Genetic and environmental influences on food preferences in adolescence

Missense genetic variants in major bitter taste receptors are associated with diet quality and food intake in a highly admixed underrepresented population

BACKGROUND AND AIMS

To investigate associations between Single Nucleotide Polymorphisms (SNPs) in the TAS1R and TAS2R taste receptors and diet quality, intake of alcohol, added sugar, and fat, using linear regression and machine learning techniques in a highly admixed population.

METHODS

In the ISA-Capital health survey, 901 individuals were interviewed and had socioeconomic, demographic, health characteristics, along with dietary information obtained through two 24-h recalls. Data on 12 components related to food groups, nutrients, and calories was combined into a diet quality score (BHEI-R). BHEI-R, SoFAAs (calories from added sugar, saturated fat, and alcohol) and Alcohol use were tested for associations with 255 TAS2R SNPs and 73 TAS1R SNPs for 637 individuals with regression analysis and Random Forest. Significant SNPs were combined into Genetic taste scores (GTSs).

RESULTS

Among 23 SNPs significantly associated either by stepwise linear/logistic regression or random forest with any possible biological functionality, the missense variants rs149217752 in TAS2R40, for SoFAAs, and rs2233997 in TAS2R4, were associated with both BHEI-R (under 4% increase in Mean Squared Error) and SoFAAs. GTSs increased the variance explanation of quantitative phenotypes and there was a moderately high AUC for alcohol use.

CONCLUSIONS

The study provides insights into the genetic basis of human taste perception through the identification of missense variants in the TAS2R gene family. These findings may contribute to future strategies in precision nutrition aimed at improving food quality by reducing added sugar, saturated fat, and alcohol intake.

Artificial intelligence driven definition of food preference endotypes in UK Biobank volunteers is associated with distinctive health outcomes and blood based metabolomic and proteomic profiles

BACKGROUND

Specific food preferences can determine an individual's dietary patterns and therefore, may be associated with certain health risks and benefits.

METHODS

Using food preference questionnaire (FPQ) data from a subset comprising over 180,000 UK Biobank participants, we employed Latent Profile Analysis (LPA) approach to identify the main patterns or profiles among participants. blood biochemistry across groups/profiles was compared using the non-parametric Kruskal-Wallis test. We applied the Limma algorithm for differential abundance analysis on 168 metabolites and 2923 proteins, and utilized the Database for Annotation, Visualization and Integrated Discovery (DAVID) to identify enriched biological processes and pathways. Relative risks (RR) were calculated for chronic diseases and mental conditions per group, adjusting for sociodemographic factors.

RESULTS

Based on their food preferences, three profiles were termed: the putative Health-conscious group (low preference for animal-based or sweet foods, and high preference for vegetables and fruits), the Omnivore group (high preference for all foods), and the putative Sweet-tooth group (high preference for sweet foods and sweetened beverages). The Health-conscious group exhibited lower risk of heart failure (RR = 0.86, 95%CI 0.79-0.93) and chronic kidney disease (RR = 0.69, 95%CI 0.65-0.74) compared to the two other groups. The Sweet-tooth group had greater risk of depression (RR = 1.27, 95%CI 1.21-1.34), diabetes (RR = 1.15, 95%CI 1.01-1.31), and stroke (RR = 1.22, 95%CI 1.15-1.31) compared to the other two groups. Cancer (overall) relative risk showed little difference across the Health-conscious, Omnivore, and Sweet-tooth groups with RR of 0.98 (95%CI 0.96-1.01), 1.00 (95%CI 0.98-1.03), and 1.01 (95%CI 0.98-1.04), respectively. The Health-conscious group was associated with lower levels of inflammatory biomarkers (e.g., C-reactive Protein) which are also known to be elevated in those with common metabolic diseases (e.g., cardiovascular disease). Other markers modulated in the Health-conscious group, ketone bodies, insulin-like growth factor-binding protein (IGFBP), and Growth Hormone 1 were more abundant, while leptin was less abundant. Further, the IGFBP pathway, which influences IGF1 activity, may be significantly enhanced by dietary choices.

CONCLUSIONS

These observations align with previous findings from studies focusing on weight loss interventions, which include a reduction in leptin levels. Overall, the Health-conscious group, with preference to healthier food options, has better health outcomes, compared to Sweet-tooth and Omnivore groups.

Nutritional status and dietary habits in older adults with fixed implant dental prostheses: a case-control study

Aim

To evaluate the nutritional status, nutritional risk, and dietary habits of patients treated with bimaxillary implant-supported fixed prostheses in comparison with a group of natural dentate patients.

Methods

A study group (n = 25, 8 women, mean age = 70.6 ± 7.5 years) with bimaxillary implant-supported fixed prostheses and a control group (n = 25, 13 women, mean age = 69.0 ± 5.3) with a mean of 27.7 ± 1.8 natural teeth were recruited. The nutritional status and nutritional risk of the participants were evaluated with Mini Nutritional Assessment (MNA) and Seniors in the Community: Risk Evaluation for Eating and Nutrition; (SCREEN-14), while the dietary habits were recorded by data from a three-day dietary record. The data were analyzed with the Mann-Whitney U-test and independent t-test to evaluate the differences between the groups.

Results

The results showed that although both the groups had normal nutrition status as revealed by the MNA scores the study group showed significantly higher BMI (p = 0.005) but lower SCREEN-14 (p = 0.012) scores, than the control group. The results also showed that higher SCREEN-14 scores were significantly associated with higher odds of being in the control group, with an odds ratio of 1.159 (p = 0.024). Further, the results of the analysis of the dietary records showed that the participants in the study group consumed fewer meals (p = 0.006) and fewer varieties of food (p < 0.001), particularly fewer fruits (p = 0.011) than the control group.

Conclusion

The results indicate that people with fixed implant prostheses may be susceptible to nutritional deficiencies according to the SCREEN-14 scores compared to their natural dentate counterparts. Further, people with implant prostheses also tend to have higher BMI and consume a smaller variety of foods, especially fruits, than the natural dentate control group.

Nature and nurture in fussy eating from toddlerhood to early adolescence: findings from the Gemini twin cohort

BACKGROUND

Food fussiness (FF) describes the tendency to eat a small range of foods, due to pickiness and/or reluctance to try new foods. A common behaviour during childhood, and a considerable cause of caregiver concern; its causes are poorly understood. This is the first twin study of genetic and environmental contributions to the developmental trajectory of FF from toddlerhood to early adolescence, and stability and change over time.

METHODS

Participants were from Gemini, a population-based British cohort of n = 4,804 twins born in 2007. Parents reported on FF using the Child Eating Behaviour Questionnaire 'FF' scale when children were 16 months (n = 3,854), 3 (n = 2,666), 5 (n = 2,098), 7 (n = 703), and 13 years old (n = 970). A mixed linear model examined the trajectory of FF, and a correlated factors twin model quantified genetic and environmental contributions to variation in and covariation between trajectory parameters. A longitudinal Cholesky twin model examined genetic and environmental influences on FF at each discrete age.

RESULTS

We modelled a single FF trajectory for all children, which was characterised by increases from 16 months to 7 years, followed by a slight decline from 7 to 13 years. All trajectory parameters were under strong genetic influence (>70%) that was largely shared, indicated by high genetic correlations. Discrete age analyses showed that genetic influence on FF increased significantly after toddlerhood (16 months: 60%, 95% CI: 53%-67%; 3 years: 83%; 81%-86%), with continuing genetic influence as indicated by significant genetic overlap across every age. Shared environmental influences were only significant during toddlerhood. Unique environmental influences explained 15%-26% of the variance over time, with some enduring influence from 5 years onwards.

CONCLUSIONS

Individual differences in FF were largely explained by genetic factors at all ages. Fussy eating also shows a significant proportion of environmental influence, especially in toddlerhood, and may, therefore, benefit from early interventions throughout childhood. Future work needs to refine the FF trajectory and explore specific trajectory classes.

Genetically predicted dietary intake and risks of colorectal cancer: a Mendelian randomisation study

BACKGROUND

Effects of confounders on associations between diet and colorectal cancer (CRC) in observational studies can be minimized in Mendelian randomization (MR) approach. This study aimed to investigate observational and genetically predicted associations between dietary intake and CRC using one-sample MR.

METHODS

Using genetic data of over 93 million variants, we performed a genome-wide association study to find genomic risk loci associated with dietary intake in participants from the UK Biobank. Then we calculated genetic risk scores of diet-related variants and used them as instrumental variables in the two-stage least square MR framework to estimate the hazard ratios (HRs) and 95% confidence intervals (CIs) for associations. We also performed observational analyses using age as a time-scale in Cox proportional hazard models.

RESULTS

Allele scores were calculated from 399 genetic variants associated with the consumption of of red meat, processed meat, poultry, fish, milk, cheese, fruits, vegetables, coffee, tea, and alcohol in participants from the UK Biobank. In MR analysis, genetically predicted fruit intake was significantly associated with a 21% decreased risk of CRC (HR = 0.79, 95% CI = 0.66-0.95), and there was a marginally inverse association between vegetable intake and CRC (HR = 0.85, 95% CI = 0.71-1.02). However, null findings were observed in multivariable analysis, with HRs (95% CIs) of 0.99 (0.98-1.01) and 0.99 (0.98-1.00) per increment of daily servings of fruits and vegetables, respectively.

CONCLUSION

Dietary habits were attributable to genetic variations, which can be used as instrumental variables in the MR framework. Our study supported a causal relationship between fruit intake and a decreased risk of CRC and suggested an effective strategy of consuming fruits in the primary prevention of CRC.

Food Neophobias in Spanish Adults with Overweight or Obesity by Sex: Their Association with Sociodemographic Factors and the Most Prevalent Chronic Diseases

Food neophobia has been defined as the reluctance to try new foods. Food neophobia is common in children and older people, but until now, scarce research has been carried out on food neophobia in the adult population. The aim of this study was to assess the most usual food neophobias in Spanish adults with overweight and obesity by sex, and their association with sociodemographic factors and the most prevalent chronic diseases. A cross-sectional observational study was carried out on adults (mean age of 43.5 ± 13.7 years old; n = 590; 50% female) with overweight or obesity. Their anthropometrics, adherence to the Mediterranean diet, age, educational level, economic level, smoking and sleeping habits, physical activity, chronic diseases, and food neophobias were assessed. The highest food neophobias in Spanish adults with overweight or obesity were directed toward vegetables, meat, fish, pulses, game meat, and fruits, mostly among females, with differences between sexes. Phobias of the soft texture of foods were also observed, without differences between sexes. Age, educational level, sleeping habits, and physical activity were directly related, and economical level and smoking were inversely related to food neophobia, mainly to healthy foods, and more obvious in males than in females. There were associations between body mass index (BMI) and chronic diseases and food neophobia. Adherence to the adaption of healthy and sustainable diets is low within food neophobics, increasing the risk of diet-related chronic diseases.

Validity and reliability of the Persian version of food preferences questionnaire (Persian-FPQ) in Iranian adolescents

The assessment of dietary intakes and habits using reliable and youth-specific measurement tools during adolescence is essential. The aim of the present study was to culturally adapt and investigate the psychometric properties of the Persian version of the food preferences questionnaire (Persian-FPQ) among Iranian adolescents. This methodological cross-sectional study was conducted among 452 Persian-speaking adolescents, living in Isfahan, Iran. Translation of the FPQ was performed using forward-backward method. Intra Class Correlation (ICC) and Cronbach's α were used to assess test-retest reliability and internal consistency, respectively. Construct validity was investigated by using exploratory factor analysis (EFA). Divergent validity was determined using correlation analysis with Kessler Psychological Distress Scale (K-10). Known-group validity was assessed based on differences in mean food preference score between boys and girls and different categories of body mass index (BMI). The internal and external reliabilities for the Persian-FPQ were in the range of good to excellent in all domains (Cronbach's α: 0.76-0.96 and ICCs: 0.982-0.998). Boys had higher scores of food preferences than girls, indicating good known-group validity. Construct validity evaluated by EFA led to extraction of seven factors ("Vegetables", "Fruit", "Dairy", "Snacks", "Meat/Fish", "Starches" and "Miscellaneous foods"), explaining 37.8% of the variance. Divergent validity revealed significant negative correlations between five sub-scales of the Persian-FPQ and psychological distress. The Persian version of the FPQ is a reliable and valid instrument with applicability in a broad range of the population of Persian-speaking adolescents for assessing food preferences in community-based research projects.

Is food preference innate instinct driven or human's free will?

The question whether food preference decisions are controlled by innate instincts, or a conscious decision-making process is still open. The answer to this question is important not only for neuroscientists, psychologists, and philosophers but also for food scientists and developers. Looking from different perspectives involved in food preference decisions could not only settle a long ongoing debate but also pave the way to understand why people prefer to eat what they eat.

Frequency of Consumption of Food Groups and Cardio-Metabolic Risk Factors: A Genetically Informative Twin Study in Sri Lanka

Low- and middle-income countries (LMICs) globally have undergone rapid urbanisation, and changes in demography and health behaviours. In Sri Lanka, cardio-vascular disease and diabetes are now leading causes of mortality. High prevalence of their risk factors, including hypertension, dysglycaemia and obesity have also been observed. Diet is a key modifiable risk factor for both cardio-vascular disease and diabetes as well as their risk factors. Although typically thought of as an environmental risk factor, dietary choice has been shown to be genetically influenced, and genes associated with this behaviour correlate with metabolic risk indicators. We used Structural Equation Model fitting to investigate the aetiology of dietary choices and cardio-metabolic phenotypes in COTASS, a population-based twin and singleton sample in Colombo, Sri Lanka. Participants completed a Food Frequency Questionnaire (N = 3934) which assessed frequency of intake of 14 food groups including meat, vegetables and dessert or sweet snacks. Anthropometric (N = 3675) and cardio-metabolic (N = 3477) phenotypes were also collected including weight, blood pressure, cholesterol, fasting plasma glucose and triglycerides. Frequency of consumption of most food items was found to be largely environmental in origin with both the shared and non-shared environmental influences indicated. Modest genetic influences were observed for some food groups (e.g. fruits and leafy greens). Cardio-metabolic phenotypes showed moderate genetic influences with some shared environmental influence for Body Mass Index, blood pressure and triglycerides. Overall, it seemed that shared environmental effects were more important for both dietary choices and cardio-metabolic phenotypes compared to populations in the Global North.

Genetics of vegetarianism: A genome-wide association study

A substantial body of evidence points to the heritability of dietary preferences. While vegetarianism has been practiced for millennia in various societies, its practitioners remain a small minority of people worldwide, and the role of genetics in choosing a vegetarian diet is not well understood. Dietary choices involve an interplay between the physiologic effects of dietary items, their metabolism, and taste perception, all of which are strongly influenced by genetics. In this study, we used a genome-wide association study (GWAS) to identify loci associated with strict vegetarianism in UK Biobank participants. Comparing 5,324 strict vegetarians to 329,455 controls, we identified one SNP on chromosome 18 that is associated with vegetarianism at the genome-wide significant level (rs72884519, β = -0.11, P = 4.997 x 10-8), and an additional 201 suggestively significant variants. Four genes are associated with rs72884519: TMEM241, RIOK3, NPC1, and RMC1. Using the Functional Mapping and Annotation (FUMA) platform and the Multi-marker Analysis of GenoMic Annotation (MAGMA) tool, we identified 34 genes with a possible role in vegetarianism, 3 of which are GWAS-significant based on gene-level analysis: RIOK3, RMC1, and NPC1. Several of the genes associated with vegetarianism, including TMEM241, NPC1, and RMC1, have important functions in lipid metabolism and brain function, raising the possibility that differences in lipid metabolism and their effects on the brain may underlie the ability to subsist on a vegetarian diet. These results support a role for genetics in choosing a vegetarian diet and open the door to future studies aimed at further elucidating the physiologic pathways involved in vegetarianism.

Analysis of Determinants of Food Preferences in a Polish Population-Based Sample of Primary School Adolescents: Diet and Activity of Youth during COVID-19 (DAY-19) Study

For the choices of food products, food preferences are crucial, as they influence the intake of nutrients and the resultant quality of diet, but in Poland, no studies of food preferences were conducted during the COVID-19 pandemic on a population of young adolescents. The aim of this study was to analyze the determinants of food preferences in a Polish population-based sample of primary school adolescents as part of the Diet and Activity of Youth during COVID-19 (DAY-19) Study. The DAY-19 Study focused on a national sample of a population of primary school adolescents who were recruited based on cluster sampling of participants from counties and schools, yielding a sample of 5039 individuals. Their food preferences were assessed using the Food Preference Questionnaire (FPQ), and they were compared in subgroups stratified by (1) gender: male and female; (2) age: younger (10-13 years) and older (14-16 years); (3) place of residence: urban and rural; (4) Body Mass Index (BMI): underweight, normal body weight, and overweight/obese (assessed based on Polish growth reference values); and (5) physical activity level: low and moderate (assessed using the International Physical Activity Questionnaire for children aged 10-13 (IPAQ-C) and adolescents aged 14-16 (IPAQ-A)). In the population of adolescents, no statistically significant differences in food preferences between subgroups stratified by gender were observed (p > 0.05). For boys, none of the studied factors (age, place of residence, BMI, physical activity level) was statistically significant determinant of food preferences (p < 0.05), while for girls, all of them were statistically significant determinants (p > 0.05). All the assessed factors (age, place of residence, BMI, physical activity level) in girls were associated with preferences for snacks, and older girls, those from a rural environment, those who were underweight and overweight/obese, as well as those having a low physical activity level declared a higher preference for snacks than younger ones (p = 0.0429), those from an urban environment (p = 0.0484), those of a normal body weight (p = 0.0091), and those having a moderate physical activity level (p = 0.0083). Similarly, girls from rural environments declared a higher preference for starches than those from urban environments (p = 0.0103), and girls having a low physical activity level declared a higher preference for fruit than those having a moderate physical activity level (p = 0.0376). Taking this into account, the population of girls, in particular, needs dedicated educational actions to support proper nutritional habits. Additionally, older age, living in a rural environment, being underweight and overweight/obese, and having a low physical activity level may be indicated as factors predisposing one to food preferences potentially promoting unhealthy dietary habits.

Genetic and environmental influences on fruit and vegetable consumption and depression in older adults

BACKGROUND

Prior work suggests that higher fruit and vegetable consumption may protect against depression in older adults. Better understanding of the influence of genetic and environmental factors on fruit and vegetable intakes may lead to the design of more effective dietary strategies to increase intakes. In turn this may reduce the occurrence of depression in older adults.

OBJECTIVES

The primary aim of this study is to estimate the genetic and environmental influences on the consumption of fruit and vegetables in older adults. The secondary aim is an exploratory analysis into possible shared genetic influences on fruit and vegetable intakes and depression.

METHODS

Analysis of observational data from 374 twins (67.1% female; 208 monozygotic (MZ); 166 dizygotic (DZ)) aged ≥ 65 years drawn from the Older Australian Twins Study. Dietary data were obtained using a validated food frequency questionnaire and depressive symptoms were measured using the 15-item short form Geriatric Depression Scale. The contribution of genetic and environmental influences on fruit and vegetable intake were estimated by comparing MZ and DZ twin intakes using structural equation modelling. A tri-variate twin model was used to estimate the genetic and environmental correlation between total fruit and vegetable intakes and depression.

RESULTS

In this study, vegetable intake was moderately influenced by genetics (0.39 95%CI 0.22, 0.54). Heritability was highest for brassica vegetables (0.40 95%CI 0.24, 0.54). Overall fruit intake was not significantly heritable. No significant genetic correlations were detected between fruit and vegetable intake and depressive symptoms.

CONCLUSIONS

Vegetable consumption, particularly bitter tasting brassica vegetables, was significantly influenced by genetics, although environmental influences were also apparent. Consumption of fruit was only influenced by the environment, with no genetic influence detected, suggesting strategies targeting the food environment may be particularly effective for encouraging fruit consumption.

Are problematic eating behaviors from 4- to 7-year-old explained by genetic, shared factors or individual characteristics? A longitudinal twin study

Studies based on twins are ideal to disentangle the relative contribution of different factors in the development of eating behaviors. This study aims to evaluate if changes in problematic eating behaviors from 4 to 7 years old are more influenced by the genetics, the shared environment of twins, or by individual characteristics of each twin. A total of 86 caregivers (mostly mothers) of twins from the Generation XXI birth cohort provided information on eating behaviors at 4 and 7 years of age. A score of problematic eating behaviors was developed. The Common fate model and the ACE model were used to estimate the effect of shared, individual, and genetic characteristics on changes in eating behaviors. At the dyadic level (shared), the eating behavior score at 4 years old was significantly and positively associated with the eating behavior at 7 years of age (β = 0.402, 95% CI 0.063;0.657). At the individual level, no significant association was observed (β = 0.020, 95% CI -0.078;0.125). The ACE model also showed the shared environment as the major responsible for the changes in eating behaviors from 4 to 7 years old. It also showed that genetic characteristics decreased their relevance overtime. This study supports that changes in eating behaviors from 4 to 7 years of age are mostly associated with the shared environment rather than individual characteristics of each twin. These results are important to improve future strategies to promote healthy environments.

Effect of School-Based Food and Nutrition Education Interventions on the Food Consumption of Adolescents: A Systematic Review and Meta-Analysis

The school is a favorable environment for the development of interventions to prevent obesity. The objective of this systematic review is to evaluate the effects of school-based food and nutrition education interventions on adolescent food consumption. The literature search was conducted on databases: MEDLINE/PubMed, Embase, Scopus, ERIC, Science Direct, Web of Science, Cochrane, LILACS, and ADOLEC. The following research strategies were focused on: population (adolescents), intervention (food and nutrition education), outcome (food consumption), and study design (clinical trial). The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement guidelines were followed and all stages of this review were performed by two researchers and, when necessary, a third researcher resolved discrepancies. Included studies are randomized clinical trials (RCT). A total of 24 articles were included for review and 11 articles in meta-analysis. In the evaluation of the general effects, there was a significant effect (mean difference (MD) for fruit consumption (MD = 0.09, CI 0.05, 0.14) in serving/day; and for vegetables (MD = 0.59, IC 0.15, 1.03) at times/week. In the consumption of FV (fruits and vegetables), there was no significant effect (standardized mean difference (SMD) of interventions in their consumption (SMD = 0.00, 95% C1 -0.11, 0.11). The evidence available in this review and meta-analysis concludes that food and nutrition education interventions in schools presented favorable results in the food consumption of adolescents. Registered on the PROSPERO database (CRD42019116520).

Shared familial risk factors between autism spectrum disorder and obesity - a register-based familial coaggregation cohort study

BACKGROUND

Meta-analyses suggest an association between autism spectrum disorder (ASD) and obesity, but the factors underlying this association remain unclear. This study investigated the association between ASD and obesity stratified on intellectual disability (ID). In addition, in order to gain insight into possible shared etiological factors, the potential role of shared familial liability was examined.

METHOD

We studied a cohort of 3,141,696 individuals by linking several Swedish nationwide registers. We identified 35,461 individuals with ASD and 61,784 individuals with obesity. Logistic regression models were used to estimate the association between ASD and obesity separately by ID and sex and by adjusting for parental education, psychiatric comorbidity, and psychotropic medication. Potential shared familial etiologic factors were examined by comparing the risk of obesity in full siblings, maternal and paternal half-siblings, and full- and half-cousins of individuals with ASD to the risk of obesity in relatives of individuals without ASD.

RESULTS

Individuals with ASD + ID (OR = 3.76 [95% CI, 3.38-4.19]) and ASD-ID (OR = 3.40 [95% CI, 3.23-3.58]) had an increased risk for obesity compared with individuals without ASD. The associations remained statistically significant when adjusting for parental education, psychiatric comorbidity, and medication. Sex-stratified analyses indicated a higher relative risk for males compared with females, with statistically significant interaction effects for ASD-ID, but not for ASD+ID in the fully adjusted model. First-degree relatives of individuals with ASD+ID and ASD-ID had an increased risk of obesity compared with first-degree relatives of individuals without ASD. The obesity risk was similar in second-degree relatives of individuals with ASD+ID but was lower for and ASD-ID. Full cousins of individuals with ASD+ID had a higher risk compared with half-cousins of individuals with ASD+ID). A similar difference in the obesity risk between full cousins and half-cousins was observed for ASD-ID.

CONCLUSIONS

Individuals with ASD and their relatives are at increased risk for obesity. The risk might be somewhat higher for males than females. This warrants further studies examining potential common pleiotropic genetic factors and shared family-wide environmental factors for ASD and obesity. Such research might aid in identifying specific risks and underlying mechanisms in common between ASD and obesity.

Large-scale GWAS of food liking reveals genetic determinants and genetic correlations with distinct neurophysiological traits

We present the results of a GWAS of food liking conducted on 161,625 participants from the UK-Biobank. Liking was assessed over 139 specific foods using a 9-point scale. Genetic correlations coupled with structural equation modelling identified a multi-level hierarchical map of food-liking with three main dimensions: "Highly-palatable", "Acquired" and "Low-caloric". The Highly-palatable dimension is genetically uncorrelated from the other two, suggesting that independent processes underlie liking high reward foods. This is confirmed by genetic correlations with MRI brain traits which show with distinct associations. Comparison with the corresponding food consumption traits shows a high genetic correlation, while liking exhibits twice the heritability. GWAS analysis identified 1,401 significant food-liking associations which showed substantial agreement in the direction of effects with 11 independent cohorts. In conclusion, we created a comprehensive map of the genetic determinants and associated neurophysiological factors of food-liking.

Diet quality comparisons in Hispanic/Latino siblings: Results from the Hispanic Community Children's Health Study/Study of Latino Youth (SOL Youth)

The objective of this study was to determine how well Hispanic/Latino siblings' diet quality correlate with each other and whether social and environmental factors explained potential differences. Hispanic/Latino 8-16-year-olds from the cross-sectional Hispanic Community Children's Health Study/Study of Latino Youth (SOL Youth) with at least one sibling enrolled in the study were examined (n = 740). Diet quality was assessed with the Healthy Eating Index 2010 (HEI-2010), calculated from two 24-h recalls. Mixed effects models were used with HEI-2010 score as the outcome, and correlations in siblings' diet quality were assessed with intraclass correlation coefficients (ICCs). All models were examined stratified by age and sex. Diet-related social and environmental measures were added as fixed effects in a secondary analysis. Mean (standard deviation) overall HEI-2010 score was 53.8 (13.0). The ICC for siblings' HEI-2010 score was 0.31 (95% CI: 0.25, 0.38). Siblings who were born <3 vs. ≥3 years apart had stronger correlations in overall diet quality (0.47 [95% CI: 0.37, 0.58] vs. 0.21 [95% CI: 0.13, 0.30]), but no differences were observed in overall HEI-2010 score according to sex. Greater peer support for fruit and vegetable intake (β = 1.42 [95% CI: 0.62, 2.21]) and greater away-from-home food consumption (β = -1.24 [95% CI: -2.15, -0.32]) were associated with differences in siblings' diet quality. Overall diet quality scores of Hispanic/Latino siblings in this study were slightly correlated, with stronger correlations among siblings closer in age. Differences in peer support and foods consumed outside the home may explain differences in siblings' diet quality. Future research should investigate additional determinants of differences in siblings' diets.

Association of the dopamine D2 receptor rs1800497 polymorphism with food addiction, food reinforcement, and eating behavior in Chilean adults

PURPOSE

The regulation of food intake and body weight involves two interacting systems: (a) The homeostatic system (including biological regulators of hunger and satiety) and (b) the non-homeostatic system, (involving concepts of food reinforcement and food addiction). Studies have established a strong genetic component in eating behavior and obesity. The TaqI A1 polymorphism (rs1800497) has previously been associated with eating behavior, diminished dopamine D2 receptor (DRD2) density, higher body mass, and food reinforcement, but relations to food addiction remain unclear.

AIM

To evaluate the association between the polymorphism rs1800497 with eating behavior, food reinforcement and food addiction in Chilean adults.

METHODS

This cross-sectional study recruited a convenience sample of 97 obese, 25 overweight and 99 normal-weight adults (18-35 years). Anthropometric measurements were performed by standard procedures. Eating behavior was assessed using the: Yale Food Addiction Scale (YFAS), the Three Factor Eating Behavior Questionnaire and the Food Reinforcement Value Questionnaire (FRVQ). The DRD2 genotype (rs1800497) was determined by taqman assays.

RESULTS

Twenty-two percentage of the participants met the criteria for food addiction. Food addiction was higher in women than men (26% vs 10.7%) and in obese compared to non-obese (40% vs 6%). There was no relationship between food addiction and DRD2 genotype. However when stratified by sex and nutritional status, obese female carriers of the A1 allele reported greater scores on emotional eating and snack food reinforcement compared to non-carriers.

CONCLUSIONS

The DRD2 polymorphism is associated with some hedonic aspects of eating behavior, namely food reinforcement and emotional eating but not food addiction, and this association may be moderated by sex and obesity status, with obese women who are carriers of this genetic variant at higher risk.

LEVEL OF EVIDENCE

Level V: evidence obtained from a cross-sectional descriptive study.

Association between Food Preferences and Food Habits in a Polish Adolescents' COVID-19 Experience (PLACE-19) Study

Food preferences are among the most influential factors of food habits in the vulnerable period of adolescence; in addition, gender-dependent differences in food preferences are also observed. The aim of the present study was to analyze differences in food habits between individuals stratified based on their food preferences in a population-based sample of adolescents aged 15–20. The study was conducted within the Polish Adolescents’ COVID-19 Experience (PLACE-19) Study population in a group of 2419 secondary school students who were randomly chosen to participate in the study using a random quota sampling procedure. The food preferences were determined on the basis of a validated Food Preference Questionnaire (FPQ) (which enables assessing preference of vegetables, fruit, meat/fish, dairy, snacks, and starches), whereas food habits were determined on the basis of the Adolescents’ Food Habits Checklist (AFHC) (which enables assessing food purchase, preparation, and consumption habits). The analysis involved three homogenous clusters (‘low-preferring’, ‘hedonists’, and ‘high-preferring’), which were identified using the k-means algorithm. It was found that for a number of the assessed food purchase, preparation, and consumption habits, there were statistically significant differences between the ‘low-preferring’, ‘hedonists’, and ‘high-preferring’ clusters. Within food purchase habits, the food preference influenced frequency of buying pastries/cakes and frequency of eating takeaway meals for all the respondents, while for female respondents, it influenced also choice of desserts in restaurants, and for male respondents, it influenced choosing a low-fat lunch away from home (p < 0.05). Within food preparation habits, the food preference influenced the fat content in desserts at home, the frequency of eating at least one serving of vegetables/salad with an evening meal, the frequency of spreading butter/margarine on bread thinly, and the frequency of having cream on desserts for all the respondents; meanwhile, for female respondents, it also influenced the frequency of avoiding fried foods and the frequency of including chocolate/biscuits in their packed lunch (p < 0.05). Within food consumption habits, the food preference influenced the frequency of eating a dessert/pudding, eating at least one serving of fruit a day, eating at least one serving of vegetables/salad a day, avoiding sausages/burgers, trying to ensure they eat plenty of fruit and vegetables, and frequency of choosing fruit as a snack for all the respondents; meanwhile, for male respondents, it also influenced the frequency of eating sweet snacks and eating at least three servings of fruit most days (p < 0.05). Taking into account that some improper food habits may be typical for the specific clusters, there is an urgent need to analyze and address them for the purposes of public health and to bear in mind that some of those habits are gender-dependent.

Food Preferences and Food Choice Determinants in a Polish Adolescents' COVID-19 Experience (PLACE-19) Study

Food preferences are within the most important determinants of food choices; however, little is known about their complex associations, and no studies were conducted in the period of the COVID-19 pandemic. The aim of the study was to analyze the association between food preferences and food choice determinants in adolescents aged 15-20 years within the Polish Adolescents' COVID-19 Experience (PLACE-19) Study. The PLACE-19 Study included a random quota sampling conducted in the whole of Poland and covered a population-based sample of 2448 secondary school students. The food preferences were assessed using a validated Food Preference Questionnaire (FPQ), and the food choices were assessed using a validated Food Choice Questionnaire (FCQ). The statistical analysis comprised k-means clustering and linear regression adjusted for sex and age. Four homogenous clusters of respondents were defined based on the food choice motives-"healthy eaters" (health as the most important determinant of food choices), "hedonists" (convenience, sensory appeal, and price as the most important determinants), "indifferent consumers" (low significance for all determinants), and "demanding consumers" (high significance for all determinants). The preferences for all food categories differed when comparing between clusters presenting various food choice determinants (p < 0.001). The "healthy eaters" were characterized by the highest preference for vegetables; the "hedonists" preferred meat/fish, dairy, and snacks; the "demanding consumers" had a high preference for all food categories, while "indifferent consumers" had a low preference for all food categories. All preference scores were positively associated with mood, convenience, sensory appeal, natural content, and price (p < 0.05). The results confirmed the association between food preferences and food choice determinants in adolescents, as well as allowed adolescents to be clustered into segments to define various needs and motives among the identified segments. For public health purposes, it may be crucial to educate "hedonists," with a high preference for meat/fish, dairy and snacks, accompanied by convenience, sensory appeal, and price as the most important determinants of their food choices.

Associations between Food Preferences, Food Approach, and Food Avoidance in a Polish Adolescents' COVID-19 Experience (PLACE-19) Study Population

Food preferences are among the strongest predictors of the food choices of adolescents. These are associated with appetitive traits (food approach and avoidance) to some extent. However, no research has been conducted so far analyzing the association between food preferences and appetitive traits of adolescents. The aim of this study was to evaluate the associations between food preferences and appetitive traits in adolescents (aged 15-20 years) within the Polish Adolescents' COVID-19 Experience (PLACE-19) Study population. The PLACE-19 Study was carried out in a population-based sample of 2448 secondary school students sampled across the country (random quota sampling). Food preferences (including the preference for vegetables, fruit, meat/fish, dairy, snacks, and starches) of the adolescents were assessed using the validated Food Preference Questionnaire (FPQ) while their appetitive traits (hunger, food responsiveness, emotional overeating, enjoyment of food, satiety responsiveness, emotional undereating, food fussiness, slowness in eating) were assessed using the validated Adult Eating Behavior Questionnaire (AEBQ). The k-means clustering was performed to identify the homogenous clusters of respondents based on their preferences, and linear regression was performed to determine the relationship between food preferences and appetitive traits with a model adjusted for sex and age. Based on their preferences, three homogenous clusters of respondents were defined: low-preferring respondents (low preference for all food categories), respondents preferring snacking foods (low preference for all food categories, except for fruit and snacks), and high-preferring respondents (high preference for all food categories). The low-preferring respondents showed the lowest values for all appetitive traits (p = 0.0008), as well as the lowest total score (p = 0.0001), except for food fussiness, for which they showed the highest value (p = 0.0008). All preference scores were positively associated with traits such as hunger, food responsiveness, enjoyment of food, and emotional under-eating, while negatively associated with food fussiness (all p < 0.05). The largest amount of variance was observed for preference for dairy (14.6%; R² = 0.146, p = 0.008) and snacks with respect to enjoyment of food (16.2%; R² = 0.162, p = 0.008), for vegetable with respect to food fussiness (22%; R² = 0.220, p = 0.008), and for meat/fish with respect to enjoyment of food (19.9%; R² = 0.199, p = 0.008) and food fussiness combined (19.1%; R² = 0.191, p = 0.008). These results support the association of food preferences with both food approach traits and food avoidance traits.

Efficacy of a smartphone application-based intervention for encouraging children's healthy eating in Denmark

The growing rates of childhood obesity constitute a public health challenge worldwide. Therefore it is important to identify effective and widely applicable interventions to prevent it. This study aims to explore children's experience of using a newly developed smartphone application (app) designed to promote healthy eating and evaluate its efficacy on encouraging healthy eating. First, two focus groups were conducted to explore children's experience of using the app. Then, a quasi-experimental design was used to evaluate the app's efficacy. The children were asked to use the app for three months. Afterwards, the effect of the intervention was evaluated. 118 children aged 9 to 13 years (M=10.9, Sd=1.1) participated in the study. The children's experience of using the app was relatively positive, and they found the app easy to use. A significant increase in fruit (η2=.10) and vegetable preferences (η2=.37) and fruit intake (η2=.06) was found in the experimental group. No effects were found for vegetable intake, selfefficacy for healthy eating, or peer norms for healthy and unhealthy eating (p>0.05). The smartphone app-based intervention could potentially serve as an attractive and low-cost intervention to reach a wide population of children for the promotion of healthy eating and prevention of childhood obesity.

Food preferences, food neophobia and chemosensation among adolescents with ADHD

AIM

It has been suggested that adolescents diagnosed with ADHD have an unhealthier diet compared to their peers without ADHD. The association between chemosensation (smell and taste) and dietary patterns remains unknown. The aim is to investigate unhealthy food preferences and food neophobic behaviour among adolescents diagnosed with ADHD. Additionally, it is to investigate the relationship between dietary patterns and chemosensory function.

METHODS

We enrolled 36 adolescents with and without ADHD to complete a food item and a food neophobia questionnaire and to undergo chemosensory testing.

RESULTS

Adolescents with ADHD performed significantly worse on both chemosensory tests compared to the non-ADHD group. No difference in food preferences nor food neophobia was found between the two groups.

CONCLUSION

Adolescents with ADHD have a lower score on chemosensory tests compared to their peers, suggesting impaired chemosensory function. No differences in dietary preferences nor food neophobia were seen between the two groups.

Nutrigenomics reveals potential genetic underpinning of diverse taste preference of Chinese men

BACKGROUND

Taste preference varies geographically in China. However, studies on Chinese people's taste preference in different regions of China are limited, and are lack of research on the mechanism of differences in taste preference, especially in genetics.

OBJECTIVE

This study aims to investigate the characteristics of taste preference of Chinese men, and estimate whether diverse taste preference in Chinese have genetic underpinning.

METHODS

We conducted a questionnaire survey on taste preferences on 1076 males from 10 regions of China, and collected another 1427 males from the same regions which genotyped by microarray. We compared the correlation between different taste preference, and evaluated the correlation between the mutation frequency of inhouse database and different taste preference. The putative taste-preference-related genes were further utilized to estimate the candidate relationship on gene and gene network in different taste preference.

RESULTS

There was a correlation between different taste preferences in Chinese men. We found 31 SNPs associated with 6 kind of taste preferences. These SNPs located within or nearby 36 genes, and the tastes associated with 4 of these genes (TRPV1, AGT, ASIC2 and GLP1R) are consistent with the previous studies. Moreover, in different tastes which were suggested to be associated with each other, some putative related genes were the same or in the same gene network, such as pathways related with blood pressure, response to stimulus and nervous system.

CONCLUSIONS

This study indicates that the diverse taste preference of Chinese men may have genetic underpinning.

Association of single nucleotide polymorphisms with taste and food preferences of the Hungarian general and Roma populations

It is reasonable to suppose that poor diet underlies the unfavorable health status of the Roma population of Europe. Previously in the framework of a complex health survey, fruit and vegetable consumption, quantity of sugar added, salting frequency; bitter, salty, sweet and fat taste preferences were evaluated of Hungarian (HG, n = 410) and Roma (HR, n = 387) populations. In the present study the associations of taste and food preferences with TAS1R3, CD36, SCNN1B, TRPV1, TAS2R38, TAS2R19 and CA6 polymorphisms were tested in the same samples. Genotype frequencies did not differ significantly between the two populations. Although we initially observed associations between certain genetic polymorphisms and taste and food preferences in our study samples, none of the p values remained significant after the multiple test correction. However, some of our results could be considered promising (0.05<corrected p < 0.20), which showed potential ethnicity-specific effects (CA6 rs2274333 with salty taste and raw kohlrabi preference, CD36 rs1527483 with fat taste preference, TAS2R19 rs10772420 with grapefruit preference, and TAS2R38 rs713598 with quantity of sugar added). Our results may suggest that genetics may mediate food preferences, and individuals with different ethnic background may require personalized interventions to modify diet. Further investigations with greater sample sizes are essential to explore the effect of these genetic variants on taste and food preferences.

Positive association between bitter taste threshold and preference of vegetables among adolescents

AIM

Better understanding of aspects of taste in adolescents is needed since it has bearings on food policies, food industry and pharmaceutical design. Furthermore, taste preferences likely play a role in overeating and anorexia. We aimed to validate a questionnaire about taste preferences and dietary habits along with measurements of sense of smell and taste.

METHODS

We included adolescents from nearby schools in Aarhus, Denmark, from 2017 to 2019. Scoring preferences and habits on a Likert scale, they completed a food item questionnaire. Their chemosensation was tested by the Sniffin' Sticks and Taste Drop Test.

RESULTS

We included 100 adolescents: 53 males, 47 females; average age: 15.9 years (12-17 years). Retest of the questionnaire showed good reliability (Cohen's kappa: 0.5953). Snacks scored the highest average liking (4.48), whereas starches had the highest frequency of consumption (3.64). Bitter taste threshold was positively associated with liking and familiarity with vegetables (P = .032; P = .012), respectively. Healthy self-reported dietary habits were associated with a higher self-reported consumption of vegetables and a decreased consumption of snacks.

CONCLUSION

Adolescents preferred unhealthy food items, but they also reported more frequent consumption of healthy than unhealthy food items. A higher threshold for the bitter taste, that is, being less sensitive to bitter taste, was associated with higher liking and familiarity of vegetables.

Associations between depressive symptom profiles and immunometabolic characteristics in individuals with depression and their siblings

OBJECTIVES

The present study examined associations between immunometabolic characteristics (IMCs) and depressive symptom profiles (DSPs) in probands with lifetime diagnoses of depression and/or anxiety disorders and their siblings.

METHODS

Data were from the Netherlands Study of Depression and Anxiety, comprising 256 probands with lifetime diagnoses of depression and/or anxiety and their 380 siblings. Measured IMCs included blood pressure, waist circumference, and levels of glucose, triglycerides, HDL cholesterol, CRP, TNF-α and IL-6. DSPs included mood, cognitive, somatic and atypical-like profiles. We cross-sectionally examined whether DSPs were associated with IMCs within probands and within siblings, and whether DSPs were associated with IMCs between probands and siblings.

RESULTS

Within probands and within siblings, higher BMI and waist circumference were associated with higher somatic and atypical-like profiles. Other IMCs (IL-6, glucose and HDL cholesterol) were significantly related to DSPs either within probands or within siblings. DSPs and IMCs were not associated between probands and siblings.

CONCLUSIONS

The results suggest that there is a familial component for each trait, but no common familial factors for the association between DSPs and IMCs. Alternative mechanisms, such as direct causal effects or non-shared environmental risk factors, may better fit these results.

Genetic and Environmental Influences of Dietary Indices in a UK Female Twin Cohort

A healthy diet is associated with the improvement or maintenance of health parameters, and several indices have been proposed to assess diet quality comprehensively. Twin studies have found that some specific foods, nutrients and food patterns have a heritable component; however, the heritability of overall dietary intake has not yet been estimated. Here, we compute heritability estimates of the nine most common dietary indices utilized in nutritional epidemiology. We analyzed 2590 female twins from TwinsUK (653 monozygotic [MZ] and 642 dizygotic [DZ] pairs) who completed a 131-item food frequency questionnaire (FFQ). Heritability estimates were computed using structural equation models (SEM) adjusting for body mass index (BMI), smoking status, Index of Multiple Deprivation (IMD), physical activity, menopausal status, energy and alcohol intake. The AE model was the best-fitting model for most of the analyzed dietary scores (seven out of nine), with heritability estimates ranging from 10.1% (95% CI [.02, .18]) for the Dietary Reference Values (DRV) to 42.7% (95% CI [.36, .49]) for the Alternative Healthy Eating Index (A-HEI). The ACE model was the best-fitting model for the Healthy Diet Indicator (HDI) and Healthy Eating Index 2010 (HEI-2010) with heritability estimates of 5.4% (95% CI [-.17, .28]) and 25.4% (95% CI [.05, .46]), respectively. Here, we find that all analyzed dietary indices have a heritable component, suggesting that there is a genetic predisposition regulating what you eat. Future studies should explore genes underlying dietary indices to further understand the genetic disposition toward diet-related health parameters.

Preference and detrimental effects of high fat, sugar, and salt diet in wild-caught Drosophila simulans are reversed by flight exercise

High saturated fat, sugar, and salt contents are a staple of a Western diet (WD), contributing to obesity, metabolic syndrome, and a plethora of other health risks. However, the combinatorial effects of these ingredients have not been fully evaluated. Here, using the wild-caught Drosophila simulans, we show that a diet enriched with saturated fat, sugar, and salt is more detrimental than each ingredient separately, resulting in a significantly decreased lifespan, locomotor activity, sleep, reproductive function, and mitochondrial function. These detrimental effects were more pronounced in female than in male flies. Adding regular flight exercise to flies on the WD markedly negated the adverse effects of a WD. At the molecular level, the WD significantly increased levels of triglycerides and caused mitochondrial dysfunction, while exercise counterbalanced these effects. Interestingly, fruit flies developed a preference for the WD after pre-exposure, which was averted by flight exercise. The results demonstrate that regular aerobic exercise can mitigate adverse dietary effects on fly mitochondrial function, physiology, and feeding behavior. Our data establish Drosophila simulans as a novel model of diet-exercise interaction that bears a strong similarity to the pathophysiology of obesity and eating disorders in humans.

Psychometric examination of the Japanese translation of the Satter eating competence Inventory-2.0™ for parents of fifth and sixth grade students

AIM

To verify the reliability and validity of a Japanese translation of the Satter eating competence Inventory-2.0™ (ecSI-2.0™) for parents of fifth and sixth grade elementary school students.

METHODS

Participants were parents who prepared meals for their children aged 10-12 years. A preliminary study was conducted with 11 parents using semi-structured interviews and questionnaires, followed by a main study of 2,825 parents. Internal consistency and test-retest methods were used to verify reliability. Face and content validity were confirmed in the preliminary study, and feasibility was examined by the valid response rate and response time. Construct validity was verified using factor validity and known population validity.

RESULTS

Of the 2,825 persons surveyed, 626 returned valid responses, and among the 60 persons who received the re-survey, 48 returned valid responses. The average score of the Japanese translation of the ecSI-2.0™ was 33.1 (SD ± 7.8) points. Cronbach's alpha coefficient for the whole scale was .87 and ranged from .67-.79 for the four subscales. The test-retest method confirmed the scale's stability. Factor analysis confirmed that reproducibility of the four factors was similar to the original version. In the examination of known population validity, the same correlation as the original edition was confirmed.

CONCLUSIONS

The Japanese translation of the ecSI-2.0™ may be reliable and valid for understanding eating competence related to behavior of parents of school-age children.

Causes of Variation in Food Preference in the Netherlands

Our current society is characterized by an increased availability of industrially processed foods with high salt, fat and sugar content. How is it that some people prefer these unhealthy foods while others prefer more healthy foods? It is suggested that both genetic and environmental factors play a role. The aim of this study was to (1) identify food preference clusters in the largest twin-family study into food preference to date and (2) determine the relative contribution of genetic and environmental factors to individual differences in food preference in the Netherlands. Principal component analysis was performed to identify the preference clusters by using data on food liking/disliking from 16,541 adult multiples and their family members. To estimate the heritability of food preference, the data of 7833 twins were used in structural equation models. We identified seven food preference clusters (Meat, Fish, Fruits, Vegetables, Savory snacks, Sweet snacks and Spices) and one cluster with Drinks. Broad-sense heritability (additive [A] + dominant [D] genetic factors) for these clusters varied between .36 and .60. Dominant genetic effects were found for the clusters Fruit, Fish (males only) and Spices. Quantitative sex differences were found for Meat, Fish and Savory snacks and Drinks. To conclude, our study convincingly showed that genetic factors play a significant role in food preference. A next important step is to identify these genes because genetic vulnerability for food preference is expected to be linked to actual food consumption and different diet-related disorders.

Preadolescents' healthy eating behavior: peeping through the social norms approach

BACKGROUND

The rising childhood obesity rate is a major public health challenge. The objective of this study is to examine key underlying mechanisms for peer-related social influence on preadolescents' healthy eating behavior by including factors closely linked with the quality of preadolescents' relationship with peers.

METHODS

A cross-sectional study was conducted in a convenience sample of 278 Lithuanian preadolescents, recruited from a public school. A questionnaire containing sociodemographic questions, questions about food intake, peer-related social norms of healthy eating, social self-efficacy, vegetable preference, need for peer approval and feeling of belonging were applied. Data was analyzed using structural equation modeling.

RESULTS

The results of the SEM showed that social self-efficacy predicts feeling of belonging to the peer group and need for peer approval. Feeling of belonging and need for peer approval predict actual intake of vegetables via injunctive norms of healthy eating. However, neither feeling of belonging nor need for peer approval predicted descriptive norms of healthy eating. Contrary to our expectations, descriptive norms were found to be unrelated with actual intake of vegetables, though vegetable preference predicted actual intake of vegetables. Vegetable preference was not predicted by injunctive or descriptive peers' social norms of healthy eating.

CONCLUSIONS

The findings of this study offer insight for informing parents, teachers and for social norms marketing interventions by stressing the importance of social relations when the aim is to encourage healthy eating among preadolescents.

What Should I Eat and Why? The Environmental, Genetic, and Behavioral Determinants of Food Choice: Summary from a Pennington Scientific Symposium

This review details the proceedings of a Pennington Biomedical scientific symposium titled, "What Should I Eat and Why? The Environmental, Genetic, and Behavioral Determinants of Food Choice." The symposium was designed to review the literature about energy homeostasis, particularly related to food choice and feeding behaviors, from psychology to physiology. This review discusses the intrinsic determinants of food choice, including biological mechanisms (genetics), peripheral and central signals, brain correlates, and the potential role of the microbiome. This review also address the extrinsic determinants (environment) of food choice within our physical and social environments. Finally, this review reports the current treatment practices for the clinical management of eating-induced overweight and obesity. An improved understanding of these determinants will inform best practices for the clinical treatment and prevention of obesity. Strategies paired with systemic shifts in our public health policies and changes in our "obesogenic" environment will be most effective at attenuating the obesity epidemic.

Impact of Taste on Food Choices in Adolescence-Systematic Review and Meta-Analysis

Studies of adults report that perceived taste affects food choices and intake, which in turn may have an impact on health. However, corresponding evidence on adolescents is limited.  Our aim was to summarize current evidence of the impact of taste perception on food choice preferences or dietary intakes among adolescents (mean age 10-19.9 years). Systematic searches identified 13 papers, 12 cross-sectional and one cohort study published between 1 January 2000 to 20 February 2020 assessing the impact of taste (using phenotypic and/or genotypic markers) on food choices in adolescents without any disease conditions. Qualitative assessment in the current review indicated that individuals sensitive to bitter tastes often have a lower preference of bitter-tasting food and higher preference for sweet-tasting food. A meta-analysis of three studies on bitter-taste sensitivity revealed no difference in preference for bitter-tasting vegetables between bitter tasters and non-tasters (standardized mean difference (SMD) = 0.04; 95% CI: -0.18, 0.26; p = 0.72). Overall, a limited number of studies were available for review. As a result, we report no clear relationship between taste perception and food choices or intake in adolescents. More studies are needed to evaluate the link between adolescents' taste perceptions and dietary intake.

A review of the ketogenic diet for endurance athletes: performance enhancer or placebo effect?

BACKGROUND

The ketogenic diet has become popular among endurance athletes as a performance enhancer. This paper systematically reviews the evidence regarding the effect of the endurance athlete's ketogenic diet (EAKD) on maximal oxygen consumption (VO₂ max) and secondary performance outcomes.

METHODS

PubMed and Web of Science searches were conducted through November 2019. Inclusion criteria were documentation of EAKD (< 50 g daily carbohydrate consumed by endurance athletes), ketosis achieved (measured via serum biomarker), VO₂ max and/or secondary outcomes, English language, and peer reviewed-publication status. Articles were excluded if they were not a primary source or hypotheses were not tested with endurance athletes (i.e., individuals that compete at submaximal intensity for extended time periods). Study design, diet composition, adherence assessment, serum biomarkers, training protocols, and VO₂ max/secondary outcomes were extracted and summarized.

RESULTS

Searches identified seven articles reporting on VO₂ max and/or secondary outcomes; these comprised six intervention trials and one case study. VO₂ max outcomes (n = 5 trials, n = 1 case study) were mixed. Two of five trials reported significant increases in VO₂ max across all diets; while three trials and one case study reported no significant VO₂ max findings. Secondary outcomes (n = 5 trials, n = 1 case study) were Time to Exhaustion (TTE; n = 3 articles), Race Time (n = 3 articles), Rating of Perceived Exertion (RPE; n = 3 articles), and Peak Power (n = 2 articles). Of these, significant findings for EAKD athletes included decreased TTE (n = 1 article), higher RPE (n = 1 article), and increased Peak Power (n = 1 article).

CONCLUSION

Limited and heterogeneous findings prohibit definitive conclusions regarding efficacy of the EAKD for performance benefit. When compared to a high carbohydrate diet, there are mixed findings for the effect of EAKD consumption on VO₂ max and other performance outcomes. More randomized trials are needed to better understand the potentially nuanced effects of EAKD consumption on endurance performance. Researchers may also consider exploring the impact of genetics, recovery, sport type, and sex in moderating the influence of EAKD consumption on performance outcomes.

Like me, like you - relative importance of peers and siblings on children's fast food consumption and screen time but not sports club participation depends on age

Background

Lifestyle interventions to prevent paediatric obesity often target family and peer settings; their success is likely to depend on the influence that peers and families exert on children’s lifestyle behaviors at different developmental stages.

Objective

First, to determine whether children’s lifestyle behavior more closely resembles their peers’ or siblings’ behaviors. Secondly, to investigate longitudinally whether children’s behavioral change is predicted by that of their peers or their siblings as they grow older.

Methods

The European prospective IDEFICS/I.Family cohort (baseline survey: 2007/2008, first follow-up: 2009/2010, and second follow-up: 2013/2014) aims at investigating risk factors for overweight and related behaviors during childhood and adolescence. The present investigation includes 2694 observations of children and their siblings aged 2 to 18 years. Peers were defined as same-sex, same-age children in the same community and identified from the full cohort. The longitudinal analysis (mean follow-up time: 3.7 years) includes 525 sibling pairs. Children’s lifestyle behaviors including fast food consumption (frequency/week), screen time (hours/week) and sports club participation (hours/week) were assessed by questionnaire. Data were analyzed using multilevel linear models.

Results

Children’s lifestyle behavior was associated with the respective behavior of their peers and sibling for all 3 behaviors. For fast food consumption, the peer resemblance was more than 6-fold higher than the sibling resemblance and the peer resemblance surpassed the sibling resemblance by the age of 9–10 years. The similarities with peers for fast food consumption and screen time steadily increased, while the similarities with siblings steadily decreased with increasing age of the children (P_interaction < 0.001). In contrast, the relative importance of peers and siblings on sports club duration did not vary by the age of the children. Longitudinal results showed that children’s changes in fast food consumption were more strongly associated with those in their peer group than their sibling, in particular if the age gap between siblings was large.

Conclusion

In conclusion, our results support the implementation of multi-setting interventions for improving lifestyle behaviors in children. Our findings might also guide future intervention studies in the choice of timing and setting in which interventions are likely to be most effective. From the ages of 9–10 years onwards, family- or home-based interventions targeting children’s fast food intake and screen time behavior may become less effective than school- or community-based interventions aimed at peer groups.

Is Adolescents' Food Intake Associated with Exposure to the Food Intake of Their Mothers and Best Friends?

Both mothers’ and best friends’ food intake are associated with adolescents’ food intake, but they are rarely investigated simultaneously. In this study, we tested the associations of mothers’ and best friends’ food intake with adolescents’ intake of unhealthy and healthy food, obtained from home and from outside the home, and the moderating role of adolescents’ exposure to their food intake. Participants included 667 adolescents (53% female, M_age = 12.9) and 396 of their mothers. Within this adolescent sample, 378 best friend dyads were identified. All participants completed food frequency questionnaires. Mothers separately reported on their food intake in the presence and absence of their child, and adolescents indicated how often they ate and drank together with their best friend during school breaks. Mothers’, but not best friends’, food intake was positively related to adolescents’ intake of unhealthy and healthy food obtained from home and healthy food obtained from outside the home. Exposure to mothers’ healthy food intake magnified mother-child similarities in healthy food intake. Exposure to best friends’ intake of unhealthy food moderated adolescent-friend similarities in unhealthy food intake. Future work should assess the mechanisms that underlie these similarities, and should investigate these associations over time and in later developmental periods.

Association between Food Preferences, Eating Behaviors and Socio-Demographic Factors, Physical Activity among Children and Adolescents: A Cross-Sectional Study

The prevalence of overweight and obesity is a serious health issue among children and adolescents worldwide. This study aimed to investigate factors influencing weight status-associated food preferences and eating behaviors. A cross-sectional study was conducted to collect data from 2578 pairs of Chinese children and parents in five cities from December 2018 to March 2019. There was an increase in consumptions of processed seafood, nuts and dried fruit/vegetables, and fruit/vegetable juice, but a reduction of consuming puffed and processed meat products, sugar/artificially sweetened beverages and milk tea, and picky eating. These food preferences differentiate between sexes. Picky eating behavior was greatly presented in children of lower educated mothers or heavy-smoking fathers. Children of the lower educated fathers consumed less processed seafood and dairy products, and those of the heavy-smoking fathers consumed more puffed products, but less fruit/vegetable juice, and had greater snack preference. The father’s body mass index(BMI)status was also positively associated with unhealthy behaviors. Those who exercised daily longer showed better eating behaviors, and picky eating and fast-food lovers likely occurred in higher-income families. Our study provides an insight into that fathers being educated for health-conscious advice and physical activity may be the potential strategies to foster their children’s healthy eating patterns. Their efficacy needs to be further investigated.

Genome-wide association study of dietary intake in the UK biobank study and its associations with schizophrenia and other traits

Motivated by observational studies that report associations between schizophrenia and traits, such as poor diet, increased body mass index and metabolic disease, we investigated the genetic contribution to dietary intake in a sample of 335,576 individuals from the UK Biobank study. A principal component analysis applied to diet question item responses generated two components: Diet Component 1 (DC1) represented a meat-related diet and Diet Component 2 (DC2) a fish and plant-related diet. Genome-wide association analysis identified 29 independent single-nucleotide polymorphisms (SNPs) associated with DC1 and 63 SNPs with DC2. Estimated from over 35,000 3rd-degree relative pairs that are unlikely to share close family environments, heritabilities for both DC1 and DC2 were 0.16 (standard error (s.e.) = 0.05). SNP-based heritability was 0.06 (s.e. = 0.003) for DC1 and 0.08 (s.e = 0.004) for DC2. We estimated significant genetic correlations between both DCs and schizophrenia, and several other traits. Mendelian randomisation analyses indicated a negative uni-directional relationship between liability to schizophrenia and tendency towards selecting a meat-based diet (which could be direct or via unidentified correlated variables), but a bi-directional relationship between liability to schizophrenia and tendency towards selecting a fish and plant-based diet consistent with genetic pleiotropy.

Genetic Background of Taste Perception, Taste Preferences, and Its Nutritional Implications: A Systematic Review

Background: The rise in nutrition-related morbidity and mortality requires public health intervention programs targeting nutritional behavior. In addition to socio-economical, socio-cultural, psychological determinants, taste is one of the main factors that influence food choices. Differences in taste perception and sensitivity may be explained by genetic variations, therefore the knowledge of the extent to which genetic factors influence the development of individual taste preferences and eating patterns is important for public policy actions addressing nutritional behaviors. Our aim was to review genetic polymorphisms accounting for variability in taste and food preferences to contribute to an improved understanding of development of taste and food preferences.

Methods: The electronic databases PubMed, Scopus, and Web of Science were searched using MeSH in PubMed and free text terms for articles published between January 1, 2000 and April 13, 2018. The search strategy was conducted following the PRISMA statement. The quality of the included studies was assessed by the validated Q-Genie tool.

Results: Following the PRISMA flowchart, finally 103 articles were included in the review. Among the reviewed studies, 43 were rated to have good quality, 47 were rated to have moderate quality, and 13 were rated to have low quality. The majority of the studies assessed the association of genetic variants with the bitter taste modality, followed by articles analyzing the impact of polymorphisms on sweet and fat preferences. The number of studies investigating the association between umami, salty, and sour taste qualities and genetic polymorphisms was limited.

Conclusions: Our findings suggest that a significant association exists between TAS2R38 variants (rs713598, rs1726866, rs10246939) and bitter and sweet taste preference. Other confirmed results are related to rs1761667 (CD36) and fat taste responsiveness. Otherwise further research is essential to confirm results of studies related to genetic variants and individual taste sensitivity. This knowledge may enhance our understanding of the development of individual taste and related food preferences and food choices that will aid the development of tailored public health strategy to reduce nutrition-related disease and morbidity.

Associations Among Taste Perception, Food Neophobia and Preferences in Type 1 Diabetes Children and Adolescents: A Cross-Sectional Study

Type 1 diabetes (T1D) is one of the most common systemic diseases in childhood which predisposes the patient to serious short-term and long-term complications, affecting all body systems. Taste and olfactory impairments were first described a long time ago in adult patients affected by diabetes (both type 1 and type 2 diabetes). However, studies evaluating taste perception, behavioral attitudes (e.g., food neophobia), and preferences toward foods in children and adolescents affected by T1D are globally lacking. Therefore, the purpose of this study was to assess taste sensitivity, food neophobia, and preferences among children and adolescents affected by T1D and healthy controls in a cross-sectional study. T1D patients presented a significantly lower ability in general to correctly identify taste qualities, especially bitter and sour tastes. Moreover, they were characterized by fewer fungiform papillae compared to controls, as well as a lower responsiveness to the bitter compound 6-n-propylthiouracil (PROP). There were no significant differences in food neophobia scores between the two groups, but differences were observed in the mean hedonic ratings for some product categories investigated. Diabetic patients showed a greater liking for certain type of foods generally characterized by sourness and bitterness, an observation probably linked to their impaired ability to perceive taste stimuli, e.g., sourness and bitterness. These results may help to enhance the understanding of these relationships in populations with elevated diet-related health risks.

The Influence of Taste Liking on the Consumption of Nutrient Rich and Nutrient Poor Foods

Repeated consumption of high-energy nutrient poor foods can lead to undesirable health outcomes such as obesity. Taste plays an important role in food choice, and a better understanding of the links between the taste of foods, individual taste preferences, food choices, and intakes will aid in our understanding of why some people might select and consume unhealthy foods. The present review focuses on three main questions: (1) do nutrient poor and nutrient rich foods significantly differ in taste profile? (2) are humans predisposed toward developing a liking or preference for certain taste profiles? (3) how are individual variations in liking of the basic taste qualities related to long term food intake and adverse health outcomes such as obesity? Results indicated that nutrient poor foods were likely to be sweet, salty and fatty mouthfeel, while the taste profiles of nutrient rich foods were diverse. Although humans are born with a universal liking for sweet and aversion for bitter taste, large individual differences exist in liking of all the basic taste qualities. These individual differences partly explain differences in short term intakes of foods varying in taste profiles. However they fail to sufficiently explain long term food choices and negative health outcomes such as obesity. Future studies should focus on how the full sensory profile of food which includes taste, smell and texture interacts with individual characteristics (e.g., taste or health motivations, taste preferences) to affect consumption of nutrient rich and nutrient poor foods.

Food Parenting Practices That Influence Early Adolescents' Food Choices During Independent Eating Occasions

OBJECTIVE

To identify practices that parents use to influence early adolescents' food choices during independent eating occasions (iEOs) from parent and child perspectives.

DESIGN

In-depth interviews.

PARTICIPANTS

Low-income parents (n = 49) and early adolescent children (aged 10-13 years; n = 44) from 10 US states and the District of Columbia.

PHENOMENON OF INTEREST

Parent and child perspectives on parenting practices that influence food choices during iEOs.

ANALYSIS

Audio-recorded interviews transcribed verbatim, NVivo coding, and directed content analysis.

RESULTS

Parents reported setting rules and expectations and managing availability or accessibility as the most common practices used to influence iEOs. Other practices included teaching, pressuring to eat, monitoring, and modeling. Children reported that their parents had rules about what they could or could not eat during iEOs and that they used specific strategies (eg, call or text) to monitor their iEOs.

CONCLUSIONS AND IMPLICATIONS

Additional studies are needed to confirm findings from this exploratory study. Future cross-sectional and longitudinal studies could determine whether and to what extent food parenting practices identified in the current study are associated with healthy dietary intake during iEOs, as well as potential racial and ethnic differences.

A Brief Review of Genetic Approaches to the Study of Food Preferences: Current Knowledge and Future Directions

Genetic variation plays a crucial role in individual differences in food preferences which ultimately influence food selection and health. Our current understanding of this pathway has been informed through twin studies (to assess the heritability of food preferences), candidate gene studies, and genome-wide association studies (GWAS). However, most of this literature is mainly focused on genes previously identified as having taste or smell functions. New data suggests that genes not associated with taste or smell perception may be involved in food preferences and contribute to health outcomes. This review highlights these emerging findings and suggests a polygenic risk assessment approach to explore new relationships between food preferences and health risks.

Sleep duration and quality are associated with eating behavior in low-income toddlers

OBJECTIVE

The present study examined whether different sleep health parameters (duration, timing, and quality) are associated with obesity-related eating behaviors including emotional overeating, food responsiveness, enjoyment of food, satiety responsiveness, and eating in the absence of hunger (EAH), during toddlerhood.

DESIGN

Among 134 low-income 33-month-old children, parents reported on child sleep parameters, including sleep quality (Children's Sleep Wake Scale; CSWS) and usual bedtimes and wake times on weekdays and weekends (weeknight sleep duration, weekday-to-weekend bedtime delay). Child eating behaviors were assessed using both observed and parent-report measures. Child Emotional Overeating, Food Responsiveness, Enjoyment of Food, and Satiety Responsiveness were measured by parent report using the Child Eating Behavior Questionnaire-Toddler. Observed child EAH was evaluated by measuring kilocalories of palatable foods consumed following a meal. Multivariable linear regression was used to examine the associations between sleep parameters and eating behaviors.

RESULTS

Poorer child sleep quality was associated with greater Emotional Overeating (standardized β = -0.20 (SE 0.09), p < .05) and greater Food Responsiveness (β = -0.18 (SE 0.09), p < .05). Shorter child nighttime sleep duration was associated with greater EAH kcal consumed (standardized β = -0.22 (SE 0.09), p < .05). Child bedtime delay was not associated with any of the eating behaviors, and no child sleep variables were associated with either Enjoyment of Food or Satiety Responsiveness.

CONCLUSIONS

Shorter nocturnal sleep duration and poorer sleep quality during toddlerhood were associated with some, but not all, of the obesity-related eating behaviors. Poor sleep health may promote childhood obesity risk through different eating behavior pathways. As children growing up in poverty may experience greater sleep decrements, sleep duration and sleep quality may be important targets for intervention among low-income families with young children.