-hundred and twenty-two people with olfactory dysfunction of varying cause, were tested for chemosensory performance and their frequency of consumption of a WSD. There was no evidence of a link between a WSD and olfactory dysfunction at the aggregate level, but an aetiology-based approach revealed various patterns, showing both positive and negative associations between olfactory performance and consumption of a WSD. We suggest a number of reasons why, in certain cases, greater olfactory dysfunction may be linked to lower intakes of a WSD, and the role that different aetiologies may have in affecting choices for foods that may appeal following olfactory impairment.

Low carbohydrate ketogenic therapy as a metabolic treatment for binge eating and ultraprocessed food addiction

PURPOSE OF REVIEW

The aim of this study was to highlight the recent advancements and future directions for potential use of a low carbohydrate ketogenic dietary approach to treat binge eating and ultraprocessed food addiction. Herein, we explore proposed mechanisms of why a diet low in refined carbohydrates, processed sugar and higher fat content may be helpful in alleviating symptoms.

RECENT FINDINGS

Emerging evidence suggests there may be a metabolic role in development of maladaptive eating. These findings broaden our understanding of eating psychopathology causes. Ultraprocessed, refined or high glycemic index carbohydrates are a possible trigger mediating neurochemical responses similar to addiction. The carbohydrate-insulin model of obesity supports observations of these foods triggering abnormal blood sugar and insulin spikes subsequently leading to changes in metabolic and neurobiological signaling. This results in overeating symptoms and hunger exacerbation, which differs from observed effects of healthy fat consumption and lack of similar insulin spikes. As supported in recent case series, significantly reducing or abstaining from these addictive-like ultraprocessed foods and highly refined carbohydrates could be considered a treatment approach.

SUMMARY

The current review highlights recent and pertinent evidence with respect to theoretical and practical application of low carbohydrate ketogenic therapeutic approaches for ultraprocessed food addiction and binge eating symptoms. VIDEO ABSTRACT:.

Separating the Signal from the Noise: How Psychiatric Diagnoses Can Help Discern Food Addiction from Dietary Restraint

Converging evidence from both animal and human studies have implicated hedonic eating as a driver of both binge eating and obesity. The construct of food addiction has been used to capture pathological eating across clinical and non-clinical populations. There is an ongoing debate regarding the value of a food addiction "diagnosis" among those with eating disorders such as anorexia nervosa binge/purge-type, bulimia nervosa, and binge eating disorder. Much of the food addiction research in eating disorder populations has failed to account for dietary restraint, which can increase addiction-like eating behaviors and may even lead to false positives. Some have argued that the concept of food addiction does more harm than good by encouraging restrictive approaches to eating. Others have shown that a better understanding of the food addiction model can reduce stigma associated with obesity. What is lacking in the literature is a description of a more comprehensive approach to the assessment of food addiction. This should include consideration of dietary restraint, and the presence of symptoms of other psychiatric disorders (substance use, posttraumatic stress, depressive, anxiety, attention deficit hyperactivity) to guide treatments including nutrition interventions. The purpose of this review is to help clinicians identify the symptoms of food addiction (true positives, or "the signal") from the more classic eating pathology (true negatives, or "restraint") that can potentially elevate food addiction scores (false positives, or "the noise"). Three clinical vignettes are presented, designed to aid with the assessment process, case conceptualization, and treatment strategies. The review summarizes logical steps that clinicians can take to contextualize elevated food addiction scores, even when the use of validated research instruments is not practical.

Ultra-processed food consumption, appetitive traits and BMI in children: a prospective study

This study aimed to investigate the association of ultra-processed food consumption at 4 and 7 years of age with appetitive traits at 7 years and BMI at 10 years of age. Participants were 1175 children of the population-based birth cohort Generation XXI, who provided food diaries and complete data on socio-demographic variables, anthropometric measures and the Portuguese Children's Eating Behaviour Questionnaire (P-CEBQ). Foods were grouped according to NOVA classification into: 'unprocessed, minimally or moderately processed, and culinary preparations'; 'processed' and 'ultra-processed'. To assess tracking of groups' consumption, Pearson's correlation coefficient (r) and the intraclass correlation coefficient (ICC) were calculated. Generalised linear models were fitted to test main associations, mediators and interactions among the variables. Ultra-processed consumption exhibited a fair level of stability between ages 4 and 7 years (r 0·34; ICC = 0·32; 95 % CI 0·25, 0·39), corresponding, respectively, to 27·3 % (1881·9 (SD 908·8) kJ/d) and 29·3 % (2204·5 (SD 961·1) kJ/d) of total energy intake. After adjusting for maternal and child characteristics, higher ultra-processed consumption at 4 years was associated directly with 'Food Responsiveness' (β = 0·019; 95 % CI 0·007, 0·037) and indirectly through energy intake with avoidant traits: 'Food Fussiness' (β = -0·007; 95 % CI 0·002, 0·012) and 'Satiety Responsiveness' (β = -0·007; 95 % CI 0·003, 0·012). Ultra-processed consumption at 4 years old was associated with BMI at 10 years old, but appetitive behaviours were not powerful mediators of this association. The results suggest a path by which ultra-processed products may impact on later appetitive traits and higher BMI in children.

Ultra-processed foods and binge eating: A retrospective observational study

OBJECTIVES

There is increasing evidence of the impact of ultra-processed foods on multiple metabolic and neurobiological pathways, including those involved in eating behaviors, both in animals and in humans. In this study we aimed to explore ultra-processed foods and their link with disordered eating in a clinical sample.

METHODS

This was a single site, retrospective observational study in a specialist eating disorder service using self-report on the electronic health records. Patients with a Diagnostic and Statistical Manual of Mental Disorders (fifth edition) diagnosis of anorexia nervosa (AN), bulimia nervosa (BN), or binge eating disorder (BED) were randomly selected from the service database in Oxford from 2017 to 2019. The recently introduced NOVA classification was used to determine the degree of industrial food processing in each patient's diet. Frequencies of ultra-processed foods were analyzed for each diagnosis at each mealtime and during episodes of binging.

RESULTS

A total of 70 female and 3 male patients were included in the study; 22 had AN, 25 BN, and 26 BED. Patients with AN reported consuming 55% NOVA-4 foods, as opposed to approximately 70% in BN and BED patients. Foods that were consumed in a binge pattern were 100% ultra-processed.

CONCLUSION

Further research into the metabolic and neurobiological effects of ultra-processed food intake on disordered eating, particularly on binging, is needed.

The Western diet: a blind spot of eating disorder research?-a narrative review and recommendations for treatment and research

Over the last 50 years, in parallel with the obesity epidemic, the prevalence of eating disorders has increased and presentations have changed. In this narrative review, we consider recent research exploring the implications of changing patterns of food consumption on metabolic and neurobiological pathways, a hitherto neglected area in eating disorder research. One of the major changes over this time has been the introduction of ultra-processed (NOVA-4) foods, which are gradually replacing unprocessed and minimally processed foods. This has resulted in the increased intake of various sugars and food additives worldwide, which has important metabolic consequences: triggering insulin and glucose response, stimulating appetite, and affecting multiple endocrine and neurobiological pathways, as well as the microbiome. A paradigm shift is needed in the conceptual framework by which the vulnerability to, and maintenance of, different eating disorders may be understood, by integrating recent knowledge of the individual metabolic responses to modern highly processed foods into existing psychological models. This could stimulate research and improve treatment outcomes.

Ultra-Processed Foods and Health Outcomes: A Narrative Review

The nutrition literature and authoritative reports increasingly recognise the concept of ultra-processed foods (UPF), as a descriptor of unhealthy diets. UPFs are now prevalent in diets worldwide. This review aims to identify and appraise the studies on healthy participants that investigated associations between levels of UPF consumption and health outcomes. This involved a systematic search for extant literature; integration and interpretation of findings from diverse study types, populations, health outcomes and dietary assessments; and quality appraisal. Of 43 studies reviewed, 37 found dietary UPF exposure associated with at least one adverse health outcome. Among adults, these included overweight, obesity and cardio-metabolic risks; cancer, type-2 diabetes and cardiovascular diseases; irritable bowel syndrome, depression and frailty conditions; and all-cause mortality. Among children and adolescents, these included cardio-metabolic risks and asthma. No study reported an association between UPF and beneficial health outcomes. Most findings were derived from observational studies and evidence of plausible biological mechanisms to increase confidence in the veracity of these observed associations is steadily evolving. There is now a considerable body of evidence supporting the use of UPFs as a scientific concept to assess the 'healthiness' of foods within the context of dietary patterns and to help inform the development of dietary guidelines and nutrition policy actions.

"Food" and "non-food" self-regulation in childhood: a review and reciprocal analysis

BACKGROUND

In developmental science, there is an extensive literature on non-food related self-regulation in childhood, where several domains relating to emotions, actions and cognitions have been identified. There is now growing attention to food related self-regulation in childhood, especially difficulties with ASR, and the consequences for weight gain and adiposity. The aim of this narrative review was to conduct a reciprocal analysis of self-regulation in the food and non-food domains in childhood (referred to as appetite self-regulation (ASR) and general self-regulation (GSR) respectively). The focus was on commonalities and differences in key concepts and underpinning processes.

METHODS

Databases and major journals were searched using terms such as self-regulation, appetite self-regulation, or self-regulation of energy intake, together with associated constructs (e.g., Executive Function, Effortful Control, delay-of-gratification). This was followed by backward and forward snowballing.

RESULTS AND DISCUSSION

The scholarship on GSR in childhood has had a focus on the role of the cognitively-oriented Executive Function (EF), the temperamentally-based Effortful Control (EC) and the recursive interplay between bottom-up (reactive, emotion driven, approach or avoidance) and top-down (cognitive, conscious decision-making) processes. "Hot" and "cool/cold" EF and self-regulation situations have been distinguished. There were some parallels between GSR and ASR in these areas, but uncertainty about the contribution of EF and EC to ASR in young children. Possible differences between the contribution to ASR-related outcomes of delay-of-gratification in food and non-food tasks were apparent. Unique elements of ASR were identified; associated with psychological, biological and neurological responses to food and bottom-up processes. A diverse number of situations or elements connected to ASR exist: for example, energy balance homeostasis, caloric compensation, hunger regulation, satiation, satiety, energy density of food, eating in the absence of hunger, emotional eating, etc. CONCLUSIONS: Self-regulation in food and non-food domains are amenable to a reciprocal analysis. We argue that self-regulation of appetite should be added as a domain under the umbrella of self-regulation in childhood along with the other non-food related domains. This could lead to a broader understanding of self-regulation in childhood, and generate novel lines of enquiry.

Choice is relative: Reinforcing value of food and activity in obesity treatment

Persons with obesity find high-energy-dense food and sedentary behaviors highly reinforcing. Diets and exercise programs deprive individuals of many favorite foods and activities, which can counterproductively heighten their value and lead to relapse. Since the value of reinforcers depend on the alternatives available, one approach to reducing food and sedentary activity reinforcement is to build healthy alternative reinforcers. Current behavioral treatment programs for children and adults do not attempt to build alternative reinforcers as substitutes for unhealthy behaviors to reduce the impact of food or activity deprivation on the motivation to eat or be inactive. A goal of the next generation of obesity treatment programs should focus on development of healthy behaviors as reinforcers so that people will be motivated to engage in them. This article provides an overview of relationships among reinforcers, how understanding substitutes and complements can influence eating and activity, and how enriching a person's environment and providing choice architecture can enhance weight control. Ideas for translation of these basic behavioral economic principles to obesity treatment programs are discussed. (PsycINFO Database Record (c) 2020 APA, all rights reserved).

Rethinking Food Reward

The conscious perception of the hedonic sensory properties of caloric foods is commonly believed to guide our dietary choices. Current and traditional models implicate the consciously perceived hedonic qualities of food as driving overeating, whereas subliminal signals arising from the gut would curb our uncontrolled desire for calories. Here we review recent animal and human studies that support a markedly different model for food reward. These findings reveal in particular the existence of subcortical body-to-brain neural pathways linking gastrointestinal nutrient sensors to the brain's reward regions. Unexpectedly, consciously perceptible hedonic qualities appear to play a less relevant, and mostly transient, role in food reinforcement. In this model, gut-brain reward pathways bypass cranial taste and aroma sensory receptors and the cortical networks that give rise to flavor perception. They instead reinforce behaviors independently of the cognitive processes that support overt insights into the nature of our dietary decisions.

Non-invasive stimulation of vagal afferents reduces gastric frequency

Metabolic feedback between the gut and the brain relayed via the vagus nerve contributes to energy homeostasis. We investigated in healthy adults whether non-invasive stimulation of vagal afferents impacts energy homeostasis via efferent effects on metabolism or digestion. In a randomized crossover design, we applied transcutaneous auricular vagus nerve stimulation (taVNS) while recording efferent metabolic effects using simultaneous electrogastrography (EGG) and indirect calorimetry. We found that taVNS reduced gastric myoelectric frequency (p = .008), but did not alter resting energy expenditure. We conclude that stimulating vagal afferents induces gastric slowing via vagal efferents without acutely affecting net energy expenditure at rest. Collectively, this highlights the potential of taVNS to modulate digestion by activating the dorsal vagal complex. Thus, taVNS-induced changes in gastric frequency are an important peripheral marker of brain stimulation effects.

The Calorie and Nutrient Density of More- Versus Less-Processed Packaged Food and Beverage Products in the Canadian Food Supply

The association between the degree of processing and healthfulness of foods remains unclear. Most evidence of this relationship is based on dietary intake surveys rather than individual products and varies depending on the food processing classification system used. This study aimed to compare the nutritional quality of more- versus less-processed packaged foods and beverages in Canada, using a large, branded food database and two processing classification systems. Nutritional information for products (n = 17,269) was sourced from the University of Toronto FLIP 2017 database. Products were categorized using the NOVA and Poti et al. processing classification systems. Calories, sodium, saturated fat, total and free sugars, fibre and protein per 100 g (or mL) were examined by processing category using descriptive statistics and linear regression. Overall, the most-processed products under both systems were more likely to be lower in protein, and higher in total and free sugars, compared with less-processed foods (p < 0.05); the direction and strength of the association between other nutrients/components and level of processing were less consistent. These findings demonstrate that calorie- and nutrient-dense foods exist across different levels of processing, suggesting that food choices and dietary recommendations should be based primarily on energy or nutrient density rather than processing classification.