Processed foods and food reward

Ultra-processed foods cause weight gain and increased energy intake associated with reduced chewing frequency: A randomized, open-label, crossover study

AIM

To elucidate the effects of ultra-processed foods (UPFs) on body weight and ad libitum energy intake compared with non-UPFs.

MATERIALS AND METHODS

In this randomized, open-label crossover study conducted at the University of Tokyo Hospital, overweight/obese Japanese male participants were randomly assigned (1:1) to start the study with consumption of either UPFs or non-UPFs for 1 week, followed by a 2-week washout period, before crossing over to the alternate food diet for 1 week. Individuals with diabetes, hypertension or any other medical conditions who visited a hospital regularly were excluded. The meals were designed to be matched for the total energy and macronutrient levels. The primary outcome was the difference in the body weight change between the UPF and non-UPF periods. The differences in the average daily energy intake and chewing frequency were assessed as one of the prespecified secondary outcomes.

RESULTS

Nine eligible participants were randomly assigned to start the study with either UPFs or non-UPFs. All participants completed the study. During the UPF period, participants gained 1.1 kg more weight (95% confidence interval 0.2 to 2.0; P = .021) and consumed 813.5 kcal more per day (342.4 to 1284.7; P = .0041) compared with during the non-UPF period. Regarding the chewing frequency, the number of chews per calorie was significantly lower during the UPF period (P = .016).

CONCLUSIONS

Consumption of UPFs causes significant weight gain. Medical nutritional therapy focused on reducing the consumption of UPFs could be an effective strategy for preventing obesity.

Self-reported food liking and wanting: A factor analytic study of ratings across 49 consecutive days

Reward responses to food are thought to play an important role in highly palatable food overconsumption. In animal models, food reward responses can be decoupled into unique "liking" (in the moment enjoyment) and "wanting" (motivation/craving) components. However, research on liking and wanting has been hampered by uncertainty regarding whether liking and wanting can be reliably separated in humans. We used factor analysis to test whether ratings of liking and wanting could be empirically separated in women assessed across 49 consecutive days. Female participants (N = 688; ages 15-30) from the Michigan State University Twin Registry reported liking and wanting of foods consumed that day, and wanting of foods not consumed that day, separately for sweets (e.g., cookies), fast food (e.g., French fries), carbohydrates (e.g., bread), and whole foods (fruit, plain chicken) each evening for 49 consecutive days. We examined both average levels and daily levels of liking/wanting across the 49-day period that captured individual differences in liking/wanting over time. Across both types of analyses, liking and wanting for foods that were eaten formed a single factor rather than separate, dissociable factors, while wanting of foods not eaten formed an independent factor. At the daily level, a liking/wanting factor emerged for each individual food category (e.g., liking/wanting sweets), whereas in average analyses, a single factor emerged that collapsed across all food types (i.e., liking/wanting of all foods). Results suggest individuals have difficulty distinguishing between liking and wanting of foods they have eaten on that day but may be able to more reliably separate wanting of foods they have not consumed.

The EAT-Lancet diet associated cardiovascular health parameters: evidence from a Brazilian study

BACKGROUND

The EAT-Lancet diet is a diet aimed at promoting population and planetary health from the perspective of sustainable diets in terms of environmental and health aspects. This study aimed to assess the association between adherence to the EAT-Lancet diet and cardiometabolic risk factors among adults and elderly individuals in a capital city in the northeastern region of Brazil.

METHODS

This is an analytical cross-sectional observational study from a population-based sample conducted between 2019 and 2020, involving 398 non-institutionalized adults and elderly people, of both sexes from "Brazilian Usual Consumption Assessment" study (Brazuca-Natal). There was a 38% response rate due to the suspension of data collection due to the covid-19 pandemic, but According to the comparative analysis of socioeconomic and demographic variables between the surveyed and non-surveyed sectors, losses were found to be random (p = 0.135, Little's MCAR test). Socioeconomic and lifestyle data, anthropometric measurements, and dietary consumption were collected. We used the Planetary Health Diet Index (PHDI) and the Cardiovascular Health Diet Index (CHDI) for cardiovascular health to assess adherence to the diet's sustainability. The evaluated cardiometabolic parameters included fasting blood glucose, triglycerides, total cholesterol, HDL-C, LDL-C, and systolic and diastolic blood pressure measurements. We also assessed the presence of type 2 diabetes mellitus, arterial hypertension, and dyslipidemia. For the data analyses, sample weights and the effect of the study design were taken into account. Pearson's chi-square test was used to evaluate the statistical significance of frequencies. Multiple linear regression models assessed the associations between PHDI and CHDI and its components and the cardiometabolic parameters.

RESULTS

The mean PHDI was 29.4 (95% CI 28.04:30.81), on a total score ranging from 0 to 150 points and the mean CHDI was 32.63 (95% CI 31.50:33.78), on a total score ranging from 0 to 110 points. PHDI showed a significant positive association with the final CHDI score and components of fruits, vegetables, and legumes, and a negative association with Ultra-processed Food (UPF) (p < 0.05). Notably, among the most consumed UPF, the following stand out: "packaged snacks, shoestring potatoes, and crackers" (16.94%), followed by margarine (14.14%). The PHDI exhibited a significant association with diabetes and dyslipidemia, as well as with systolic blood pressure, total cholesterol, and LDL-C.

CONCLUSIONS

The results suggest that adopting the EAT-Lancet diet is associated with the improvement of key cardiovascular health indicators.

Pupillary dilation response to the auditory food words in adolescents with obesity without binge eating disorder

Childhood obesity is a growing global public health problem. Studies suggest that environmental cues contribute to developing and maintaining obesity. We aimed to evaluate pupillary changes to auditory food words vs. nonfood words and to conduct a dynamic temporal analysis of pupil size changes in adolescents with obesity without binge eating disorder by comparing healthy-weight adolescents. In this study, a total of 63 adolescents aged 12-18 years (n = 32, obesity group (OG); n = 31, control group (CG)) were included. In an auditory paradigm, participants were presented with a series of high and low-calorie food and nonfood words. A binocular remote eye-tracking device was used to measure pupil diameter. Generalized additive mixed models (GAMMs) were used for dynamic temporal analysis of pupillometry data. The results of GAMM analysis indicated that CG had larger pupil dilation than the OG while listening to auditory food words. CG had larger pupil dilation in food words than in nonfood words. However, the OG had a similar pupillary response in food and nonfood words. Pupil dilation response to higher-calorie foods was extended over the later stages of the time period (after 2000 ms) in the OG. In summary, our findings indicated that individuals with obesity had lower pupil dilation to auditory food words compared to normal-weight peers. Adolescents with obesity had prolonged pupillary dilation in higher calories of food words. The individual psychological factors affecting the dynamic changes of pupil responses to food cues in adolescents with obesity should be examined in further studies.

Ultraprocessed food consumption and risk of gallstone disease: analysis of 3 prospective cohorts

BACKGROUND

Majority of dietary intake in United States adults comes from ultraprocessed foods (UPFs), which have been linked to several adverse health outcomes. Gallstone disease is highly prevalent and constitutes a significant burden to the United States health system but remains understudied.

OBJECTIVES

This study aimed to investigate the association between UPF consumption and incident gallstone disease risk.

METHODS

In this analysis, 44,149 males in the Health Professionals' Follow-up Study (HPFS: 1986-2022), 71,145 females in the Nurses' Health Study (NHS: 1986-2021), and 90,932 females in the NHS II (1991-2021) were prospectively followed. Dietary intake was quadrennially assessed with semiquantitative food frequency questionnaires and used to identify UPFs. The primary outcome was defined as cholecystectomy. Cox proportional hazards model was used to estimate adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs).

RESULTS

Baseline median age was 54 y in HPFS, 53 y in NHS, and 36 y in NHS II. We identified 32,374 incident gallstone disease cases over 5,077,059 person-years. Participants in the highest UPF quintile had a higher incidence of gallstone disease than those in the lowest quintile (aHR: 1.29; 95% CI: 1.24, 1.36; P < 0.001). Incremental risk of incident gallstone disease was 2.8% per daily serving (95% CI: 2.4%, 3.2%; P < 0.001). This risk was driven by sugar-sweetened beverages and artificially sweetened beverages on UPF subgroup analyses. The proportion of risk mediated by obesity was 12.8% (95% CI: 7.7%, 20.5%; P < 0.001) in HPFS, 14.3% (95% CI: 10.4%, 19.4%; P < 0.001) in NHS, and 39.4% (95% CI: 31.2%, 48.1%; P < 0.001) in NHS II. The partial population attributable risk was estimated at 15.9% (95% CI: 13.4%, 18.3%).

CONCLUSIONS

UPF consumption is associated with a higher risk of gallstone disease, particularly consumption of sugar-sweetened beverages and artificially sweetened beverages. A substantial proportion of this risk is potentially mediated by obesity in younger females.

Obesity- and diet-induced plasticity in systems that control eating and energy balance

In April 2023, the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), in partnership with the National Institute of Child Health and Human Development, the National Institute on Aging, and the Office of Behavioral and Social Sciences Research, hosted a 2-day online workshop to discuss neural plasticity in energy homeostasis and obesity. The goal was to provide a broad view of current knowledge while identifying research questions and challenges regarding neural systems that control food intake and energy balance. This review includes highlights from the meeting and is intended both to introduce unfamiliar audiences with concepts central to energy homeostasis, feeding, and obesity and to highlight up-and-coming research in these areas that may be of special interest to those with a background in these fields. The overarching theme of this review addresses plasticity within the central and peripheral nervous systems that regulates and influences eating, emphasizing distinctions between healthy and disease states. This is by no means a comprehensive review because this is a broad and rapidly developing area. However, we have pointed out relevant reviews and primary articles throughout, as well as gaps in current understanding and opportunities for developments in the field.

Isocaloric replacement of ultraprocessed foods was associated with greater weight loss in the POUNDS Lost trial

OBJECTIVE

Higher intake of ultraprocessed foods (UPFs) is associated with obesity. We examined whether replacing UPFs (NOVA 4) with minimally processed foods and culinary ingredients (NOVA 1 + 2) was associated with differential weight change in this secondary prospective analysis of the Preventing Overweight Using Novel Dietary Strategies (POUNDS) Lost trial.

METHODS

We estimated percent energy intake (%kcal) from the four NOVA groups using 24-h dietary recalls in a subset of 356 participants. Multivariable-adjusted substitution models examined whether replacing %kcal from UPFs with NOVA 1 + 2 was associated with greater weight, body fat percentage, trunk fat, and waist circumference reduction at 6 months; changes in parameters were compared among NOVA 1 + 2 tertiles (T).

RESULTS

Participants were on average 52.3 years of age, 85% White, 55% female, and 58.2% nonsmoking, with a mean BMI of 32.7 kg/m2. Replacing 10%kcal of UPFs with NOVA 1 + 2 was associated with greater 6-month weight (ß = 0.51, 95% CI: -0.93 to -0.09, p = 0.02), body fat percentage (ß = 2.7, 95% CI: -5.10 to -0.43, p = 0.02), and trunk fat reduction (ß = 3.9, 95% CI: -7.01 to -0.70, p = 0.02), but not waist circumference reduction. Participants in T3 (-8.33 kg) versus T1 (-5.32 kg) of NOVA 1 + 2 had greater weight loss (p < 0.001).

CONCLUSIONS

Isocaloric substitution of UPFs with NOVA 1 + 2 was associated with marginally greater weight loss under energy restriction. These modest findings support more research exploring the mechanisms linking UPFs with body weight regulation beyond energy intake.

Creation and validation of a NOVA scored picture set to evaluate ultra-processed foods

There has been a rapid shift in the modern food environment towards increased processing in foods consumed in the United States (US) and globally. The NOVA system (not an acronym) for classifying food on degree of processing currently has the most empirical support. Consumption of foods in the NOVA 4 category, ultra-processed foods (UPF), is a risk factor for a host of poor health outcomes including heart disease, stroke, and cancer. Despite these poor health outcomes, UPF make up 58% of calories consumed in the US. Methodologies for assessing the reinforcing and rewarding properties of these foods are necessary tools. The Becker-DeGroot-Marschak auction paradigm (BDM) is a well validated tool for measuring value and is amenable to neuromonitoring environments. To allow for the testing of hypotheses based on level of food processing, we present a picture set of 14 UPF and 14 minimally-processed foods (MPF) matched on visual properties, food characteristics (fat, carbohydrate, cost, etc.), and rated perceptual properties. Further, we report our scoring of these foods using the NOVA classification system and provide additional data from credentialed nutrition professionals and on inter-rater reliability using NOVA, a critique of the system. Finally, we provide all pictures, data, and code used to create this picture set as a tool for researchers.

Brain dopamine responses to ultra-processed milkshakes are highly variable and not significantly related to adiposity in humans

Ultra-processed foods high in fat and sugar may be addictive, in part, due to their purported ability to induce an exaggerated postingestive brain dopamine response akin to drugs of abuse. Using standard [11C]raclopride positron emission tomography (PET) displacement methods used to measure brain dopamine responses to addictive drugs, we measured postingestive striatal dopamine responses to an ultra-processed milkshake high in fat and sugar in 50 young, healthy adults over a wide body mass index range (BMI 20-45 kg/m2). Surprisingly, milkshake consumption did not result in significant postingestive dopamine response in the striatum (p=0.62) nor any striatal subregion (p>0.33) and the highly variable interindividual responses were not significantly related to adiposity (BMI: r=0.076, p=0.51; %body fat: r=0.16, p=0.28). Thus, postingestive striatal dopamine responses to an ultra-processed milkshake were likely substantially smaller than many addictive drugs and below the limits of detection using standard PET methods.

Association between ultra-processed food and snacking behavior in Brazil

PURPOSE

Ultra-processed food may play a role in facilitating snacking behavior because of their convenience and low satiety potential. This study aimed to describe the association between consumption of ultra-processed foods and frequency of snacking.

METHODS

We analyzed data from 46,164 participants (≥ 10 years old) in the 2017-2018 Brazilian Household Budget Survey. Dietary data were collected by 24-h dietary recalls over one or two days for each participant. We estimated energy intake, ultra-processed food consumption, and level of snacking. We measured the association between ultra-processed food consumption and level of snacking using multinomial logistic regression, stratified by age group (adolescents, 10-19 years old; adults, 20-64 years old; elders, 65 or older).

RESULTS

We found a statistically significant tendency of increased daily energy intake and consumption of snacks and that ultra-processed food consumption was positively associated with the level of snacking for all age groups. For adolescents, adults, and elders in the highest quintile of ultra-processed food consumption as a share of their entire diet, the relative risk ratio (95% CI) of having more than two snacks per day compared to no snacks was 14.21 (9.09-22.21), 4.44 (3.54-5.57), and 4.21 (2.67-6.64), respectively, when compared to the lowest quintile.

CONCLUSION

Higher consumption of ultra-processed food was associated with snacking behavior, and the strength of this association was stronger among adolescents. Efforts to mitigate ultra-processed food attributes that facilitate snacking should be incorporated into strategies to promote healthier food choices, especially among adolescents.

A psychobioecological model to understand the income-food insecurity-obesity relationship

Food insecurity, defined by unpredictable access to food that may not meet a person's nutritional needs, is associated with higher BMI (kg/m2) and obesity. People with food insecurity often have less access to food, miss meals and go hungry, which can lead to psychological and metabolic changes that favor energy conservation and weight gain. We describe a conceptual model that includes psychological (food reinforcement and delay discounting) and physiological (thermic effect of food and substrate oxidation) factors to understand how resource scarcity associated with food insecurity evolves into the food insecurity-obesity paradox. We present both animal and human translational research to describe how behavioral and metabolic adaptations to resource scarcity based on behavioral ecology theory may occur for people with food insecurity. We conclude with ideas for interventions to prevent or modify the behaviors and underlying physiology that characterize the income-food insecurity-obesity relationship.

The Italian food environment may confer protection from hyper-palatable foods: evidence and comparison with the United States

Background

Multi-national food corporations may saturate country-level food systems with hyper-palatable foods. However, the degree to which global food corporations have been integrated into country-level food systems may vary. Italy has largely retained local food production and may have low hyper-palatable food (HPF) availability in the food supply. The study quantified the prevalence of HPF in the Italian food system and compared the hyper-palatability of similar foods across Italy and the United States, which has wide HPF saturation.

Methods

A national food system dataset was used to characterize HPF availability in Italy. A representative sample of foods commonly consumed in both Italy and the US were collected and compared. Foods represented six categories: cookies/biscotti, cakes/merendine, salty snacks, industrial bread, frozen pizza and protein/cereal bars. A standardized definition from Fazzino et al. identified HPF.

Results

Less than one third (28.8%) of foods in the Italian food system were hyper-palatable. US HPF items had significantly higher fat, sugar, and/or sodium across most food categories (p values = 0.001 to 0.0001). Italian HPF items had higher fiber and/or protein relative to US HPF from the same category (p values = 0.01 to 0.0001).

Conclusion

The Italian food system may confer protection from HPF exposure. HPF products in Italy had lower palatability-related nutrients and higher satiety-promoting nutrients.

Ultra-processed Food and Obesity: What Is the Evidence?

PURPOSE OF REVIEW

Obesity is a growing global healthcare concern. A proposed driver is the recent increase in ultra-processed food (UPF) intake. However, disagreement surrounds the concept of UPF, the strength of evidence, and suggested mechanisms. Therefore, this review aimed to critically appraise the evidence on UPF and obesity.

RECENT FINDINGS

Observational studies demonstrate positive associations between UPF intake, weight gain, and overweight/obesity, more clearly in adults than children/adolescents. This is supported by high-quality clinical data. Several mechanisms are proposed, but current understanding is inconclusive. Greater UPF consumption has been a key driver of obesity. There is a need to change the obesogenic environment to support individuals to reduce their UPF intake. The UPF concept is a novel approach that is not explained with existing nutrient- and food-based frameworks. Critical analysis of methodologies provides confidence, but future observational and experimental research outputs with greater methodological rigor will strengthen findings, which are outlined.

Separate gut-brain circuits for fat and sugar reinforcement combine to promote overeating

Food is a powerful natural reinforcer that guides feeding decisions. The vagus nerve conveys internal sensory information from the gut to the brain about nutritional value; however, the cellular and molecular basis of macronutrient-specific reward circuits is poorly understood. Here, we monitor in vivo calcium dynamics to provide direct evidence of independent vagal sensing pathways for the detection of dietary fats and sugars. Using activity-dependent genetic capture of vagal neurons activated in response to gut infusions of nutrients, we demonstrate the existence of separate gut-brain circuits for fat and sugar sensing that are necessary and sufficient for nutrient-specific reinforcement. Even when controlling for calories, combined activation of fat and sugar circuits increases nigrostriatal dopamine release and overeating compared with fat or sugar alone. This work provides new insights into the complex sensory circuitry that mediates motivated behavior and suggests that a subconscious internal drive to consume obesogenic diets (e.g., those high in both fat and sugar) may impede conscious dieting efforts.

US tobacco companies selectively disseminated hyper-palatable foods into the US food system: Empirical evidence and current implications

BACKGROUND AND AIMS

US tobacco companies owned leading US food companies from 1980 to 2001. We measured whether hyper-palatable foods (HPF) were disproportionately developed in tobacco-owned food companies, resulting in substantial tobacco-related influence on the US food system.

DESIGN

The study involved a review of primary industry documents to identify food brands that were tobacco company-owned. Data sets from the US Department of Agriculture were integrated to facilitate longitudinal analyses estimating the degree to which foods were formulated to be hyper-palatable, based on tobacco ownership.

SETTING AND CASES

United States Department of Agriculture data sets were used to identify HPF foods that were (n = 105) and were not (n = 587) owned by US tobacco companies from 1988 to 2001.

MEASUREMENTS

A standardized definition from Fazzino et al. (2019) was used to identify HPF. HPF items were identified overall and by HPF group: fat and sodium HPF, fat and sugar HPF and carbohydrates and sodium HPF.

FINDINGS

Tobacco-owned foods were 29% more likely to be classified as fat and sodium HPF and 80% more likely to be classified as carbohydrate and sodium HPF than foods that were not tobacco-owned between 1988 and 2001 (P-values = 0.005-0.009). The availability of fat and sodium HPF (> 57%) and carbohydrate and sodium HPF (> 17%) was high in 2018 regardless of prior tobacco-ownership status, suggesting widespread saturation into the food system.

CONCLUSIONS

Tobacco companies appear to have selectively disseminated hyper-palatable foods into the US food system between 1988 and 2001.

Ultraprocessed, hyper-palatable, and high energy density foods: Prevalence and distinction across 30 years in the United States

OBJECTIVE

Ultraprocessed foods (UPF), hyper-palatable foods (HPF), and high energy density (HED) foods may contribute to obesity risk. All have distinct definitions; however, it is unknown the degree to which they may identify overlapping or distinct foods. This study examined the availability of UPF, HPF, and HED foods in the US food system from 1988 to 2018 and the degree of distinction across definitions.

METHODS

Four data sets representing the US food system (1988, 2001, 2006, 2018) from the US Department of Agriculture were analyzed. UPF were identified based on the extent of industrialized processing. HPF were identified using the standardized definition that specifies palatability-inducing nutrient combinations. HED was characterized as >2.0 kcal/g.

RESULTS

Across years, 58% to 65% of foods were classified as UPF, 55% to 69% as HPF, and 37% to 47% as HED. Prevalence of UPF, HPF, and HED foods was higher in 2018 versus 1988 (p values < 0.001); HPF evidenced the largest increase (14%) and UPF evidenced the smallest (4%) over time. There was moderate to high overlap in foods (40%-70%) across definitions.

CONCLUSIONS

Together, UPF, HPF, and HED foods comprise most foods in the US food supply. Changes in availability varied across definitions, with substantial increases in HPF and HED and relative stability of UPF.

Food Insecurity and Food Addiction in a Large, National Sample of Lower-Income Adults

Background

Growing research has highlighted associations between food insecurity and eating-related problems. Food addiction is one important, clinically significant pattern of problematic eating, which is related to, but distinct from, eating disorders. To date, there is only one study examining the association between food insecurity and food addiction, to our knowledge. Additional research is needed to understand the complexities of this association.

Objective

We examined the association between food insecurity and food addiction in a large, national convenience sample of lower-income adults and potential heterogeneity in this association by age, gender, race, and ethnicity.

Design

A cross-sectional, web-based study was conducted among 1780 US adults (≥18 y) with household incomes <250% of the federal poverty guideline. Household food security was assessed using the Household Food Security Survey Module. Food addiction was assessed using the modified Yale Food Addiction Scale (mYFAS), version 2.0. Multivariate logistic regression models examined the associations between food insecurity and food addiction, adjusting for sociodemographic covariates.

Results

The prevalence of food addiction was 7.3%, and the prevalence of food insecurity was 51%. Compared with adults with food security, adults with food insecurity endorsed each mYFAS symptom with significantly greater frequency, including failure to fulfill major role obligations (20%), continued use despite social or interpersonal problems (18%), and craving or strong desire to use (16%). After adjustment, food insecurity was associated with 3.82-fold higher odds of food addiction (95% CI 2.36, 6.19), with no significant heterogeneity by age, gender, or race and ethnicity. The most problematic foods reported by adults with food insecurity were chips, nondiet soda, chocolate, pizza, and ice cream.

Conclusion

These findings provide additional support for the association between food insecurity and food addiction. Mechanistic studies are needed to explore the role of psychosocial factors, eating behaviors, and the food environment in contributing to these associations.

Nutrition and Mental Well-Being: Exploring Connections and Holistic Approaches

Quality of life, well-being, and psycho-emotional balance are closely related to the quality of the diet, the level of physical activity, the quality of rest, but also the absence of the consumption of narcotic substances and tobacco, or alcohol abuse. Based on the distribution of a questionnaire that included 30 questions, we aimed to statistically evaluate several factors that influence mental health and vices. It recorded a total of 1719 valid responses, which came from 78.3% female respondents and 21.7% male respondents. After processing the anthropometric data, it was observed that the majority of respondents are of normal weight (63.87%) and come from women in particular (36.13%). Based on the answers recorded, although over 60% of the respondents participating in the study are up to 40 years old, there is an increased tendency towards sedentarism (over 58% of the respondents declaring that they do sports very rarely or not at all), a low tendency regarding optimal consumption of vegetables and fruits, many respondents do not hydrate properly, which is why approximately 60% of respondents feel frequently tired, and over 32% are frequently nervous. The increased level of stress among the respondents and emotional eating are also generated by inadequate rest, reduced physical activity, and a diet that does not help the efficient detoxification of the body.

Perspective: A Research Roadmap about Ultra-Processed Foods and Human Health for the United States Food System: Proceedings from an Interdisciplinary, Multi-Stakeholder Workshop

Our objective was to convene interdisciplinary experts from government, academia, and industry to develop a Research Roadmap to identify research priorities about processed food intake and risk for obesity and cardiometabolic diseases (CMD) among United States populations. We convened attendees at various career stages with diverse viewpoints in the field. We held a "Food Processing Primer" to build foundational knowledge of how and why foods are processed, followed by presentations about how processed foods may affect energy intake, obesity, and CMD risk. Breakout groups discussed potential mechanistic and confounding explanations for associations between processed foods and obesity and CMD risk. Facilitators created research questions (RQs) based on key themes from discussions. Different breakout groups convened to discuss what is known and unknown for each RQ and to develop sub-RQs to address gaps. Workshop attendees focused on ultra-processed foods (UPFs; Nova Group 4) because the preponderance of evidence is based on this classification system. Yet, heterogeneity and subjectivity in UPF classification was a challenge for RQ development. The 6 RQs were: 1) What objective methods or measures could further categorize UPFs, considering food processing, formulation, and the interaction of the two? 2) How can exposure assessment of UPF intake be improved? 3) Does UPF intake influence risk for obesity or CMDs, independent of diet quality? 4) What, if any, attributes of UPFs influence ingestive behavior and contribute to excess energy intake? 5) What, if any, attributes of UPFs contribute to clinically meaningful metabolic responses? 6) What, if any, external environmental factors lead people to consume high amounts of UPFs? Uncertainty and complexity around UPF intake warrant further complementary and interdisciplinary causal, mechanistic, and methodological research related to obesity and CMD risk to understand the utility of applying classification by degree of processing to foods in the United States.

Agroecology, technology, and stakeholder awareness: Implementing the UN Food Systems Summit call for action

The global food system must meet the increasing demand for food, fiber, and energy while reducing environmental impacts. The UN Food System Summit (UNFSS) has made a clear call to action for a global food systems transformation. We argue that three major discrepancies remain, potentially delaying the urgent implementation of the call to action. First, Nature-based Solutions (NbS) are not sufficiently focused on agriculture, leading to funding allocation issues. Second, a mismatch of agroecology with technology innovations may slow scaling agroecological farming. Lastly, agricultural diversification must move beyond organic landscapes and into conventional agriculture. As a solution, principles of NbS should be clear on agricultural integration. Moreover, stakeholder awareness must increase that agroecology does not necessarily conflict with agricultural technologies. Future agricultural models must apply measures such as agricultural diversification in conjunction with technology innovations to then ascertain an overall timely and successful implementation of the UNFSS call to action.

From dearth to excess: the rise of obesity in an ultra-processed food system

More people now have obesity than suffer from starvation thanks to our modern food system. Agriculture was transformed over the 20th century by a variety of technological advancements that relied heavily on fossil fuels. In the United States, government policies and economic incentives led to surplus production of cheap inputs to processed food industries that produced a wide variety of heavily marketed, convenient, rewarding, timesaving, and relatively inexpensive ultra-processed foods. The energy available in the food supply increased by much more than the population needs, albeit with large inequities in nutrition security. While most of the rise in per capita food availability during the late 20th and early 21st centuries in the United States resulted in increased food waste, a variety of mechanisms have been proposed by which changes in the increasingly ultra-processed food environment resulted in excess energy intake disproportionately in people genetically susceptible to obesity. As populations continue to grow, substantial investments in coordinated nutrition and agricultural research are needed to transform our current food system to one that relies less on fossil fuels, preserves biodiversity, ensures environmental health, and provides equitable access to affordable, safe and nutritious food that reduces the prevalence of chronic diet-related diseases like obesity. This article is part of a discussion meeting issue 'Causes of obesity: theories, conjectures and evidence (Part I)'.

Beyond ultra-processed: considering the future role of food processing in human health

Food-based dietary guidelines have been the basis of public health recommendations for over half a century, but more recently, there has been a trend to classify the health properties of food not by its nutrient composition, but by the degree to which it has been processed. This concept has been supported by many association studies, narrative reviews and the findings from one randomised controlled feeding trial, which demonstrated the sustained effect of ultra-processed diets on increasing both energy intake and body weight. This has led to widespread speculation as to specific features of ultra-processed foods that promote increased energy intakes. Rising interest in the ultra-processed topic has led to proposals to include guidance and restrictions on the consumption of processed foods in national dietary guidelines, with some countries encouraging consumers to avoid highly processed foods completely, and only choose minimally processed foods. However, there remains a lack of consensus on the role of processed foods in human health when faced with the challenges of securing the food supply for a growing global population, that is, healthy, affordable and sustainable. There has also been criticism of the subjective nature of definitions used to differentiate foods by their degree of processing, and there is currently a lack of empirical data to support a clear mechanism by which highly processed foods promote greater energy intakes. Recommendations to avoid all highly processed foods are potentially harmful if they remove affordable sources of nutrients and will be impractical for most when an estimated two-thirds of current energy purchased are from processed or ultra-processed foods. The current review highlights some considerations when interpreting the dietary association studies that link processed food intake to health and offers a critique on some of the mechanisms proposed to explain the link between ultra-processed food and poor health. Recent research suggests a combination of higher energy density and faster meal eating rates are likely to influence meal size and energy intakes from processed foods and offers new perspectives on how to manage this in the future. In going beyond the ultra-processed debate, the aim is to summarise some important considerations when interpreting existing data and identify the important gaps for future research on the role of processed food in health.

Free-choice high-fat diet consumption reduces lateral hypothalamic GABAergic activity, without disturbing neural response to sucrose drinking in mice

Nutrition can influence the brain and affect its regulation of food intake, especially that of high-palatable foods. We hypothesize that fat and sugar have interacting effects on the brain, and the lateral hypothalamus (LH) is a prime candidate to be involved in this interaction. The LH is a heterogeneous area, crucial for regulating consummatory behaviors, and integrating homeostatic and hedonic needs. GABAergic LH neurons stimulate feeding when activated, and are responsive to consummatory behavior while encoding sucrose palatability. Previously, we have shown that glutamatergic LH neurons reduce their activity in response to sugar drinking and that this response is disturbed by a free-choice high-fat diet (fcHFD). Whether GABAergic LH neurons, and their response to sugar, is affected by a fcHFD is yet unknown. Using head-fixed two-photon microscopy, we analyzed activity changes in LHVgat neuronal activity in chow or fcHFD-fed mice in response to water or sucrose drinking. A fcHFD decreased overall LHVgat neuronal activity, without disrupting the sucrose-induced increase. When focusing on the response per unique neuron, a vast majority of neurons respond inconsistently over time. Thus, a fcHFD dampens overall LH GABAergic activity, while it does not disturb the response to sucrose. The inconsistent responding over time suggests that it is not one specific subpopulation of LH GABAergic neurons that is driving these behaviors, but rather a result of the integrative properties of a complex neural network. Further research should focus on determining how this dampening of LH GABAergic activity contributes to hyperphagia and the development of obesity.

Plant-Based Dairy Alternatives Contribute to a Healthy and Sustainable Diet

Plant-based foods are increasing in popularity as more and more people are concerned about personal and planetary health. The consumption of plant-based dairy alternatives (PBDAs) has assumed a more significant dietary role in populations shifting to more sustainable eating habits. Plant-based drinks (PBDs) made from soya and other legumes have ample protein levels. PBDs that are appropriately fortified have adequate levels of important vitamins and minerals comparable to dairy milk. For the PBDs examined, the greenhouse gas emissions were diminished by 59-71% per 250 mL, and the land use and eutrophication impact was markedly less than the levels displayed by dairy milk. The water usage for the oat and soya drinks, but not rice drinks, was substantially lower compared to dairy milk. When one substitutes the 250 mL serving of dairy milk allowed within the EAT Lancet Planetary Health Diet for a fortified plant-based drink, we found that the nutritional status is not compromised but the environmental footprint is reduced. Combining a nutrient density score with an environmental index can easily lead to a misclassification of food when the full nutrition profile is not utilized or only a selection of environmental factors is used. Many PBDAs have been categorized as ultra-processed foods (UPFs). Such a classification, with the implied adverse nutritional and health associations, is inconsistent with current findings regarding the nutritional quality of such products and may discourage people from transitioning to a plant-based diet with its health and environmental advantages.

Alterations in skeletal muscle morphology and mechanics in juvenile male Sprague Dawley rats exposed to a high-fat high-sucrose diet

Although once a health concern largely considered in adults, the obesity epidemic is now prevalent in pediatric populations. While detrimental effects on skeletal muscle function have been seen in adulthood, the effects of obesity on skeletal muscle function in childhood is not clearly understood. The purpose of this study was to determine if the consumption of a high-fat high-sucrose (HFS) diet, starting in the post-weaning period, leads to changes in skeletal muscle morphology and mechanics after 14 weeks on the HFS diet. Eighteen 3-week-old male CD-Sprague Dawley rats were randomly assigned to a HFS (C-HFS, n = 10) or standard chow diet (C-CHOW, n = 8). Outcome measures included: weekly energy intake, activity levels, oxygen consumption, body mass, body composition, metabolic profile, serum protein levels, and medial gastrocnemius gene expression, morphology, and mechanics. The main findings from this study were that C-HFS rats: (1) had a greater body mass and percent body fat than control rats; (2) showed early signs of metabolic syndrome; (3) demonstrated potential impairment in muscle remodeling; (4) produced lower relative muscle force; and (5) had a shift in the force-length relationship, indicating that the medial gastrocnemius had shorter muscle fiber lengths compared to those of C-CHOW rats. Based on the results of this study, we conclude that exposure to a HFS diet led to increased body mass, body fat percentage, and early signs of metabolic syndrome, resulting in functional deficits in MG of childhood rats.

Dead rats, dopamine, performance metrics, and peacock tails: Proxy failure is an inherent risk in goal-oriented systems

When a measure becomes a target, it ceases to be a good measure. For example, when standardized test scores in education become targets, teachers may start "teaching to the test," leading to breakdown of the relationship between the measure - test performance - and the underlying goal - quality education. Similar phenomena have been named and described across a broad range of contexts, such as economics, academia, machine learning, and ecology. Yet it remains unclear whether these phenomena bear only superficial similarities, or if they derive from some fundamental unifying mechanism. Here, we propose such a unifying mechanism, which we label proxy failure. We first review illustrative examples and their labels, such as the "cobra effect," "Goodhart's law," and "Campbell's law." Second, we identify central prerequisites and constraints of proxy failure, noting that it is often only a partial failure or divergence. We argue that whenever incentivization or selection is based on an imperfect proxy measure of the underlying goal, a pressure arises that tends to make the proxy a worse approximation of the goal. Third, we develop this perspective for three concrete contexts, namely neuroscience, economics, and ecology, highlighting similarities and differences. Fourth, we outline consequences of proxy failure, suggesting it is key to understanding the structure and evolution of goal-oriented systems. Our account draws on a broad range of disciplines, but we can only scratch the surface within each. We thus hope the present account elicits a collaborative enterprise, entailing both critical discussion as well as extensions in contexts we have missed.

Predictors of state-based changes in wanting and liking

People report wanting food when they are hungry, and on eating it they typically report liking the experience. After eating, both wanting and liking decline, but wanting declines to a greater extent, which we term the 'affective discrepancy effect'. In this study we examine the predictors - state, sensory and memory-based - of these affective changes. Hungry participants undertook three tasks: (1) written recollections of what certain foods are like to eat; (2) ratings of wanting and expected flavour liking and fillingness when looking at snacks, and ratings of food and flavour liking when eating them; (3) ratings of bodily state. These tasks were then repeated after lunch. State-based changes in food liking were best predicted by changes in flavour liking. For state-based change in wanting, memory-based information about flavour liking and fillingness from tasks (1) and (2) were all significant predictors. For recollections about eating (task 1), mentions of food fillingness significantly increased pre-to post-lunch and this was the best predictor of the affective discrepancy effect. Recollections of food fillingness are state-dependent, and can arise unbidden (i.e., such recollective content was unprompted). This may reflect one way that memory may selectively influence wanting, and hence whether food intake is initiated or not.

Non-Classical Aspects of Obesity Pathogenesis and Their Relative Clinical Importance for Obesity Treatment

Obesity is a chronic disease and a major public health problem due to its association with non-communicable diseases and all-cause mortality. An increased energy intake and decreased physical activity have been long recognized as the classical parameters that contribute to the development of obesity. However, several other, non-classical factors have also been associated with obesity through various complex mechanisms. Some of them are diet related, such as diet quality, dietary habits and speed of eating. Other factors are non-dietary, such as endocrine-disrupting chemicals, sleep quality and quantity, psychotropic medications and light at night. The scope of the present narrative review is to address these non-classical factors that are implicated in the pathogenesis of obesity, to clarify their potential role in the management of obesity and, where possible, to provide some practical clinical recommendations.

Low-Grade Inflammation and Ultra-Processed Foods Consumption: A Review

Low-grade inflammation alters the homeostasis of the organism and favors the onset of many chronic diseases. The global growth in the prevalence of noncommunicable diseases in recent years has been accompanied by an increase in the consumption of ultra-processed foods (UPF). Known to be hyperpalatable, economic and ready-to-eat, increased consumption of UPF has already been recognized as a risk factor for several chronic diseases. Different research groups have tried to investigate whether UPF consumption could promote low-grade inflammation and thus favor the development of noncommunicable diseases. Current evidence highlights the adverse health effects of UPF characteristics, not only due to the nutrients provided by a diet rich in UPF, but also due to the non-nutritive components present in UPF and the effect they may have on gut health. This review aims to summarize the available evidence on the possible relationship between excessive UPF consumption and modulation of low-grade inflammation, as potential promoters of chronic disease.

Habitual daily intake of a sweet and fatty snack modulates reward processing in humans

Western diets rich in fat and sugar promote excess calorie intake and weight gain; however, the underlying mechanisms are unclear. Despite a well-documented association between obesity and altered brain dopamine function, it remains elusive whether these alterations are (1) pre-existing, increasing the individual susceptibility to weight gain, (2) secondary to obesity, or (3) directly attributable to repeated exposure to western diet. To close this gap, we performed a randomized, controlled study (NCT05574660) with normal-weight participants exposed to a high-fat/high-sugar snack or a low-fat/low-sugar snack for 8 weeks in addition to their regular diet. The high-fat/high-sugar intervention decreased the preference for low-fat food while increasing brain response to food and associative learning independent of food cues or reward. These alterations were independent of changes in body weight and metabolic parameters, indicating a direct effect of high-fat, high-sugar foods on neurobehavioral adaptations that may increase the risk for overeating and weight gain.

Hyper-palatable foods in elementary school lunches: Availability and contributing factors in a national sample of US public schools

BACKGROUND

School cafeterias are a major point of influence for child nutrition. United States federal legislation requires the presence of important nutrients in school meals. However, legislation overlooks the potential presence of hyper-palatable foods in school lunches, a hypothesized factor that may influence children's eating behavior and obesity risk. The study sought to 1) quantify the prevalence of hyper-palatable foods (HPF) served in US elementary school lunches; and 2) determine whether food hyper-palatability varied based on school geographic region (East/Central/West), urbanicity (urban/micropolitan/rural), or meal item (entrée/side/fruit or vegetable).

METHODS

Lunch menu data (N = 18 menus; N = 1160 total foods) were collected from a sample of six states that represented geographic regions of the United States (Eastern/Central/Western; Northern/Southern) and that had variability in urbanicity (urban, micropolitan, and rural) within each state. A standardized definition from Fazzino et al (2019) was used to identify HPF in lunch menus.

RESULTS

HPF comprised almost half of foods in school lunches (M = 47%; SD = 5%). Compared to fruit/vegetable items, entrées were >23 times more likely to be hyper-palatable and side dishes were >13 times more likely to be hyper-palatable (p values < .001). Geographic region and urbanicity were not significantly associated with food item hyper-palatability (p values >.05). The majority of entrée and side items contained meat/meat alternatives and/or grains and likely aligned with the US federal reimbursable meal components of meat/meat alternatives and/or grains.

CONCLUSIONS AND IMPLICATIONS

HPF comprised almost half of foods offered in elementary school lunches. Entrées and side items were most likely to be hyper-palatable. US school lunches may be a key point of regular exposure to HPF among young children, a risk factor that may elevate child obesity risk. Public policy regulating HPF in school meals may be needed to protect children's health.

Evolution of beverage portion sizes consumed in Brazil between 2008 and 2018

Objective

To describe the evolution of beverage portion sizes consumed in Brazil between 2008 and 2018.

Methods

Data from the dietary surveys of 2008-2009 and 2017-2018 Brazilian Household Budget Surveys, conducted with 34,003 and 46,164 individuals, respectively, were used to analyze the portion size of beverages. Food consumption data were used to group beverages according to nutritional characteristics, type and size of portions into eight groups: high-calorie soft drinks, fruit refreshments, alcoholic beverages, coffee/tea, fruit juices, milk and milk substitutes and ultra-processed milk-based beverages. The two-day food record and recall were considered to analyze the consumed portions. Comparisons between the surveys were done using Chi-Square tests and linear regression models.

Results

Between 2008 and 2018, the average portion consumed showed a significant increase for the group of alcoholic beverages (+29%), flavored juices (+11%), caloric soft drinks (+8%), milk and milk substitutes (+6%) and fruit juices (+5%); and reduction for the coffee/tea group (-11%). Analyzes by age group showed that among individuals between 20 and 40 years of age, the soft drinks and alcoholic beverage groups showed the greatest increase in portion size, +12 and +44%, respectively.

Conclusion

The beverage portion sizes consumed in Brazil between 2008 and 2018 increased for the group of alcoholic beverages, flavored juices, caloric soft drinks, milk and milk substitutes, and fruit juices.

Change in hyper-palatable food availability in the US food system over 30 years: 1988-2018

OBJECTIVE

To quantify the change in availability of hyper-palatable foods (HPF) in the US foods system over 30 years (1988-2018).

DESIGN

Three datasets considered representative of the US food system were used in analyses to represent years 1988, 2001 and 2018. A standardised definition from Fazzino et al. (2019) that specifies combinations of nutrients was used to identify HPF.

SETTING

Analysis of food-item level data was conducted. Differences in the prevalence of HPF were characterised by Cochran's Q and McNemar's tests. Generalised linear mixed models with a fixed effect for time and random intercept for food item estimated change in the likelihood that a food was classified as hyper-palatable over time.

PARTICIPANTS

No participant data were used.

RESULTS

The prevalence of HPF increased 20 % from 1988 to 2018 (from 49 % to 69 %; P < 0·0001). The most prominent difference was in the availability of HPF high in fat and Na, which evidenced a 17 % higher prevalence in 2018 compared with 1988 (P < 0·0001). Compared with 1988, the same food items were >2 times more likely to be hyper-palatable in 2001, and the same food items were >4 times more likely to be classified as hyper-palatable in 2018 compared with 1988 (P values < 0·0001).

CONCLUSIONS

The availability of HPF in the US food system increased substantially over 30 years. Existing food products in the food system may have been reformulated over time to enhance their palatability.

Socio-economic difference in purchases of ultra-processed foods in Australia: an analysis of a nationally representative household grocery purchasing panel

BACKGROUND

Consumption of ultra-processed foods is associated with increased risk of obesity and non-communicable diseases. Little is known about current patterns of ultra-processed foods intake in Australia. The aim of this study was to examine the amount and type of ultra-processed foods purchased by Australian households in 2019 and determine whether purchases differed by socio-economic status (SES). We also assessed whether purchases of ultra-processed foods changed between 2015 and 2019.  METHODS: We used grocery purchase data from a nationally representative consumer panel in Australia to assess packaged and unpackaged grocery purchases that were brought home between 2015 to 2019. Ultra-processed foods were identified according to the NOVA system, which classifies foods according to the nature, extent and purpose of industrial food processing. Purchases of ultra-processed foods were calculated per capita, using two outcomes: grams/day and percent of total energy. The top food categories contributing to purchases of ultra-processed foods in 2019 were identified, and differences in ultra-processed food purchases by SES (Index of Relative Social Advantage and Disadvantage) were assessed using survey-weighted linear regression. Changes in purchases of ultra-processed foods between 2015 to 2019 were examined overall and by SES using mixed linear models.

RESULTS

In 2019, the mean ± SD total grocery purchases made by Australian households was 881.1 ± 511.9 g/d per capita. Of this, 424.2 ± 319.0 g/d per capita was attributable to purchases of ultra-processed foods, which represented 56.4% of total energy purchased. The largest food categories contributing to total energy purchased included mass-produced, packaged breads (8.2% of total energy purchased), chocolate and sweets (5.7%), biscuits and crackers (5.7%) and ice-cream and edible ices (4.3%). In 2019, purchases of ultra-processed foods were significantly higher for the lowest SES households compared to all other SES quintiles (P < 0.001). There were no major changes in purchases of ultra-processed foods overall or by SES over the five-year period.

CONCLUSIONS

Between 2015 and 2019, ultra-processed foods have consistently made up the majority of groceries purchased by Australians, particularly for the lowest SES households. Policies that reduce ultra-processed food consumption may reduce diet-related health inequalities.

Withdrawal: A key consideration in evaluating whether highly processed foods are addictive

Researchers are currently debating whether theories of addiction explain compulsive overeating of highly processed (HP) foods (i.e., industrially created foods high in refined carbohydrates and/or fat), which contributes to obesity and diet-related disease. A subset of individuals consumes HP foods with behavioral phenotypes that mirror substance use disorders. Withdrawal, the emergence of aversive physical and psychological symptoms upon reduction or cessation of substance use, is a core component of addiction that was central to historical debates about other substances' addictive potential (e.g., nicotine and cocaine). However, no one has systematically considered evidence for whether HP foods cause withdrawal, which represents a key knowledge gap regarding the utility of addiction models for understanding compulsive overeating. Thus, we reviewed evidence for whether animals and humans exhibit withdrawal when reducing or eliminating HP food intake. Controlled experimental evidence indicates animals experience HP food withdrawal marked by neural reward changes and behaviors consistent with withdrawal from other addictive substances. In humans, preliminary evidence supports subjective withdrawal-like experiences. However, most current human research is limited to retrospective recall. Further experimental research is needed to evaluate this construct. We outline future research directions to investigate HP food withdrawal in humans and consider potential clinical implications.

Is there any putative mediatory role of inflammatory markers on the association between ultra-processed foods and resting metabolic rate?

The resting metabolic rate (RMR) represents the largest component of total daily energy expenditure. The sale of ultra-processed foods (UPF) is increasing globally; however, UPF can have many adverse effects, including increasing inflammatory markers and altering RMRs. This cross-sectional study included 285 healthy overweight and obese women. Anthropometric measurements were evaluated using a bioelectrical impedance analyzer InBody 770 scanner. High-sensitivity C-reactive protein (hs-CRP), plasminogen activator-1 (PAI-1), monocyte chemoattractant protein (MCP-1), and interleukin-1 beta (IL-1β) blood levels were measured after a 12-h fasting. Indirect calorimetry was used to evaluate the RMR by using the Weir equation, and RMR deviation (RMR estimated - RMR actual), RMR per body mass index (BMI), and free fat mass (FFM) were estimated. A validated food frequency questionnaire (FFQ) was used, and seven groups of UPFs were extracted based on the NOVA method. A negative association between the RMR [β = -0.159, 95% confidence interval (CI): -0.471, -0.052, P = 0.044], RMR per BMI (β = -0.014, 95% CI: -0.025, -0.006, P = 0.036), and RMR per FFM (β = -0.241, 95% CI: -0.006, -0.000, P = 0.041) using the NOVA score was observed after adjusting for confounders. This association disappeared after inclusion of each inflammatory marker. All the markers may inversely mediate the relationship between the mentioned variables and the NOVA score. hs-CRP and MCP-1 also had a negative effect on the relationship between the NOVA score and RMR deviation. Finally, UPF intake is likely related with the RMR, mediated through changes in the production of hs-CRP, PAI-1, MCP-1, and IL-1β.

Association of Food Insecurity and Food Addiction Symptoms: A Secondary Analysis of Two Samples of Low-Income Female Adults

BACKGROUND

Household food insecurity persists in the United States and has important implications for health and well-being. Food insecurity in female-identified caregivers is particularly concerning, given its association with their mental health and adverse health outcomes for their children. Food insecurity is associated with disordered eating but, to our knowledge, no prior studies have examined an association between food insecurity and food addiction.

OBJECTIVE

Our aim was to examine whether food insecurity is associated with higher food addiction symptom endorsement in low-income female adults.

DESIGN

Secondary analysis of baseline data from a quasi-experimental study of a mindfulness-based intervention on gestational weight gain among low-income pregnant individuals and an observational study of low-income families.

PARTICIPANTS/SETTING

Participants in study 1 (n = 208) were English-speaking, low-income pregnant individuals with overweight or obesity, recruited in California from 2011 to 2013. Participants in study 2 (n = 181) were English-speaking, low-income female caregivers for children aged 8 through 10 years, recruited in Michigan from 2018 to 2019. Both studies recruited participants from community health clinics, social service agencies, and online advertisements.

MAIN OUTCOME MEASURES

The primary outcome measure was food addiction symptoms, assessed by the Yale Food Addiction Scale.

STATISTICAL ANALYSIS

Multivariate Poisson regression was used to examine the association between household food insecurity and food addiction symptoms in each sample, adjusted for sociodemographic characteristics.

RESULTS

In study 1, pregnant individuals in food-insecure households reported 21% higher food addiction symptoms than pregnant individuals in food-secure households (incidence rate ratio 1.21; 95% CI 1.00 to 1.47; P = .047). In study 2, caregivers in food-insecure households had 56% higher food addiction symptoms than caregivers in food-secure households (incidence rate ratio 1.56; 95% CI 1.01 to 2.40; P = .045).

CONCLUSIONS

These findings provide preliminary support for a relationship between household food insecurity and food addiction. Future research should examine potential mechanisms and whether interventions to reduce food insecurity lower risk of food addiction.

Reduced Wheel Running via a High-Fat Diet Is Reversed by a Chow Diet with No Added Benefit from Fecal Microbial Transplants

PURPOSE

Chronic overfeeding via a high-fat/high-sugar (HFHS) diet decreases wheel running and substantially alters the gut metabolome of C57BL/6J mice. In this study, we tested the hypothesis that fecal microbial transplants can modulate the effect of diet on wheel running.

METHODS

Singly housed, 6-wk-old male C57BL/6J mice were fed either a grain-based diet (CHOW) or HFHS diet and provided a running wheel for 13 wk. Low-active, HFHS-exposed mice were then either switched to a CHOW diet and given an oral fecal microbial transplant from mice fed the CHOW diet, switched to a CHOW diet and given a sham transplant, or remained on the HFHS diet and given a fecal microbial transplant from mice fed the CHOW diet. Total wheel running, nutrient intake, body composition, fecal microbial composition, fecal metabolite composition, and liver steatosis were measured at various times throughout the study.

RESULTS

We found that an HFHS diet decreases wheel running activity, increases body fat, and decreases microbial alpha diversity compared with a CHOW diet. Improvements in wheel running, body composition, and microbial alpha diversity were accomplished within 2 wk for mice switched from an HFHS diet to a CHOW diet with no clear evidence of an added benefit from fecal transplants. A fecal transplant from mice fed a CHOW diet without altering diet did not improve wheel running or body composition. Wheel running, body composition, fecal microbial composition, fecal metabolite composition, and liver steatosis percentage were primarily determined by diet.

CONCLUSIONS

Our results suggest that diet is a primary mediator of wheel running with no clear effect from fecal microbial transplants.

The impact of caloric availability on eating behavior and ultra-processed food reward

The food environment has changed rapidly and dramatically in the last 50 years. While industrial food processing has increased the safety and stability of the food supply, a rapid expansion in the scope and scale of food processing in the 1980's has resulted in a market dominated by ultra-processed foods. Here, we use the NOVA definition of category 4 ultra-processed foods (UPFs) as they make up around 58% of total calories consumed in the US and 66% of calories in US children. UPFs are formulated from ingredients with no or infrequent culinary use, contain additives, and have a long shelf-life, spending long periods in contact with packaging materials, allowing for the absorption of compounds from those materials. The full implications of this dietary shift to UPFs on human health and disease outcomes are difficult, if not impossible, to quantify. However, UPF consumption is linked with various forms of cancer, increased cardiovascular disease, and increased all-cause mortality. Understanding food choice is, therefore, a critical problem in health research. Although many factors influence food choice, here we focus on the properties of the foods themselves. UPFs are generally treated as food, not as the highly refined, industrialized substances that they are, whose properties and components must be studied. Here, we examine one property of UPFs, that they deliver useable calories rapidly as a potential factor driving UPF overconsumption. First, we explore evidence that UPFs deliver calories more rapidly. Next, we examine the role of the gut-brain axis and its interplay with canonical reward systems, and last, we describe how speed affects both basic learning processes and drugs of abuse.

Prospective relations of maternal reward-related eating, pregnancy ultra-processed food intake and weight indicators, and feeding mode with infant appetitive traits

Background

Infant appetitive traits including eating rate, satiety responsiveness, food responsiveness, and enjoyment of food predict weight gain in infancy and early childhood. Although studies show a strong genetic influence on infant appetitive traits, the association of parent and infant appetite is understudied. Furthermore, little research examines the influence of maternal pregnancy dietary intake, weight indicators, and feeding mode on infant appetite. The present study investigated relations of maternal reward-related eating, pregnancy ultra-processed food intake and weight indicators, and feeding mode with infant appetitive traits.

Methods

Mothers in the Pregnancy Eating Attributes Study (458 mothers enrolled, 367 retained through delivery) completed self-report measures of reward-related eating, and principal component analysis yielded two components: (1) food preoccupation and responsiveness and (2) reinforcing value of food. Mothers completed 24-h dietary recalls across pregnancy, and the standardized NOVA (not an acronym) system categorized recalled foods based on processing level. Maternal anthropometrics were measured across pregnancy. At infant age 6 months, mothers reported on feeding mode and infant appetitive traits. Linear regressions were conducted predicting infant appetitive traits from household income-poverty ratio (step 1); maternal reward-related eating components (step 2); pregnancy ultra-processed food intake (% of energy intake), early pregnancy body mass index, and gestational weight gain (step 3); and exclusive breastfeeding duration (step 4).

Results

A 1-SD greater maternal food preoccupation and responsiveness was associated with 0.20-SD greater infant satiety responsiveness (p = .005). A 1-SD greater % energy intake from ultra-processed foods during pregnancy was associated with 0.16-SD lower infant satiety responsiveness (p = .031). A 1-SD longer exclusive breastfeeding duration was associated with 0.18-SD less infant food responsiveness (p = .014). Other associations of maternal reward-related eating, pregnancy ultra-processed food intake and weight indicators, and feeding mode with infant appetitive traits were non-significant.

Conclusions

Proximal early-life environmental factors including maternal pregnancy dietary intake and feeding mode may facilitate or protect against obesogenic infant appetitive traits, whereas infant appetite may not parallel maternal reward-related eating. Further investigation into the etiology of appetitive traits early in development, particularly during solid food introduction, may elucidate additional modifiable risk factors for child obesity.

Trial registration

Clinicaltrials.gov. Registration ID – NCT02217462. Date of registration – August 13, 2014.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12966-022-01334-9.

Diet-induced inflammation in the anterior paraventricular thalamus induces compulsive sucrose-seeking

Overconsumption of palatable food may initiate neuroadaptive responses in brain reward circuitry that may contribute to eating disorders. Here we report that high-fat diet (HFD) consumption impedes threat-cue-induced suppression of sucrose-seeking in mice. This compulsive sucrose-seeking was due to enhanced cue-triggered neuronal activity in the anterior paraventricular thalamus (aPVT) resulting from HFD-induced microglia activation. Thus, metabolic inflammation in the aPVT produces an adaptive response to threat cues, leading to compulsive food-seeking.

Helpful or harmful? The impact of the ketogenic diet on eating disorder outcomes in type 1 diabetes mellitus

INTRODUCTION

Eating disorders (EDs) are common complications in people with type 1 diabetes (PwT1D), given the rigid focus on food and insulin dose adjustment. Dietary recommendations for T1D match those for the general population, yet many fail to achieve target HbA1c. Evidence suggests that lower carbohydrate meals and thus reduced insulin requirements may decrease inconsistencies in insulin absorption, maintain euglycemia and weight. Dietary restriction is a recognized risk factor for ED development, and Ketogenic Diets (KD) involve restriction of common family-based foods, thus impacting social normality and microbiome diversity. We reviewed the current literature on PwT1D following a KD to understand effects on ED risks.

AREAS COVERED

Published data from MEDLINE, Embase, and PsycINFO were used. Search terms included: type 1 diabetes mellitus; or insulin dependent diabetes or T1D AND EDs or anorexia or bulimia or disordered eating AND low-carbohydrate diet or carbohydrate restricted diet or low carb diet or ketogenic diet.

EXPERT OPINION

Research into the effects of KDs on ED outcomes in PwT1D are limited, given the concerns over risks of diabetic ketoacidosis, hypoglycemia, and dyslipidemia. Longer term studies on the participants' experience and motivations of adhering or admonishing the diet are needed.

Ultra-Processed Food Consumption and Mental Health: A Systematic Review and Meta-Analysis of Observational Studies

Since previous meta-analyses, which were limited only to depression and by a small number of studies available for inclusion at the time of publication, several additional studies have been published assessing the link between ultra-processed food consumption and depression as well as other mental disorders. We aimed to build on previously conducted reviews to synthesise and meta-analyse the contemporary evidence base and clarify the associations between the consumption of ultra-processed food and mental disorders. A total of 17 observational studies were included (n = 385,541); 15 cross-sectional and 2 prospective. Greater ultra-processed food consumption was cross-sectionally associated with increased odds of depressive and anxiety symptoms, both when these outcomes were assessed together (common mental disorder symptoms odds ratio: 1.53, 95%CI 1.43 to 1.63) as well as separately (depressive symptoms odds ratio: 1.44, 95%CI 1.14 to 1.82; and, anxiety symptoms odds ratio: 1.48, 95%CI 1.37 to 1.59). Furthermore, a meta-analysis of prospective studies demonstrated that greater ultra-processed food intake was associated with increased risk of subsequent depression (hazard ratio: 1.22, 95%CI 1.16 to 1.28). While we found evidence for associations between ultra-processed food consumption and adverse mental health, further rigorously designed prospective and experimental studies are needed to better understand causal pathways.

Perspective: Soy-based Meat and Dairy Alternatives, Despite Classification as Ultra-processed Foods, Deliver High-quality Nutrition on Par with Unprocessed or Minimally Processed Animal-based Counterparts

In many non-Asian countries, soy is consumed via soy-based meat and dairy alternatives, in addition to the traditional Asian soyfoods, such as tofu and miso. Meat alternatives are typically made using concentrated sources of soy protein, such as soy protein isolate (SPI) and soy protein concentrate (SPC). Therefore, these products are classified as ultra-processed foods (UPFs; group 4) according to NOVA, an increasingly widely used food-classification system that classifies all foods into 1 of 4 groups according to the processing they undergo. Furthermore, most soymilks, even those made from whole soybeans, are also classified as UPFs because of the addition of sugars and emulsifiers. Increasingly, recommendations are being made to restrict the consumption of UPFs because their intake is associated with a variety of adverse health outcomes. Critics of UPFs argue these foods are unhealthful for a wide assortment of reasons. Explanations for the proposed adverse effects of UPFs include their high energy density, high glycemic index (GI), hyper-palatability, and low satiety potential. Claims have also been made that UPFs are not sustainably produced. However, this perspective argues that none of the criticisms of UPFs apply to soy-based meat and dairy alternatives when compared with their animal-based counterparts, beef and cow milk, which are classified as unprocessed or minimally processed foods (group 1). Classifying soy-based meat and dairy alternatives as UPFs may hinder their public acceptance, which could detrimentally affect personal and planetary health. In conclusion, the NOVA classification system is simplistic and does not adequately evaluate the nutritional attributes of meat and dairy alternatives based on soy.

Are dietary patterns becoming more processed? The effects of different dietary patterns on cognition: A review

Background: Identifying dietary patterns that promote healthy aging has become increasingly important due to changes in food processing and consumption of processed foods. Recently, the effects of these foods and unhealthy dietary patterns on cognitive function have become more widely recognized. Aim: The aim of this review is to discuss the association between various dietary patterns and cognition in older age, while also highlighting growing evidence that ultra processed food (UPF) may negatively impact healthy aging. Methods: We have performed a non-systematic literature review searches in Google Scholar electronic database with pre-defined terms relating to UPF, diet, dietary patterns, cognition and ageing. Results: The most prevalent diets in the literature include the Western, Mediterranean, Dietary Approach to Stop Hypertension (DASH), Mediterranean-DASH Intervention for Neurogenerative Delay (MIND), Japanese, Nordic, and plant-based diets. Based on the findings, higher intakes of fresh fruit and vegetables, wholegrains and oily fish are common components of dietary patterns that are positively associated with better cognitive function. In contrast, the characteristics of a Western style dietary pattern, consisting of high amounts of UPF's, are increasing in many countries even where the staple dietary pattern was identified as healthy (i.e. Japan). Conclusion: The consumption of UPF, classified by the NOVA food classification system as industrially manufactured foods containing high levels of starches, vegetable oils, sugar, emulsifiers, and foods additives, has a negative impact on the overall nutritional quality of individual diets.