How palatable food disrupts appetite regulation

Operant Training for Highly Palatable Food Alters Translating Messenger RNA in Nucleus Accumbens D2 Neurons and Reveals a Modulatory Role of Ncdn

BACKGROUND

Highly palatable food triggers behavioral responses including strong motivation. These effects involve the reward system and dopamine neurons, which modulate neurons in the nucleus accumbens (NAc). The molecular mechanisms underlying the long-lasting effects of highly palatable food on feeding behavior are poorly understood.

METHODS

We studied the effects of 2-week operant conditioning of mice with standard or isocaloric highly palatable food. We investigated the behavioral responses and dendritic spine modifications in the NAc. We compared the translating messenger RNA in NAc neurons identified by the type of dopamine receptors they express, depending on the kind of food and training. We tested the consequences of invalidation of an abundant downregulated gene, Ncdn.

RESULTS

Operant conditioning for highly palatable food increased motivation for food even in well-fed mice. In wild-type mice, free choice between regular and highly palatable food increased weight compared with access to regular food only. Highly palatable food increased spine density in the NAc. In animals trained for highly palatable food, translating messenger RNAs were modified in NAc neurons expressing dopamine D2 receptors, mostly corresponding to striatal projection neurons, but not in neurons expressing D1 receptors. Knockout of Ncdn, an abundant downregulated gene, opposed the conditioning-induced changes in satiety-sensitive feeding behavior and apparent motivation for highly palatable food, suggesting that downregulation may be a compensatory mechanism.

CONCLUSIONS

Our results emphasize the importance of messenger RNA alterations in D2 striatal projection neurons in the NAc in the behavioral consequences of highly palatable food conditioning and suggest a modulatory contribution of Ncdn downregulation.

Medium-chain triglyceride-specific appetite is regulated by the β-oxidation of medium-chain fatty acids in the liver

Most studies on fat appetite have focused on long-chain triglycerides (LCTs) due to their obesogenic properties. Medium-chain triglycerides (MCTs), conversely, exhibit antiobesogenic effects; however, the regulation of MCT intake remains elusive. Here, we demonstrate that mice can distinguish between MCTs and LCTs, and the specific appetite for MCTs is governed by hepatic β-oxidation. We generated liver-specific medium-chain acyl-CoA dehydrogenase (MCAD)-deficient (MCADL-/-) mice and analyzed their preference for MCT and LCT solutions using glyceryl trioctanoate (C8-TG), glyceryl tridecanoate (C10-TG), corn oil, and lard oil in two-bottle choice tests conducted over 8 days. In addition, we used lick microstructure analyses to evaluate the palatability and appetite for MCT and LCT solutions. Finally, we measured the expression levels of genes associated with fat ingestion (Galanin, Qrfp, and Nmu) in the hypothalamus 2 h after oral gavage of fat. Compared with control mice, MCADL-/- mice exhibited a significantly reduced preference for MCT solutions, with no alteration in the preference for LCTs. Lick analysis revealed that MCADL-/- mice displayed a significantly decreased appetite for MCT solutions only while the palatability of both MCT and LCT solutions remained unaffected. Hypothalamic Galanin expression in control mice was elevated by oral gavage of C8-TG but not by LCTs, and this response was abrogated in MCADL-/- mice. In summary, our data suggest that hepatic β-oxidation is required for MCT-specific appetite but not for LCT-specific appetite. The induction of hypothalamic galanin upon MCT ingestion, dependent on hepatic β-oxidation, could be involved in the regulation of MCT-specific appetite.NEW & NOTEWORTHY Whether and how medium-chain triglyceride (MCT) intake is regulated remains unknown. Here, we showed that mice can discriminate between MCTs and LCTs. Hepatic β-oxidation participates in MCT-specific appetite, and hypothalamic galanin may be one of the factors that regulate MCT intake. Because of the antiobesity effects of MCTs, studying MCT-specific appetite may help combat obesity by promoting the intake of MCTs instead of LCTs.

Social isolation postweaning alters reward-related dopamine dynamics in a region-specific manner in adolescent male rats

Early development is characterized by dynamic transitions in brain maturation, which may be impacted by environmental factors. Here, we sought to determine the effects of social isolation from postweaning and during adolescence on reward behavior and dopaminergic signaling in male rats. Subjects were socially isolated or group housed at postnatal day 21. Three weeks later, extracellular dopamine concentrations were examined in the medial prefrontal cortex (mPFC) and nucleus accumbens shell (NAc) during a feeding bout. Surprisingly, opposing effects were found in which increased mPFC dopamine concentrations were observed in group housed, but not isolated, rats. In stark contrast, increased dopamine levels were found in the NAc of isolated, but not group housed, rats. Moreover, the absence of an effect in the mPFC of the isolated rats could not be reversed by subsequent group housing, demonstrating the remarkable long-term effects on dopamine signaling dynamics. When provided a highly palatable food, the isolated subjects exhibited a dramatic increase in mPFC dopamine levels when the chocolate was novel, but no effects following chronic chocolate consumption. In contrast, the group housed subjects showed significantly increased dopamine levels only with chronic chocolate consumption. The dopamine changes were correlated with differences in behavioral measures. Importantly, the deficit in reward-related behavior during isolation could be reversed by microinjection of either dopamine or cocaine into the mPFC. Together, these data provide evidence that social isolation from postweaning and during adolescence alters reward-induced dopamine levels in a brain region-specific manner, which has important functional implications for reward-related behavior.

Gestational Diabetes Mellitus and Colostral Appetite-Regulating Adipokines

Gestational diabetes mellitus (GDM) is a complex metabolic disorder that has short- and long-term effects on maternal and offspring health. This study aimed to assess the impact of maternal hyperglycemia severity, classified as GDM-G1 (diet treatment) and GDM-G2 (insulin treatment) on colostral appetite-regulating molecules. Colostrum samples were collected from hyperglycemic (N = 30) and normoglycemic (N = 21) mothers, and the concentrations of milk hormones were determined by immunoenzymatic assay. A difference was found for milk ghrelin, but not for molecules such as adiponectin, leptin, resistin, or IGF-I levels, in relation to maternal hyperglycemia. The colostral ghrelin in the GDM-G1 cohort (0.21 ng/mL) was significantly lower than for GDM-G2 (0.38 ng/mL) and non-GDM groups (0.36 ng/mL). However, colostral resistin was higher, but not significantly, for GDM-G1 (13.33 ng/mL) and GDM-G2 (12.81 ng/mL) cohorts than for normoglycemic mothers (7.89 ng/mL). The lack of difference in relation to hyperglycemia for milk leptin, adiponectin, leptin-adiponectin ratio, resistin, and IGF-I levels might be the outcome of effective treatment of GDM during pregnancy. The shift between ghrelin and other appetite-regulating hormones might translate into altered ability to regulate energy balance, affecting offspring's metabolic homeostasis.

Influence of NUCB/Nesfatin-1 Polymorphism on Treatment Response to Naltrexone/Bupropion SR in Binge Eating Disorder and Obesity

Background and Objectives: The NUCB2 gene and its polymorphisms were identified as novel players in the regulation of food intake, potentially leading to obesity (OBE) and altered eating behaviors. Naltrexone/bupropion SR (NB) showed good efficacy and tolerability for treating OBE and altered eating behaviors associated with binge eating disorder (BED). This prospective study investigates the influence of NUCB2 gene polymorphism on NB treatment response in OBE and BED. Materials and Methods: Body mass index (BMI), eating (EDE-Q, BES, NEQ, GQ, Y-FAS 2.0) and general psychopathology (BDI, STAI-S) were evaluated at baseline (t0) and after 16 weeks (t1) of NB treatment in patients with OBE and BED (Group 1; N = 22) vs. patients with OBE without BED (Group 2; N = 20). Differences were evaluated according to the rs757081 NUCB2 gene polymorphism. Results: NUCB2 polymorphism was equally distributed between groups. Although weight at t0 was higher in Group 1, weight loss was similar at t1 in both groups. BMI was not influenced by NUCB2 polymorphism. In Group 1, the CG-genotype reported significant improvement in eating psychopathology while the GG-genotype reported improvement only for FA. No differences were observed in Group 2. Conclusions: Patients diagnosed with BED and treated with NB exhibited a more favorable treatment response within the CG-genotype of the NUCB2 polymorphism.

The Metabolic Syndrome, a Human Disease

This review focuses on the question of metabolic syndrome (MS) being a complex, but essentially monophyletic, galaxy of associated diseases/disorders, or just a syndrome of related but rather independent pathologies. The human nature of MS (its exceptionality in Nature and its close interdependence with human action and evolution) is presented and discussed. The text also describes the close interdependence of its components, with special emphasis on the description of their interrelations (including their syndromic development and recruitment), as well as their consequences upon energy handling and partition. The main theories on MS's origin and development are presented in relation to hepatic steatosis, type 2 diabetes, and obesity, but encompass most of the MS components described so far. The differential effects of sex and its biological consequences are considered under the light of human social needs and evolution, which are also directly related to MS epidemiology, severity, and relations with senescence. The triggering and maintenance factors of MS are discussed, with especial emphasis on inflammation, a complex process affecting different levels of organization and which is a critical element for MS development. Inflammation is also related to the operation of connective tissue (including the adipose organ) and the widely studied and acknowledged influence of diet. The role of diet composition, including the transcendence of the anaplerotic maintenance of the Krebs cycle from dietary amino acid supply (and its timing), is developed in the context of testosterone and β-estradiol control of the insulin-glycaemia hepatic core system of carbohydrate-triacylglycerol energy handling. The high probability of MS acting as a unique complex biological control system (essentially monophyletic) is presented, together with additional perspectives/considerations on the treatment of this 'very' human disease.

Higher Imported Food Patterns Are Associated with Obesity and Severe Obesity in Tuvalu: A Latent Class Analysis

Background

Tuvalu is a Pacific Island country within the small island developing states that has observed a significant and alarming increase in obesity rates over the past 40 years, affecting ∼60 %-70 % of the current population.

Objectives

This study aimed to investigate the association between food patterns and the proportion of obesity in a Pacific Island country.

Methods

The 2022 COMmunity-based Behavior and Attitude survey in Tuvalu (COMBAT) included 985 adults with complete data on sociodemographic information and the frequency of consumption of 25 common foods. A latent class analysis determined 4 food patterns. Bayesian multilevel logistic and linear regression models estimated the association between food patterns and the proportion of obesity [body mass index (BMI) ≥30 kg/m2], severe obesity (BMI ≥40 kg/m2), and weight (kg), adjusting for potential confounders and accounting for clustering by region.

Results

The latent class analysis revealed 4 food patterns with an entropy of 0.94 and an average posterior probability of class assignment for each individual of 0.97, described as follows: 1) local: locally produced foods with moderate food diversity (proportion of individuals = 28 %); 2) diverse-local: local with greater food diversity (17 %); 3) restricted-imported: more imported with restricted diversity (29 %); and 4) imported: heavily imported with high diversity (26 %). Compared to those following the diverse-local pattern, the odds of having obesity were greater for those classified with the imported pattern [odds ratio (OR): 2.52; 95 % credible interval (CrI): 1.59, 3.99], restricted-imported pattern (OR: 1.89; 95 % CrI: 1.59, 3.99), and local pattern (OR: 1.54; 95 % CrI: 0.94, 2.50). Similar trends were observed for severe obesity while body weight was positively associated with both restricted-imported and imported food patterns.

Conclusions

The high consumption of imported foods, together with the low consumption of plant-based foods and protein-rich foods, could be a relevant modifiable lifestyle factor explaining the high levels of obesity and severe obesity in Tuvalu, a Pacific Island country.

Motives and food craving: Associations with frequency of hyper-palatable food intake among college students

BACKGROUND

College food environments provide wide access to hyper-palatable foods (HPF). Palatable eating motives and craving are individual factors that may impact HPF intake. Nevertheless, no study to date has examined the relationship between these factors and frequency of HPF intake in a dormitory all-you-can-eat-style cafeteria meal, a typical college food setting.

METHODS

College students (N = 218) self-reported frequency of HPF intake at a college cafeteria meal and their frequency of HPF intake in the overall diet. Quasipoisson and logistic regression models tested whether palatable eating motives (assessed via the Palatable Eating Motives Scale) and craving (assessed via the Food Craving Inventory) were associated with the rate of HPF intake during the cafeteria meal and excess frequency of HPF intake in the overall diet.

RESULTS

Craving was associated with a 19% higher rate of HPF intake during the cafeteria meal (RR = 1.19; p = .015) and a >2-fold higher likelihood of excess frequency of HPF intake the overall diet (OR = 2.69; p < .001). Coping motive was associated with an 87% higher likelihood of excess frequency of HPF intake in the overall diet (OR = 1.87; p = .002), but not in the cafeteria meal. Reward enhancement, social and conformity motives were not significantly associated with the frequency of HPF intake in either setting.

CONCLUSIONS

Results highlight the role of craving and coping motive in the frequency of HPF intake among college students. Prevention efforts may consider targeting craving and eating to cope to potentially address frequency of HPF intake among college students.

Comparative study of dietary fat: lard and sugar as a better obesity and metabolic syndrome mice model

BACKGROUND

Diet macronutrient heterogeneity hinders animal studies' data extrapolation from metabolic disorders to human diseases.

OBJECTIVE

The present study aimed to evaluate different fat-diet compositions' effect on inducing lipid/glucose metabolism alterations in mice.

METHODS

Swiss male mice were fed for 12 weeks with five different diets: Standard Diet (ST), American Institute of Nutrition 93 for growth (AIN93G) high-butter/high-sugar (HBHS), high-lard/high-sugar (HLHS), and high-oil/high-sugar diet (soybean oil) (HOHS). Several parameters, such as serum biochemistry, histology, and liver mRNA expression, were accessed.

RESULTS

The main findings revealed that the HLHS diet dramatically altered liver metabolism inducing hepatic steatosis and increased total cholesterol, triglycerides, VLDL, increasing liver CCAAT/enhancer binding protein (CEBP-α), Acetyl-CoA carboxylase (ACC) and Catalase (CAT) mRNA expression. Moreover, the HLHS diet increased glucose intolerance and reduced insulin sensitivity.

CONCLUSIONS

High-fat/high-sugar diets are efficient to induce obesity and metabolic syndrome-associated alterations, and diets enriched with lard and sugar showed more effective results.

Intake of added sugar, fruits, vegetables, and legumes of Portuguese preschool children: Baseline data from SmartFeeding4Kids randomized controlled trial participants

Introduction

The SmartFeeding4Kids (SF4K) program is an online self-guided intervention for parents with the propose of changing parental feeding practices and children’s dietary intake, focusing on the intake of added sugars, fruit, vegetables, and legumes. This paper aims to describe children’s dietary pattern at baseline through a 24-h food recall, the SmartKidsDiet24.

Methods

Overall, 89 participants recorded at least one meal of the 3-day food recall. Mean age was 36.22 ± 6.05 years and 53.09 ± 15.42 months old for parents and children, respectively. Of these, 22 participants were considered to have 2 days of near complete 24-h food recalls. Children’s dietary intake are reported for these 22 participants based on parents reports and, thus, represent estimations only, as it remains unknown whether children consumed other non-reported foods.

Results

Fruit was the group with the highest daily intake among children (mean 1.77 ± 1.10 portions/day), followed by added sugar foods (mean 1.48 ± 0.89 portions/day), vegetables [median 1.27 (1.64) portions/day] and legumes [median 0.12 (0.39) portions/day]. Fruit intake was positively correlated with vegetable intake (p = 0.008). Regarding Dietary Reference Values accomplishment, 13.6% of children exceeded the daily safe and adequate intake of sodium, 77.3% did not meet potassium and fiber recommendations, and 31.8% did not meet vitamin C recommendations.

Discussion

All children did not meet calcium, vitamin B12 and vitamin D intake recommendations. Our findings further justify the need for dietary interventions in this field, to improve young children’s diets.

Clinical trial registration

ClinicalTrials.gov, identifier NCT04591496.

Operant training for highly palatable food alters translating mRNA in nucleus accumbens D2 neurons and reveals a modulatory role of Neurochondrin

BACKGROUND

Highly palatable food triggers behavioral alterations reminiscent of those induced by addictive drugs. These effects involve the reward system and dopamine neurons, which modulate neurons in the nucleus accumbens (NAc). The molecular mechanisms underlying the effects of highly palatable food on feeding behavior are poorly understood.

METHODS

We studied the effects of 2-week operant conditioning of mice with standard or isocaloric highly palatable food. We investigated the behavioral effects and dendritic spine modifications in the NAc. We compared the translating mRNA in NAc neurons identified by the type of dopamine receptors they express, depending on the type of food and training. We tested the consequences of invalidation of an abundant downregulated gene, Ncdn (Neurochondrin).

RESULTS

Operant conditioning for highly palatable food increases motivation for food even in well-fed mice. In control mice, free access to regular or highly palatable food results in increased weight as compared to regular food only. Highly palatable food increases spine density in the NAc. In animals trained for highly palatable food, translating mRNAs are modified in NAc dopamine D2-receptor-expressing neurons, mostly corresponding to striatal projection neurons, but not in those expressing D1-receptors. Knock-out of Ncdn, an abundant down-regulated gene, opposes the conditioning-induced changes in satiety-sensitive feeding behavior and apparent motivation for highly palatable food, suggesting down-regulation may be a compensatory mechanism.

CONCLUSIONS

Our results emphasize the importance of mRNA alterations D2 striatal projection neurons in the NAc in the behavioral consequences of highly palatable food conditioning and suggest a modulatory contribution of Ncdn downregulation.

The energetics of childhood: Current knowledge and insights into human variation, evolution, and health

How organisms capture and ultimately use metabolic energy-a limiting resource of life-has profound implications for understanding evolutionary legacies and current patterns of phenotypic variation, adaptation, and health. Energetics research among humans has a rich history in biological anthropology and beyond. The energetics of childhood, however, remains relatively underexplored. This shortcoming is notable given the accepted importance of childhood in the evolution of the unique human life history pattern as well as the known sensitivity of childhood development to local environments and lived experiences. In this review, I have three objectives: (1) To overview current knowledge regarding how children acquire and use energy, highlighting work among diverse human populations and pointing to recent advances and remaining areas of uncertainty; (2) To discuss key applications of this knowledge for understanding human variation, evolution, and health; (3) To recommend future avenues for research. A growing body of evidence supports a model of trade-offs and constraint in childhood energy expenditure. This model, combined with advancements on topics such as the energetics of immune activity, the brain, and the gut, provides insights into the evolution of extended human subadulthood and the nature of variation in childhood development, lifetime phenotype, and health.

Hyperpalatable Foods Consumption in a Representative Sample of the General Population in Brazil: Differences of Binge and Non-Binge Eating Meals

The availability of hyper-palatable foods (HPF) increased over the past three decades worldwide, a period when eating disorders (ED) and obesity have become global public health concerns. The present study aimed to assess HPF consumption during binge and non-binge meals in a representative sample of adults with and without ED from a metropolitan city in Brazil. A total of 2297 individuals were interviewed in their homes by trained lay interviewers to assess the presence of binge eating disorder (BED), bulimia nervosa (BN), and recurrent binge eating (RBE). Information on their food consumption in objective and subjective binge eating episodes (OBE and SBE, respectively), as well as in the 24 h food recall were obtained. Individuals from the general population consumed 56% of their total calories from HPF. In non-binge meals, people with BN consumed substantially fewer calories from HPF than BED (63% vs. 48%) and RBE (63% vs. 48%) groups. During OBE, participants consumed an average of 70% of the calories from HPF, with no between-group differences. During SBE, subjects with BN consumed substantially fewer calories from HPF than those with BED (76% vs. 50%). In conclusion, HPF were highly consumed by the Brazilian population. However, there was a greater impact on BED and RBE subjects and during binge eating episodes.

Food consumption patterns related to excess weight and obesity in Spanish preschoolers

PURPOSE

The aims of this study were (1) to identify the different food consumption patterns among Spanish preschoolers and (2) to examine the association between having a different food consumption pattern and the odds of having excess weight (i.e., overweight or obesity) or obesity among this population.

METHODS

This was a nationwide cross-sectional study with data from the Spanish National Health Survey-2017. All preschoolers (aged 3-5 years) with complete information on all the variables analyzed were selected. The frequency of consumption of the fourteen food groups was evaluated by a food frequency questionnaire. Excess weight/obesity were computed following the World Health Organization criteria. A hierarchical cluster analysis using Ward's method (i.e., based on squared Euclidean distances) and k-means were performed including all food group consumption. A total sample of 663 was included in the cluster analysis.

RESULTS

Three different clusters were established. Compared to the healthiest food consumption pattern (Cluster 1), higher odds of excess weight (OR = 1.51; CI: 95%, 1.02-2.25) and obesity (OR = 1.59; CI: 95%, 1.01-2.51) were found for participants with the unhealthiest food consumption pattern (Cluster 3).

CONCLUSION

Having a food consumption pattern considered unhealthy (i.e., low intake of vegetables/fruits, high consumption of confectionery products, sugar-sweetened beverages, fast-food, and snacks) was associated with presenting excess weight/obesity among Spanish preschoolers.

IMPACT

No studies have examined the specific food consumption patterns associated with excess weight or obesity among Spanish preschoolers. The unhealthiest food consumption pattern was characterized by a food consumption pattern that included a lower intake of vegetables and fruits and a higher consumption of confectionery products, sugar-sweetened beverages, fast-food, and snacks. Having a food consumption pattern considered unhealthy was associated with a higher prevalence of excess weight and obesity in comparison with other healthier food consumption patterns.

Distinct factors associated with short-term and long-term weight loss induced by low-fat or low-carbohydrate diet intervention

To understand what determines the success of short- and long-term weight loss, we conduct a secondary analysis of dietary, metabolic, and molecular data collected from 609 participants before, during, and after a 1-year weight-loss intervention with either a healthy low-carbohydrate (HLC) or a healthy low-fat (HLF) diet. Through systematic analysis of multidomain datasets, we find that dietary adherence and diet quality, not just caloric restriction, are important for short-term weight loss in both diets. Interestingly, we observe minimal dietary differences between those who succeeded in long-term weight loss and those who did not. Instead, proteomic and gut microbiota signatures significantly differ between these two groups at baseline. Moreover, the baseline respiratory quotient may suggest a specific diet for better weight-loss outcomes. Overall, the identification of these dietary, molecular, and metabolic factors, common or unique to the HLC and HLF diets, provides a roadmap for developing individualized weight-loss strategies.

An olive-derived elenolic acid stimulates hormone release from L-cells and exerts potent beneficial metabolic effects in obese diabetic mice

Insulin resistance and progressive decline in functional β-cell mass are two key factors for developing type 2 diabetes (T2D), which is largely driven by overweight and obesity, a significant obstacle for effective metabolic control in many patients with T2D. Thus, agents that simultaneously ameliorate obesity and act on multiple pathophysiological components could be more effective for treating T2D. Here, we report that elenolic acid (EA), a phytochemical, is such a dual-action agent. we show that EA dose-dependently stimulates GLP-1 secretion in mouse clonal L-cells and isolated mouse ileum crypts. In addition, EA induces L-cells to secrete peptide YY (PYY). EA induces a rapid increase in intracellular [Ca²⁺]_i and the production of inositol trisphosphate in L-cells, indicating that EA activates phospholipase C (PLC)-mediated signaling. Consistently, inhibition of (PLC) or Gα_q ablates EA-stimulated increase of [Ca²⁺]_i and GLP-1 secretion. In vivo, a single dose of EA acutely stimulates GLP-1 and PYY secretion in mice, accompanied with an improved glucose tolerance and insulin levels. Oral administration of EA at a dose of 50 mg/kg/day for 2 weeks normalized the fasting blood glucose and restored glucose tolerance in high-fat diet-induced obese (DIO) mice to levels that were comparable to chow-fed mice. In addition, EA suppresses appetite, reduces food intake, promotes weight loss, and reverses perturbated metabolic variables in obese mice. These results suggest that EA could be a dual-action agent as an alternative or adjuvant treatment for both T2D and obesity.

The Burden of Carbohydrates in Health and Disease

Foods high in carbohydrates are an important part of a healthy diet, since they provide the body with glucose to support bodily functions and physical activity. However, the abusive consumption of refined, simple, and low-quality carbohydrates has a direct implication on the physical and mental pathophysiology. Then, carbohydrate consumption is postulated as a crucial factor in the development of the main Western diseases of the 21st century. We conducted this narrative critical review using MedLine (Pubmed), Cochrane (Wiley), Embase, and CinAhl databases with the MeSH-compliant keywords: carbohydrates and evolution, development, phylogenetic, GUT, microbiota, stress, metabolic health, consumption behaviors, metabolic disease, cardiovascular disease, mental disease, anxiety, depression, cancer, chronic kidney failure, allergies, and asthma in order to analyze the impact of carbohydrates on health. Evidence suggests that carbohydrates, especially fiber, are beneficial for the well-being and growth of gut microorganisms and consequently for the host in this symbiotic relationship, producing microbial alterations a negative effect on mental health and different organic systems. In addition, evidence suggests a negative impact of simple carbohydrates and refined carbohydrates on mood categories, including alertness and tiredness, reinforcing a vicious circle. Regarding physical health, sugar intake can affect the development and prognosis of metabolic disease, as an uncontrolled intake of refined carbohydrates puts individuals at risk of developing metabolic syndrome and subsequently developing metabolic disease.

Utility of 'substance use disorder' as a heuristic for understanding overeating and obesity

Rates of obesity and obesity-associated diseases have increased dramatically in countries with developed economies. Substance use disorders (SUDs) are characterized by the persistent use of the substance despite negative consequences. It has been hypothesized that overconsumption of palatable energy dense food can elicit SUD-like maladaptive behaviors that contribute to persistent caloric intake beyond homeostatic need even in the face of negative consequences. Palatable food and drugs of abuse act on many of the same motivation-related circuits in the brain, and can induce, at least superficially, similar molecular, cellular, and physiological adaptations on these circuits. As such, applying knowledge about the neurobiological mechanisms of SUDs may serve as useful heuristic to better understand the persistent overconsumption of palatable food that contributes to obesity. However, many important differences exist between the actions of drugs of abuse and palatable food in the brain. This warrants caution when attributing weight gain and obesity to the manifestation of a putative SUD-related behavioral disorder. Here, we describe similarities and differences between compulsive drug use in SUDs and overconsumption in obesity and consider the merit of the concept of "food addiction".

Hyper-palatable food consumption during binge-eating episodes: A comparison of intake during binge eating and restricting

OBJECTIVE

The study aim was to elucidate the degree to which hyper-palatable foods (HPF) are consumed during binge episodes compared to restricting episodes, and to test the association between HPF intake during each episode and respective episode frequency.

METHOD

This study was a secondary analysis of data from a larger study on eating disorders. The present sample included adults (N = 147, 83% women) diagnosed with sub-threshold (41%) or full-threshold (59%) bulimia nervosa (BN). Foods consumed during binge and restricting episodes were assessed using the Eating Pathology Symptoms Inventory-Clinician Rated Version. A standardized definition of HPF developed previously was applied to foods consumed during binge and restricting episodes. A Wilcoxon matched-pairs signed-rank test was used to test the difference between total caloric intake from HPF (KcalHPF) and percentage of caloric intake from HPF (PercHPF) during binge episodes relative to restricting episodes. Four linear regression models tested HPF intake (KcalHPF and PercHPF) during both episode types (binge and restricting) as predictors of respective episode frequency.

RESULTS

There was a significant difference between median KcalHPF (1846.6 vs. 279.6; Z = -13.38, p < .001) and PercHPF during binge compared to restricting episodes (95% vs. 61%; Z = -7.35, p < .001). Regression analyses demonstrated that KcalHPF during binge episodes was significantly associated with binge episode frequency (B = 0.002; p < .001), but not PercHPF (p = .287).

DISCUSSION

Results suggest that HPF may be primarily consumed during binge episodes among individuals with BN, and may be associated with greater binge-eating frequency.

PUBLIC SIGNIFICANCE

Findings from the current study support an underlying assumption of theoretical models of binge eating, suggesting that highly rewarding, hyper-palatable foods (HPF), may constitute the vast majority of energy intake during binge-eating episodes. Additionally, a substantial amount of energy intake from HPF may occur during restricting episodes among people with bulimia nervosa. Greater HPF intake during binge eating may also be associated with binge-eating severity.

Sugar-sweetened beverages, effects on appetite and public health strategies to reduce the consumption among children: a review

Sugar-sweetened beverages (SSBs) consumption have been of public health concern and a target of interventions due to their high consumption and burden in health-related consequences, particularly in children and adolescents. SSBs provide high energy intake with low nutritional value and are a major contributor for added and free sugars intake of Portuguese in all age-groups, especially adolescents. Despite its recognized effect on weight gain, it might also disrupt appetite regulation. Research on the effect of SSBs on appetitive traits is still scarce and unclear, and the current knowledge of these potential effects will be discussed in this review. This review also aims to describe public health strategies implemented to decrease SSBs consumption among children, particularly in Portugal, such as: (i) implemented taxation measures and its impact in sales and in preventable cases of disease and death, (ii) marketing regulations applied to children and adolescents, and ultimately (iii) the intention of application of a single Front-of-Package labeling system in all countries, aiming to increase consumers’ food literacy.

Metabolic benefits of novel histamine H3 receptor ligands in the model of excessive eating: The importance of intrinsic activity and pharmacokinetic properties

AIMS

One of the therapeutic approaches in the treatment of obesity is the use of histamine H3 receptor ligands. Histamine plays a significant role in eating behavior because it causes a loss of appetite and is considered to be a satiety signal released during food intake.

MATERIAL AND METHODS

Histamine ligands were selected based on the preliminary studies which included determination of intrinsic activity and selected pharmacokinetic parameters. Female Wistar rats were fed palatable feed for 28 days and simultaneously the tested compounds were administered intraperitoneally at a dose of 10 mg/kg b.w./day. Rats' weight was evaluated daily and calories intake was evaluated once per week. At the end of experiment insulin and glucose tolerance tests was performed. Plasma levels of cholesterol, triglycerides, leptin, insulin, glucose, C-peptide and CRP were also determined. In order to rule out false-positive results the influence of tested compounds on spontaneous activity of rats was monitored.

RESULTS

Animals fed palatable feed and treated with KSK-61 or KSK-63 compounds showed the slowest weight gain which was comparable to the one observed in control animals. Both compounds with the highest pharmacological activity have also similar pharmacokinetic properties with quite long half-life and high volume of distribution indicating that they can freely cross most biological barriers. Some compounds, especially KSK-63, compensated for metabolic disorders.

CONCLUSION

The presented study proves that search among the active histamine H3 receptor ligands for the new therapeutic agents to treat obesity is justified. Compounds KSK-61 and KSK-63 can be considered as the leading structures.

Packaged Foods Labeled as Organic Have a More Healthful Profile Than Their Conventional Counterparts, According to Analysis of Products Sold in the U.S. in 2019-2020

The organic food market’s recent rapid global growth reflects the public’s interest in buying certified organic foods, including packaged products. Our analysis shows that packaged foods containing fewer ingredients associated with negative public health outcomes are more likely to be labeled organic. Previous studies comparing organic and conventional foods focused primarily on nutrient composition. We expanded this research by additionally examining ingredient characteristics, including processing and functional use. Our dataset included nutrition and ingredient data for 8240 organic and 72,205 conventional food products sold in the U.S. from 2019 to 2020. Compared to conventional foods, organic foods in this dataset had lower total sugar, added sugar, saturated fat and sodium content. Using a mixed effects logistic regression, we found that likelihood of classification as organic increased as sodium content, added sugar content and the number of ultra-processed ingredients and cosmetic additives on the product label decreased. Products containing no trans-fat ingredients were more likely to be labeled organic. A product was more likely to be classified “organic” the more potassium it contained. These features of organic foods sold in the U.S. are significant because lower dietary ingestion of ultra-processed foods, added sugar, sodium and trans-fats is associated with improved public health outcomes.

Congenital Anomalies Programmed by Maternal Diabetes and Obesity on Offspring of Rats

Embryo-fetal exposure to maternal disorders during intrauterine life programs long-term consequences for the health and illness of offspring. In this study, we evaluated whether mild diabetic rats that were given high-fat/high-sugar (HF/HS) diet presented maternal and fetal changes at term pregnancy. Female rats received citrate buffer (non-diabetic-ND) or streptozotocin (diabetic-D) after birth. According to the oral glucose tolerance test (OGTT), the experimental groups (n = 11 animals/group) were composed of non-diabetic and diabetic receiving standard diet (S) or HF/HS diet. High-fat/high-sugar diet (30% kcal of lard) in chow and water containing 5% sucrose and given 1 month before mating and during pregnancy. During and at the end of pregnancy, obesity and diabetes features were determined. After laparotomy, blood samples, periovarian fat, and uterine content were collected. The diabetic rats presented a higher glycemia and percentage of embryonic losses when compared with the NDS group. Rats DHF/HS presented increased obesogenic index, caloric intake, and periovarian fat weight and reduced gravid uterus weight in relation to the other groups. Besides, this association might lead to the inflammatory process, confirmed by leukocytosis. Obese rats (NDHF/HS and DHF/HS) showed higher triglyceride levels and their offspring with lower fetal weight and ossification sites, indicating intrauterine growth restriction. This finding may contribute to vascular alterations related to long-term hypertensive disorders in adult offspring. The fetuses from diabetic dams showed higher percentages of skeletal abnormalities, and DHF/HS dams still had a higher rate of anomalous fetuses. Thus, maternal diabetes and/or obesity induces maternal metabolic disorders that contribute to affect fetal development and growth.

CRISPR knockdown of Kcnq3 attenuates the M-current and increases excitability of NPY/AgRP neurons to alter energy balance

OBJECTIVE

Arcuate nucleus neuropeptide Y/agouti-related peptide (NPY/AgRP) neurons drive ingestive behavior. The M-current, a subthreshold non-inactivating potassium current, plays a critical role in regulating NPY/AgRP neuronal excitability. Fasting decreases while 17β-estradiol increases the M-current by regulating the mRNA expression of Kcnq2, 3, and 5 (Kv7.2, 3, and 5) channel subunits. Incorporating KCNQ3 into heteromeric channels has been considered essential to generate a robust M-current. Therefore, we investigated the behavioral and physiological effects of selective Kcnq3 deletion from NPY/AgRP neurons.

METHODS

We used a single adeno-associated viral vector containing a recombinase-dependent Staphylococcus aureus Cas9 with a single-guide RNA to selectively delete Kcnq3 in NPY/AgRP neurons. Single-cell quantitative measurements of mRNA expression and whole-cell patch clamp experiments were conducted to validate the selective knockdown. Body weight, food intake, and locomotor activity were measured in male mice to assess disruptions in energy balance.

RESULTS

The virus reduced the expression of Kcnq3 mRNA without affecting Kcnq2 or Kcnq5. The M-current was attenuated, causing NPY/AgRP neurons to be more depolarized, exhibit a higher input resistance, and require less depolarizing current to fire action potentials, indicative of increased excitability. Although the resulting decrease in the M-current did not overtly alter ingestive behavior, it significantly reduced the locomotor activity as measured by open-field testing. Control mice on a high-fat diet exhibited an enhanced M-current and increased Kcnq2 and Kcnq3 expression, but the M-current remained significantly attenuated in KCNQ3 knockdown animals.

CONCLUSIONS

The M-current plays a critical role in modulating the intrinsic excitability of NPY/AgRP neurons that is essential for maintaining energy homeostasis.

Perceived Intensity and Palatability of Fatty Culinary Preparations is Associated with Individual Fatty Acid Detection Threshold and the Fatty Acid Profile of Oils Used as Ingredients

The term oleogustus was recently proposed to describe a sixth basic taste that could guide preference for fatty foods and dishes to an extent. However, experimental data on food preference based on fatty acid (FA) content is scarce. Our aim was to examine the role of FA profile of oils and preparations as well as FA sensory thresholds on the palatability of salty and sweet culinary preparations representative of traditional Spanish Mediterranean cooking. In this study, we used three oils with similar texture and odor profile but different in their FA composition (saturated, monounsaturated, and polyunsaturated) and compared subjects in regard to their FA detection threshold and perceived pleasantness and intensity. Our results indicate that whereas saturated FAs cannot be detected at physiological concentrations, individuals can be categorized as tasters and nontasters, according to their sensory threshold to linoleic acid, which is negatively associated with perceived intensity (r = -0.393, P < 0.001) but positively with palatability (r = 0.246, P = 0.018). These differences may be due to a possible response to a fat taste. This sixth taste, or oleogustus. would allow establishing differences in taste intensity/palatability considering the FA profile of the culinary preparations. Given that tasters can detect linoleic and oleic acid at lower concentrations than nontasters, a greater amount of unsaturated FAs in culinary preparations could provoke an unpleasant experience. This finding could be relevant in the context of the culinary sector and to further our understanding of food preference and eating behavior.

Obesity, Mediterranean Diet, and Public Health: A Vision of Obesity in the Mediterranean Context from a Sociocultural Perspective

Obesity is a disease that straddles medico-nutritional, psychological, and socio-cultural boundaries. There is a clear relationship between lifestyle and obesity, and today the Mediterranean diet in the Mediterranean area may represent an interesting corrective asset. However, we should not be under any misapprehension about the model’s capacity for action in non-nutritional terms. Our societies are experiencing a process of rapid change, and the Mediterranean area is no exception. The aim of this article is to present a view of obesity in the Mediterranean context from an open, mainly socio-cultural perspective, but from different points of view (medical, nutritional), seeking points of convergence and elements that contribute to the understanding of and approach to the disease in the context of the Mediterranean diet. As a public health and a multidimensional social problem, obesity must be dealt with in a holistic, open, and cross-disciplinary manner to ensure that it can be understood coherently. The only way to keep the usefulness of the Mediterranean diet within desirable limits will be our societies’ vitality and interest in rapidly adapting the Mediterranean diet to social change, thus providing valid answers to today’s needs.

Oral Signals of Short and Long Chain Fatty Acids: Parallel Taste Pathways to Identify Microbes and Triglycerides

Both short chain fatty acids (SCFAs) and long chain fatty acids (LCFAs) rely on free fatty acid receptors to signal their presence to the body, but their individual detection and putative reward systems are different. These separate, yet parallel, taste signaling pathways allow us to distinguish microbe-produced from triglyceride-based fatty acids. Free SCFAs indicate that the food has been fermented and may still contain living, probiotic microbes that can colonize the gut. Free LCFAs indicate the presence of calorie-rich triglycerides in foods. By contrast, LCFAs stimulate endocannabinoids, which reinforce overconsumption of triglycerides. Here we examine the separate oral detection and putative reward systems for both LCFA and SCFAs, and introduce a novel dietary LC:SC ratio as a guideline to improve metabolism and health.

DAT1 and Its Psychological Correlates in Children with Avoidant/Restrictive Food Intake Disorder: A Cross-Sectional Pilot Study

International research has underlined the role played by children’s and maternal psychopathological symptoms on the onset of avoidant/restrictive food intake disorder (ARFID) in early childhood. No study has considered the possible interplay between children’s dopamine transporter (DAT1) genotype and methylation, dysregulation problems and maternal psychopathological risk. This study aimed to investigate the complex relationship between these variables, considering the possible mediation role played by children’s DAT1 methylation on the relationship between mothers’ psychopathological risk and children’s dysregulation problems, moderated by children’s DAT1 genotype. Our sample consisted of 94 early children and their mothers, divided into four subgroups, based on children’s ARFID subtypes (irritable/impulsive (I/I), sensory food aversions (SFA), post-traumatic feeding disorders subtypes (PTFD), and a non-clinical group (NC)). We addressed children’s dysregulation problems and maternal psychopathological risk, and collected children’s DNA through buccal swabs. Results showed that children’s 9/x genotype was associated with PTFD and NC groups, whereas the 10/10 genotype was associated with the SFA group, with large effect size. There were significant large differences in the study groups on children’s DAT1 total methylation, children’s dysregulation problems, and maternal psychopathological risk. Children’s DAT1 methylation did not mediate the relationship between mother’s psychopathological risk and children’s dysregulation problems, but there was a significant large direct effect. Children’s 9/x genotype moderated the relationship between maternal psychopathological risk and children’s DAT1 methylation but, respectively, with a large and small effect. Our pilot study suggested that the relationship between children’s DAT1 genotype and methylation, dysregulation problems, and maternal psychopathological risk has a crucial contribution to ARFID.

Perceived Nutrition and Health Concerns: Do They Protect against Unhealthy Dietary Patterns in Polish Adults?

The aim of the study was to explore the associations between perceived health and nutrition concerns, sociodemographic characteristics and unhealthy dietary patterns in a representative group of Polish adults. The data were collected in 2017 through a cross-sectional quantitative survey under the National Health Program 2016-2020. Logistic regression models were used to analyze the data. It was found that higher health concerns decreased the chances of adhering to upper tertiles of "Fast food & alcohol" and "Refined food & sweetened beverages" dietary patterns (DPs), thus displaying less frequent consumption of such foods. No relationship was found between health concerns and adhering to the "Fat food" and "Butter" DPs. Nutrition concerns increased the likelihood of frequent consumption of foods from "Fast food & alcohol" DP. Women were less likely to adhere to unhealthy eating patterns than men, while older people were less likely to often consume fast food, alcohol, or refined food and sweetened beverages. Findings of this study showed that concerns about health or nutrition were differently associated with dietary patterns and consumption of unhealthy foods. These relationships should be considered when developing interventions to address health-related lifestyle changes. However, further research is needed to identify cause-effect relationships between these variables.

An assessment of rapamycin for weakening binge-eating memories via reconsolidation: a pre-registered, double-blind randomised placebo-controlled experimental study

BACKGROUND

Maladaptive learning linking environmental food cues to high-palatability food reward plays a central role in overconsumption in obesity and binge eating disorders. The process of memory reconsolidation offers a mechanism to weaken such learning, potentially ameliorating over-eating behaviour. Here we investigated whether putatively interfering with synaptic plasticity using the mammalian target of rapamycin (mTOR) inhibitor, rapamycin, could weaken retrieved chocolate reward memories through blockade of reconsolidation.

METHODS

Seventy five healthy volunteers with a tendency to binge eat chocolate were randomised to retrieve chocolate reward memory under 10 mg rapamycin (RET + RAP, active condition), or placebo (RET + PBO), or they received 10 mg rapamycin without subsequent retrieval (NO RET + RAP). Indices of chocolate reward memory strength were assessed one week pre and post manipulation and at one month follow-up.

RESULTS

Contrary to hypotheses, the RET + RAP group did not show any greater reduction than control groups on indices of motivational salience of chocolate cues, motivation to consume chocolate or liking of chocolate. Mild evidence of improvement in the RET + RAP group was found, but this was limited to reduced chocolate binge episodes and improved healthy food choices.

CONCLUSIONS

We did not find convincing evidence of comprehensive naturalistic chocolate reward memory reconsolidation blockade by rapamycin. The effects on chocolate bingeing and food choices may warrant further investigation. These limited positive findings may be attributable to insufficient interference with mTOR signalling with 10 mg rapamycin, or failure to destabilise chocolate memories during retrieval.

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.

Effect of a responsive parenting intervention on child emotional overeating is mediated by reduced maternal use of food to soothe: The INSIGHT RCT

BACKGROUND

Child emotional overeating is a risk factor for obesity that is learned in the home environment. Parents' use of food to soothe child distress may contribute to the development of children's emotional overeating.

OBJECTIVES

To examine the effect of a responsive parenting (RP) intervention on mother-reported child emotional overeating, and explore whether effects are mediated by mother-reported use of food to soothe child distress.

METHODS

The sample included primiparous mother-infant dyads randomized to a RP intervention (n = 105) or home safety control group (n = 102). Nurses delivered RP guidance in four behavioral domains: sleeping, fussy, alert/calm, and drowsy. Mothers reported their use of food to soothe at age 18 months and child emotional overeating at age 30 months. Mediation was analyzed using the SAS PROCESS macro.

RESULTS

RP intervention mothers reported less frequent use of food to soothe and perceived their child's emotional overeating as lower compared to the control group. Food to soothe mediated the RP intervention effect on child emotional overeating (mediation model: R² = 0.13, P < .0001).

CONCLUSIONS

Children's emotional overeating may be modified through an early life RP intervention. Teaching parents alternative techniques to soothe child distress rather than feeding may curb emotional overeating development to reduce future obesity risk.

Internally regulated eating style: a comprehensive theoretical framework

Internally regulated eating style, the eating style that is driven by internal bodily sensations of hunger and satiation, is a concept that has received increasing attention in the literature and health practice over the last decades. The various attempts that have been made so far to conceptualise internally regulated eating have taken place independently of one another, and each sheds light on only parts of the total picture of what defines internally regulated eating. This has resulted in a literature that is rather fragmented. More importantly, it is not yet clear which are the characteristics that comprise this eating style. In this paper, we identify and describe the full spectrum of these characteristics, namely, sensitivity to internal hunger and satiation signals, self-efficacy in using internal hunger and satiation signals, self-trusting attitude for the regulation of eating, relaxed relationship with food and tendency to savour the food while eating. With this research, we introduce a common language to the field and we present a new theoretical framework that does justice not just to the full breadth of characteristics that are necessary for the internally regulated eating style but also to the associations between them and the potential mechanisms by which they contribute to this eating style.

Nesfatin-1 decreases the motivational and rewarding value of food

Homeostatic and hedonic pathways distinctly interact to control food intake. Dysregulations of circuitries controlling hedonic feeding may disrupt homeostatic mechanisms and lead to eating disorders. The anorexigenic peptides nucleobindin-2 (NUCB2)/nesfatin-1 may be involved in the interaction of these pathways. The endogenous levels of this peptide are regulated by the feeding state, with reduced levels following fasting and normalized by refeeding. The fasting state is associated with biochemical and behavioral adaptations ultimately leading to enhanced sensitization of reward circuitries towards food reward. Although NUCB2/nesfatin-1 is expressed in reward-related brain areas, its role in regulating motivation and preference for nutrients has not yet been investigated. We here report that both dopamine and GABA neurons express NUCB2/nesfatin-1 in the VTA. Ex vivo electrophysiological recordings show that nesfatin-1 hyperpolarizes dopamine, but not GABA, neurons of the VTA by inducing an outward potassium current. In vivo, central administration of nesfatin-1 reduces motivation for food reward in a high-effort condition, sucrose intake and preference. We next adopted a 2-bottle choice procedure, whereby the reward value of sucrose was compared with that of a reference stimulus (sucralose + optogenetic stimulation of VTA dopamine neurons) and found that nesfatin-1 fully abolishes the fasting-induced increase in the reward value of sucrose. These findings indicate that nesfatin-1 reduces energy intake by negatively modulating dopaminergic neuron activity and, in turn, hedonic aspects of food intake. Since nesfatin-1´s actions are preserved in conditions of leptin resistance, the present findings render the NUCB2/nesfatin-1 system an appealing target for the development of novel therapeutical treatments towards obesity.

Association between health literacy and dietary intake of sugar, fat and salt: a systematic review

Objectives:

To collect and summarise all current data from observational studies, generating evidence of the association between health literacy (HL) and the dietary intake of sugar, salt and fat, to analyse intervention studies on the promotion of an appropriate dietary intake of the above-mentioned nutrients and to ascertain whether HL moderates the efficacy of such intervention.

Design:

A systematic literature search of analytical observational studies on the association between HL and dietary intake of sugar, salt and fat was performed in Medline and Scopus databases. Intervention studies on the promotion of healthy nutrition that concerned the intake of sugar, salt and fat were also assessed.

Results:

Of the eight observational studies included in this review, five investigated dietary intake of sugar, one focused on salt, one assessed sugar and salt and one analysed the fat intake. The results of the five studies assessing sugar were mixed: three found an association between low levels of HL and a high sugar intake, one found this association only for boys and two found no evidence of any association. The two studies assessing salt and the one assessing fat found no evidence of any association with HL. One intervention study on the sugar intake concluded that HL was not a significant moderator of the intervention’s effectiveness.

Conclusion:

No evidence of any association between HL and salt and fat intake emerged, while for sugar, the results are mixed. More work is needed to better understand the moderating effects of HL on the outcomes of health promotion interventions.

Maternal exercise during gestation and lactation decreases high-fat diet preference by altering central reward system gene expression in adult female offspring from high-fat fed dams

Exposure to maternal high-fat (HF) diet during gestation and lactation alters adult offspring's feeding behavior and diet preference. However, the impact of maternal exercise on offspring's diet preference and reward system development is less studied. In this study, we investigate the effect of perinatal maternal exercise on the development of diet preference, dopamine- and opioid-related gene expression in the central reward system in female offspring from HF-fed Sprague-Dawley rat dams. We found maternal HF diet did not alter adult offspring HF preference, but influenced offspring's dopamine and opioid system both at weaning and in adulthood, and these offspring retained higher body weight in adulthood. However, offspring from dams exposed to both HF diet and exercise during gestation and lactation had normalized body weight, decreased fat mass and lower HF-diet preference but increased energy intake in adulthood. The dopamine- and opioid-related gene expression in central reward system and POMC expression in hypothalamus was elevated in these adult offspring. We conclude that maternal exercise during gestation and lactation can potentially overcome the negative effects of perinatal exposure to HF diet in female offspring by altering their diet preference, central reward system signaling and hypothalamus neuropeptide expression.

Role of melanin-concentrating hormone in drug use disorders

Melanin-concentrating hormone (MCH) is a neuropeptide primarily transcribed in the lateral hypothalamus (LH), with vast projections to many areas throughout the central nervous system that play an important role in motivated behaviors and drug use. Anatomical, pharmacological and genetic studies implicate MCH in mediating the intake and reinforcement of commonly abused substances, acting by influencing several systems including the mesolimbic dopaminergic system, glutamatergic as well as GABAergic signaling and being modulated by inflammatory neuroimmune pathways. Further support for the role of MCH in controlling behavior related to drug use will be discussed as it relates to cerebral ventricular volume transmission and intracellular molecules including cocaine- and amphetamine-regulated transcript peptide, dopamine- and cAMP-regulated phosphoprotein 32 kDa. The primary goal of this review is to introduce and summarize current literature surrounding the role of MCH in mediating the intake and reinforcement of commonly abused drugs, such as alcohol, cocaine, amphetamine, nicotine and opiates.

Modulation of Pain Sensitivity by Chronic Consumption of Highly Palatable Food Followed by Abstinence: Emerging Role of Fatty Acid Amide Hydrolase

There is a strong relationship between palatable diet and pain sensitivity, and the cannabinoid and opioid systems might play an important role in this correlation. The palatable diet used in many animal models of obesity is the cafeteria (CAF) diet, based on human food with high sugar, salt, and fat content. In this study, we investigated whether long-term exposure to a CAF diet could modify pain sensitivity and explored the role of the cannabinergic system in this modification. Male Sprague–Dawley rats were divided into two groups: one fed with standard chow only (CO) and the other with extended access (EA) to a CAF diet. Hot plate and tail flick tests were used to evaluate pain sensitivity. At the end of a 40-day CAF exposure, EA rats showed a significant increase in the pain threshold compared to CO rats, finding probably due to up-regulation of CB1 and mu-opioid receptors. Instead, during abstinence from palatable foods, EA animals showed a significant increase in pain sensibility, which was ameliorated by repeated treatment with a fatty acid amide hydrolase inhibitor, PF-3845 (10 mg/kg, intraperitoneally), every other day for 28 days. Ex vivo analysis of the brains of these rats clearly showed that this effect was mediated by mu-opioid receptors, which were up-regulated following repeated treatment of PF-3845. Our data add to the knowledge about changes in pain perception in obese subjects, revealing a key role of CB1 and mu-opioid receptors and their possible pharmacological crosstalk and reinforcing the need to consider this modulation in planning effective pain management for obese patients.

Food Reward and Food Choice. An Inquiry Through The Liking and Wanting Model

What if consumers are getting obese because eating less calories is more difficult for persons that have a higher pleasure and desire towards food (Ikeda et al., 2005) and food companies do not help given only a two extreme option choice to satisfy their needs (i.e., low calories vs. high calories or healthy vs. unhealthy)? Reward systems are being described with a new conceptual approach where liking—the pleasure derived from eating a given food—and wanting—motivational value, desire, or craving—can be seen as the significant forces guiding eating behavior. Our work shows that pleasure (liking), desire (wanting), and the interaction between them influence and are good predictors of food choice and food intake. Reward responses to food are closely linked to food choice, inducing to caloric overconsumption. Based on the responses given to a self-administered questionnaire measuring liking and wanting attitudes, we found three different segments named ‘Reward lovers,’ ‘Half epicurious,’ and ‘Non indulgents’. Their behavior when choosing food is quite different. Results show differential effects on caloric consumption depending on segments. The introduction of more food choices that try to balance their content is a win-win strategy for consumers, companies, and society.

Obesity and adiposity: the culprit of dietary protein efficacy

Obesity and increased body adiposity have been alarmingly increasing over the past decades and have been linked to a rise in food intake. Many dietary restrictive approaches aiming at reducing weight have resulted in contradictory results. Additionally, some policies to reduce sugar or fat intake were not able to decrease the surge of obesity. This suggests that food intake is controlled by a physiological mechanism and that any behavioural change only leads to a short-term success. Several hypotheses have been postulated, and many of them have been rejected due to some limitations and exceptions. The present review aims at presenting a new theory behind the regulation of energy intake, therefore providing an eye-opening field for energy balance and a potential strategy for obesity management.

Effects of Maternal Dietary Patterns during Pregnancy on Early Childhood Growth Trajectories and Obesity Risk: The CANDLE Study

We investigated the associations between maternal dietary patterns during pregnancy and early childhood growth trajectories and overweight/obesity risk in offspring. Maternal diet was assessed using a food frequency questionnaire during the second trimester, and dietary patterns were derived by reduced rank regression. The associations between maternal dietary pattern scores and body mass index (BMI) trajectories from birth to age four (rising-high, moderate, and low BMI trajectories) as well as overweight/obesity risk at age four were analyzed (n = 1257). Two maternal dietary patterns were identified. The fast food pattern included a higher intake of fried chicken and fish, fruit juices, mayonnaise, and sugar-sweetened beverages, while the processed food pattern included a higher intake of dairy, salad dressing, processed meat, and cold breakfast cereal. Women with greater adherence to the fast food pattern were more likely to have children in the rising-high BMI trajectory group [OR (95% CI) = 1.32 (1.07-1.62); p = 0.008] or having overweight/obesity at age four [OR (95% CI) = 1.31 (1.11-1.54); p = 0.001]. The processed food pattern was not associated with these outcomes. The maternal dietary pattern during pregnancy represented by fried foods and sugar-sweetened beverages may contribute to rapid early childhood growth and increased risk for obesity in offspring.

Factors affecting emotional eating and eating palatable food in adults

BACKGROUND/OBJECTIVES

The aim of this study was to determine the relationship among emotional eating behavior, tendency to eat palatable foods, and several risk factors.

SUBJECTS/METHODS

This study was carried out on 2,434 persons (1,736 women and 698 men) aged between 19 and 64 years. A questionnaire form was used as a data collection tool, which consisted of items for the socio-demographic characteristics, anthropometric measurements, Emotional Appetite Questionnaire (EMAQ), and the Palatable Eating Motives Scale (PEMS).

RESULTS

A positive significant correlation was observed between the BMI groups and the negative emotions, negative situations, and negative total scores of EMAQ (P < 0.01). The regression results on negative subscales showed that a one unit increase in BMI resulted in a 0.293 unit increase in negative situations scores, a 0.626 unit increase in negative emotions scores, and a 0.919 unit increase in negative total EMAQ scores. When the BMI groups and PEMS subscale scores were examined, a significant relationship was found in the social motives, rewarding, and conformity subscales (P < 0.01). A one unit increase in BMI increased the coping motives scores by 0.077 units.

CONCLUSIONS

The emotional states have a significant effect on the eating behavior. On the other hand, an increase in eating attacks was observed, particularly in people who were under the effect of a negative emotion or situation. Nevertheless, there were some limitations of the study in terms of quantitative determination of the effects of this eating behavior depending on the BMI.

Dietary Motivation and Hedonic Hunger Predict Palatable Food Consumption: An Intensive Longitudinal Study of Adolescents

Background

Understanding interactions between stable characteristics and fluctuating states underlying youth's food choices may inform methods for promoting more healthful food intake.

Purpose

This study examined dietary motivation and hedonic hunger as interacting predictors of adolescents' consumption of palatable foods.

Methods

Intensive longitudinal data were collected from 50 adolescents (aged 13-18) over 20 days. Participants completed a measure of dietary motivation at baseline and reported on hedonic hunger and palatable food consumption via a smartphone app at the end of each day.

Results

Results indicated that 66.7% of the variability in hedonic hunger was between-person (BP) and 33.3% was within-person (WP). BP hedonic hunger was positively associated with fatty food consumption (β = 0.28, p < .05), and WP hedonic hunger was positively associated with starchy food consumption (β = 0.38, p < .0001). Autonomous motivation was negatively associated with consumption of fast foods (β = -0.14, p < .05). Significant cross-level interactions were found: WP hedonic hunger and controlled motivation were positively associated with starchy food consumption, and WP hedonic hunger and autonomous motivation were negatively associated with fast food consumption.

Conclusions

Findings indicated that hedonic hunger has the potential to fluctuate, and conceptualization of the variable as both trait and state may be most appropriate. Adolescents with controlled dietary motivation may be vulnerable to the influence of hedonic hunger and prone to eating higher quantities of starchy foods. Adolescents with autonomous dietary motivation may be less vulnerable to hedonic hunger and less likely to consume fast food.

Hyper-Palatable Foods: Development of a Quantitative Definition and Application to the US Food System Database

OBJECTIVE

Extensive research has focused on hyper-palatable foods (HPF); however, HPF are defined using descriptive terms (e.g., fast foods, sweets), which are not standardized and lack specificity. The study purpose was to develop a quantitative definition of HPF and apply the definition to the Food and Nutrient Database for Dietary Studies (FNDDS) to determine HPF prevalence in the US food system.

METHODS

A numeric definition of HPF was developed by extracting common HPF descriptive definitions from the literature and using nutrition software to quantify ingredients of fat, simple sugars, carbohydrates, and sodium. The definition was applied to the FNDDS.

RESULTS

HPF from the literature aligned with three clusters: (1) fat and sodium (> 25% kcal from fat, ≥ 0.30% sodium by weight), (2) fat and simple sugars (> 20% kcal from fat, > 20% kcal from sugar), and (3) carbohydrates and sodium (> 40% kcal from carbohydrates, ≥ 0.20% sodium by weight). In the FNDDS, 62% (4,795/7,757) of foods met HPF criteria. The HPF criteria identified a variety of foods, including some labeled reduced or low fat and vegetables cooked in creams, sauces, or fats.

CONCLUSIONS

A data-derived HPF definition revealed that a substantial percentage of foods in the US food system may be hyper-palatable, including foods not previously conceptualized as hyper-palatable.

Expression of neural markers of gustatory signaling are differentially altered by continuous and intermittent feeding patterns

Food intake patterns are regulated by signals from the gustatory neural circuit, a complex neural network that begins at the tongue and continues to homeostatic and hedonic brain regions involved in eating behavior. The goal of the current study was to investigate the short-term effects of continuous access to a high fat diet (HFD) versus limited access to dietary fat on the gustatory neural circuit. Male Sprague-Dawley rats were fed a chow diet, a HFD (56% kcal from fat), or provided limited, daily (2 h/day) or limited, intermittent (2 h/day, 3 times/week) access to vegetable shortening for 2 weeks. Real time PCR was used to determine mRNA expression of markers of fat sensing/signaling (e.g. CD36) on the circumvallate papillae, markers of homeostatic eating in the mediobasal hypothalamus (MBH) and markers of hedonic eating in the nucleus accumbens (NAc). Continuous HFD increased mRNA levels of lingual CD36 and serotonin signaling, altered markers of homeostatic and hedonic eating. Limited, intermittent access to dietary fat selectively altered the expression of genes associated with the regulation of dopamine signaling. Overall, these data suggest that short-term, continuous access to HFD leads to altered fat taste and decreased expression of markers of homeostatic and hedonic eating. Limited, intermittent access, or binge-like, consumption of dietary fat led to an overall increase in markers of hedonic eating, without altering expression of lingual fat sensors or homeostatic eating. These data suggest that there are differential effects of meal patterns on gustatory neurocircuitry which may regulate the overconsumption of fat and lead to obesity.