An obesity-associated FTO gene variant and increased energy intake in children

Exploring the interplay of genetic variants and environmental factors in childhood obesity: A systematic review and meta-analysis

Dynamic interactions between genetic predispositions and environmental exposures significantly shape the escalating prevalence of childhood obesity. This systematic review synthesizes observational and clinical trial evidence on the gene-environment interplays influencing childhood obesity, highlighting the role of genetic variants and environmental moderators such as dietary habits, physical activity, sleep durations, parental behaviors, socioeconomic status, ethnicity, gender, as well as lifestyle interventions. We conducted an exhaustive search across 5 databases (Medline, PubMed, EMBASE, Web of Science, and Cochrane Library), adhering to PRISMA guidelines. We ultimately included 147 studies that investigated these interplays in diverse populations. Specifically, 83 studies focused on gene-diet interplays, 23 on gene-physical activity, 5 on sedentary behavior, 3 on screen time, 7 on sleep duration, 10 on parental behavior, 4 on socioeconomic status, 16 on gender, 8 on age, 7 on ethnicity, and 13 on the effects of lifestyle interventions. Notably, we meta-analyzed energy expenditure and macronutrient consumption, including carbohydrates, proteins, and fats, as well as the proportion of energy supplied by each nutrient between carriers and noncarriers of the FTO effect allele, revealing that carriers consumed a higher proportion of fat calories, with no other significant differences noted. This review demonstrates that genetic risk variants, particularly in FTO (e.g., rs9939609) and MC4R (e.g., rs17782313), amplify the adverse effects of obesogenic behaviors, offering insights into the intricate pathophysiology of childhood obesity and suggesting the potential for personalized interventions based on genetic profiles.

Higher risk of metabolic syndrome in children and adolescents and polymorphisms in the fat mass and obesity-associated gene: a systematic review and meta-analysis

BACKGROUND

The relationship between polymorphisms in fat mass and obesity-associated gene (FTO) and the components of metabolic syndrome (MetS) has been explored among children and adolescents, but the results are inconsistent and inconclusive.

METHODS

Electronic databases including Medline, Scopus, Embase, Web of Science, CNKI, and Google Scholar were searched for eligible studies, and data were extracted from each study. Standardized mean differences were calculated to examine the differences in the components of MetS between FTO genotypes.

RESULTS

Forty-six studies (45,100 subjects), seven studies (4216 subjects), and six studies (2699 subjects) were included in the meta-analyses for FTOrs9939609, FTOrs1421085, and FTOrs17817449 polymorphisms, respectively. A-allele carriers of FTOrs9939609 polymorphism had higher levels of waist circumference (WC), systolic blood pressure, and fasting blood glucose, but lower levels of high-density lipoprotein cholesterol (HDL-C) than TT homozygotes (p < 0.05 for all). C-allele carriers of FTOrs1421085 polymorphism had higher levels of WC and lower levels of HDL-C than TT homozygotes (p < 0.05 for both). No significant associations between FTOrs17817449 polymorphism and the components of MetS were detected.

CONCLUSION

The meta-analysis demonstrates that A allele of FTOrs9939609 and C allele of FTOrs1421085 polymorphisms confer a higher risk of MetS among children and adolescents.

IMPACT STATEMENT

Genetic polymorphisms are closely related to metabolic syndrome in children and adolescents. The rs9939609 polymorphism in fat mass and obesity-associated gene is apparently associated with a higher risk of metabolic syndrome among children and adolescents. The findings of this study can provide reference for gene diagnosis and gene therapy of metabolic syndrome in children and adolescents.

Genetic associations with consumption of palatable foods in the absence of hunger in response to food cues in children

OBJECTIVE

The objective of this study is to evaluate obesity-related genetic factors in relation to excess consumption and assess if food cues modify associations.

METHODS

Children (9-12 years) completed a randomized crossover experiment. During two visits, children ate a preload and then snacks ad libitum while watching television, embedded with food or non-food advertisements to assess eating in the absence of hunger (EAH). Primary exposures were obesity-associated genotypes, FTO rs9939609 and MC4R rs571312, and a paediatric-specific polygenic risk score (PRS). Outcomes included consumption of all snacks (total EAH) and gummy candy only (gummy candy EAH). Linear mixed-effects models tested whether genetic exposures related to EAH outcomes. We tested for effect modification by food cues using multiplicative interaction terms.

RESULTS

Among 177 children, each FTO risk allele was associated with a 30% increase in gummy candy EAH (p = 0.025) in adjusted models. Food cue exposure exacerbated associations between the FTO variant with gummy candy EAH (p = 0.046). No statistically significant associations were found between MC4R and EAH.

CONCLUSION

The results suggest children with the FTO rs9939609 risk allele may be predisposed to excess consumption of candy and that this association may be exacerbated by food cues.

The Secret Life of N1-methyladenosine: A Review on its Regulatory Functions

N1-methyladenosine (m1A) is a conserved modification on house-keeping RNAs, including tRNAs and rRNAs. With recent advancement on m1A detection and mapping, m1A is revealed to have a secret life with regulatory functions. This includes the regulation of its canonical substrate tRNAs, and expands into new territories such as tRNA fragments, mRNAs and repeat RNAs. The dynamic regulation of m1A has been shown in different biological contexts, including stress response, diet, T cell activation and aging. Interestingly, m1A can also be installed by non-enzymatic mechanisms. However, technical challenges remain in m1A site mapping; as a result, controversies have been observed across different labs or different methods. In this review we will summarize the recent development of m1A detection, its dynamic regulation, and its biological functions on diverse RNA substrates.

An obesogenic FTO allele causes accelerated development, growth and insulin resistance in human skeletal muscle cells

Human GWAS have shown that obesogenic FTO polymorphisms correlate with lean mass, but the mechanisms have remained unclear. It is counterintuitive because lean mass is inversely correlated with obesity and metabolic diseases. Here, we use CRISPR to knock-in FTOrs9939609-A into hESC-derived tissue models, to elucidate potentially hidden roles of FTO during development. We find that among human tissues, FTOrs9939609-A most robustly affect human muscle progenitors' proliferation, differentiation, senescence, thereby accelerating muscle developmental and metabolic aging. An edited FTOrs9939609-A allele over-stimulates insulin/IGF signaling via increased muscle-specific enhancer H3K27ac, FTO expression and m6A demethylation of H19 lncRNA and IGF2 mRNA, with excessive insulin/IGF signaling leading to insulin resistance upon replicative aging or exposure to high fat diet. This FTO-m6A-H19/IGF2 circuit may explain paradoxical GWAS findings linking FTOrs9939609-A to both leanness and obesity. Our results provide a proof-of-principle that CRISPR-hESC-tissue platforms can be harnessed to resolve puzzles in human metabolism.

A Whole Plant-Foods Diet in the Prevention and Treatment of Overweight and Obesity: From Empirical Evidence to Potential Mechanisms

Excess body adiposity, referred to as overweight and obesity, represents a major health concern given that it increases the risk of various diseases, including cardiovascular diseases, type 2 diabetes, and cancer. Body weight reduction can be achieved via a wide variety of dietary strategies as long as an energy deficit is achieved. However, the effect of such diets on disease risk and mortality will depend on the foods included. Increasing evidence shows that consumption of whole plant foods (e.g., fruits, vegetables, whole grains, nuts, seeds, legumes) in place of animal foods (e.g., meat, poultry, dairy, fish, eggs, and seafood and their derivatives) and non-whole plant foods (e.g., refined grains, French fries, sugar-sweetened beverages) is associated with improvements in cardiometabolic risk factors and lower risk of chronic diseases and mortality. This review focuses on the effect of a whole plant-foods diet on overweight and obesity from observational to clinical studies and discusses the potential mechanisms involved. According to existing evidence, a whole plant foods diet seems to be more advantageous than other dietary approaches for the prevention and treatment of excess adiposity given that it is composed of the foods that lead to the best health outcomes.

FTO in health and disease

Fat mass and obesity-associated (FTO) protein, a key enzyme integral to the dynamic regulation of epitranscriptomic modifications in RNAs, significantly influences crucial RNA lifecycle processes, including splicing, export, decay, and translation. The role of FTO in altering the epitranscriptome manifests across a spectrum of physiological and pathological conditions. This review aims to consolidate current understanding regarding the implications of FTO in health and disease, with a special emphasis on its involvement in obesity and non-communicable diseases associated with obesity, such as diabetes, cardiovascular disease, and cancer. It also summarizes the established molecules with FTO-inhibiting activity. Given the extensive impact of FTO on both physiology and pathophysiology, this overview provides illustrative insights into its roles, rather than an exhaustive account. A proper understanding of FTO function in human diseases could lead to new treatment approaches, potentially unlocking novel avenues for addressing both metabolic disorders and malignancies. The evolving insights into FTO's regulatory mechanisms hold great promise for future advancements in disease treatment and prevention.

Association of FTO variants rs9939609 and rs1421085 with elevated sugar and fat consumption in adult obesity

This cross-sectional study explores the impact of FTO gene single nucleotide polymorphisms (SNPs) rs9939609 and rs1421085 on dietary habits contributing to obesity risk in Thai adults. The study enrolled 384 participants from Bangkok, categorized as non-obese (BMI < 25 kg/m2) or obese (BMI ≥ 25 kg/m2) based on WHO Asia Pacific Guidelines. Genotyping for FTO variants was performed using DNA from blood samples. While both SNPs adhered to Hardy-Weinberg equilibrium, the association between risk alleles and anthropometric measurements was not statistically significant. However, risk allele carriers showed significantly higher intakes of sugar and saturated fat compared to homozygous dominant individuals. In the obese group, the odds ratio for high-sugar intake was 2.22 (95% CI 1.13-4.37, p = 0.021) for rs9939609 risk allele carriers. For high-saturated fat intake, the odds ratio was 1.86 (95% CI 1.02-3.40, p = 0.041). Similar associations were observed for rs1421085. Risk allele carriers also exhibited significantly higher leptin levels (p < 0.043) and a positive correlation with myeloperoxidase levels (p < 0.038). These findings highlight the complex relationship between FTO risk alleles, increased consumption of sugar and saturated fat, and obesity-related parameters. The insights emphasize the importance of considering both genetic and dietary factors in obesity prevention strategies.

Genetic associations with neural reward responsivity to food cues in children

Objective

To test associations of candidate obesity-related single nucleotide polymorphisms (SNPs) and obesity polygenic risk scores (PRS) with neural reward reactivity to food cues.

Methods

After consuming a pre-load meal, 9-12-year-old children completed a functional magnetic resonance imaging (fMRI) paradigm with exposure to food and non-food commercials. Genetic exposures included FTO rs9939609, MC4R rs571312, and a pediatric-specific obesity PRS. A targeted region-of-interest (ROI) analysis for 7 bilateral reward regions and a whole-brain analysis were conducted. Independent associations between each genetic factor and reward responsivity to food cues in each ROI were evaluated using linear models.

Results

Analyses included 151 children (M = 10.9 years). Each FTO rs9939609 obesity risk allele was related to a higher food-cue-related response in the right lateral hypothalamus after controlling for covariates including the current BMI Z-score (p < 0.01), however, the association did not remain significant after applying the multiple testing correction. MC4R rs571312 and the PRS were not related to heightened food-cue-related reward responsivity in any examined regions. The whole-brain analysis did not identify additional regions of food-cue-related response related to the examined genetic factors.

Conclusion

Children genetically at risk for obesity, as indicated by the FTO genotype, may be predisposed to higher food-cue-related reward responsivity in the lateral hypothalamus in the sated state, which, in turn, could contribute to overconsumption.

Clinical trial registration

https://clinicaltrials.gov/study/NCT03766191, identifier NCT03766191.

Genes Involved in Susceptibility to Obesity and Emotional Eating Behavior in a Romanian Population

Obesity, a significant public health concern with high prevalence in both adults and children, is a complex disorder arising from the interaction of multiple genes and environmental factors. Advances in genome-wide association studies (GWAS) and sequencing technologies have identified numerous polygenic causes of obesity, particularly genes involved in hunger, satiety signals, adipocyte differentiation, and energy expenditure. This study investigates the relationship between six obesity-related genes (CLOCK, FTO, GHRL, LEP, LEPR, MC4R) and their impact on BMI, WC, HC, WHR, and emotional eating behavior in 220 Romanian adults. Emotional eating was assessed using the validated Emotional Eating Questionnaire (EEQ). Our analysis revealed significant variability in obesity-related phenotypes and emotional eating behaviors across different genotypes. Specifically, CLOCK/CC, FTO/AA, and LEP/AA genotypes were strongly associated with higher obesity metrics and emotional eating scores, while GHRL/TT and MC4R/CC were linked to increased BMI and WHR. The interplay between genetic predisposition and emotional eating behavior significantly influenced BMI and WHR, indicating a complex relationship between genetic and behavioral factors. This study, the first of its kind in Romania, provides a foundation for targeted interventions to prevent and reduce obesity and suggests potential strategies for gene expression modulation to mitigate the effects of emotional eating. Adopting a 'One Health' approach by creating an evidence base derived from both human and animal studies is crucial for understanding how to control obesity.

Translational potential of mouse models of human metabolic disease

Obesity causes significant morbidity and mortality globally. Research in the last three decades has delivered a step-change in our understanding of the fundamental mechanisms that regulate energy homeostasis, building on foundational discoveries in mouse models of metabolic disease. However, not all findings made in rodents have translated to humans, hampering drug discovery in this field. Here, we review how studies in mice and humans have informed our current framework for understanding energy homeostasis, discuss their challenges and limitations, and offer a perspective on how human studies may play an increasingly important role in the discovery of disease mechanisms and identification of therapeutic targets in the future.

The interaction of the FTO gene and age interferes with macronutrient and vitamin intake in women with morbid obesity

Fat mass and obesity-related (FTO) gene single nucleotide polymorphisms (SNPs) interferes with food preferences that impact macronutrient intake. Few studies have investigated the relationship of this polymorphisms with the intake of micronutrients. Moreover, studies have shown multiple micronutrient deficiencies in patients with obesity. This work evaluated the effect of the FTO rs9939609 gene polymorphism on dietary nutritional quality and food intake of macronutrients and vitamins in of women with obesity candidates for metabolic surgery. The study included 106 women (24 to 60 years old) with BMIs of 36.1 to 64.8 kg/m2. A food frequency questionnaire validated for the local population was applied to obtain information about food intake. The Index of Nutritional Quality (INQ) was used to assess the adequacy of macronutrient and vitamin intake. Energy, protein and lipid intakes were higher in carriers of the A allele compared to TT in the younger age groups but were similar in the class of subjects aged ≥45 years. The INQ for protein was higher in carriers of the A allele than in carriers of the TT allele. The INQs for protein, carbohydrate, vitamins B2, B3 and B6 decreased, whereas the INQ for vitamin C increased with advancing age. The INQ for vitamin A was lower in AA than in TT, regardless of age, whereas vitamin E was higher in younger AA than in older AA. The INQ for vitamin B9 was higher in younger women than in older women. In conclusion, the FTO gene contributed to the intake of more energy, protein and lipids and interfered with the intake of vitamins B9, A and E. With the exception of vitamin A, the effect of the genotype was attenuated with ageing.

Associations Between rs9939609 FTO Polymorphism With Nutrient and Food Intake and Adherence to Dietary Patterns in an Urban Argentinian Population

BACKGROUND

The A allele of rs9939609 polymorphism at the FTO gene has been consistently associated with higher body mass index in different populations, but conflicting results have been found regarding its contribution to food intake variability.

OBJECTIVE

This study aimed to investigate the association between this genetic variant and nutrient and food intake in an urban Argentinian population.

DESIGN

A cross-sectional, analytic investigation was performed between October 2018 and February 2020.

PARTICIPANTS/SETTINGS

Adults of both sexes residing in La Plata, Argentina, were recruited through social networks (Instagram and Facebook). Of 179 eligible adults, a total of 173 adults were included in the final analyses.

OUTCOME MEASURES

Nutrient and food group intake data were obtained by an interview-administered food frequency questionnaire. Height and weight were measured, and genotypes were obtained by real-time polymerase chain reaction.

STATISTICAL ANALYSES

The per-allele effect on nutrient and food group intake was assessed by general linear models, adjusting for age, sex, educational level, total energy intake, and body mass index. Dietary patterns were derived by principal component analysis. The association of the A allele with adherence to each dietary pattern was also evaluated by the general linear model.

RESULTS

The frequency of the risk allele was 27%. A-carriers showed a higher total fat (1.88 [0.55, 3.21] % of total energy intake), saturated fatty acids (0.82 [0.25-1.39] % of total energy intake), and monounsaturated fatty acids (0.66 [0.08, 1.24] % of total energy intake), and a lower carbohydrate (-1.99 [-3.48, -0.50] % of total energy intake) intake than TT homozygous. A-carriers also reported a higher "milk and yogurt" (1.08 [0.24, 1.91] % of total energy intake), "animal fats" (1.09 [0.14-2.03] % of total energy intake), and fat-rich ultraprocessed foods (2.10 [0.52, 3.67] % of total energy intake) intake in comparison with TT homozygous. Furthermore, A-carriers showed higher adherence to the Western dietary pattern.

CONCLUSION

The A allele contributed to nutrient and food intake variability in the studied population and was associated with the consumption of saturated fatty acids-enriched foods.

Genetics, pharmacotherapy, and dietary interventions in childhood obesity

Childhood obesity has emerged as a major global health issue, contributing to the increased prevalence of chronic conditions and adversely affecting the quality of life and future prospects of affected individuals, thereby presenting a substantial societal challenge. This complex condition, influenced by the interplay of genetic predispositions and environmental factors, is characterized by excessive energy intake due to uncontrolled appetite regulation and a Westernized diet. Managing obesity in childhood requires specific considerations compared with adulthood, given the vulnerability of the critical juvenile-adolescent period to toxicity and developmental defects. Consequently, common treatment options for adult obesity may not directly apply to younger populations. Therefore, research on childhood obesity has focused on genetic defects in regulating energy intake, alongside pharmacotherapy and dietary interventions as management approaches, with an emphasis on safety concerns. This review aims to summarize canonical knowledge and recent findings on genetic factors contributing to childhood obesity. Additionally, it assesses the efficacy and safety of existing pharmacotherapies and dietary interventions and suggests future research directions. By providing a comprehensive understanding of the complex dynamics of childhood obesity, this review aims to offer insights into more targeted and effective strategies for addressing this condition, including personalized healthcare solutions.

FTO genotype and body mass index reduction in childhood obesity interventions: A systematic review and meta-analysis

Numerous guidelines have called for personalized interventions to address childhood obesity. The role of fat mass and obesity-associated gene (FTO) in the risk of childhood obesity has been summarized. However, it remains unclear whether FTO could influence individual responses to obesity interventions, especially in children. To address this, we systematically reviewed 12,255 records across 10 databases/registers and included 13 lifestyle-based obesity interventions (3980 children with overweight/obesity) reporting changes in body mass index (BMI) Z-score, BMI, waist circumference, waist-to-hip ratio, and body fat percentage after interventions. These obesity-related outcomes were first compared between children carrying different FTO genotypes (rs9939609 or its proxy) and then synthesized by random-effect meta-analysis models. The results from single-group interventions showed no evidence of associations between FTO risk allele and changes in obesity-related outcomes after interventions (e.g., BMI Z-score: -0.01; 95% CI: -0.04, 0.01). The results from controlled trials showed that associations between the FTO risk allele and changes in obesity-related outcomes did not differ by intervention/control group. To conclude, the FTO risk allele might play a minor role in the response to obesity interventions among children. Future studies might pay more attention to the accumulation effect of multiple genes in the intervention process among children.

Factors Correlated With Ultra-Processed Food (UPF) Intake in Preschool-Aged Children and Association With Weight

OBJECTIVE

Understand the correlates of ultra-processed food (UPF) intake and examine the association of UPF on body mass index in children aged 3-5 years.

DESIGN

Secondary analysis of a prospective cohort of 3-5-year-olds/parent, followed 1-year between March 2014 and October 2016. Usual UPF intake from 2 3-day food records completed 1 year apart, a standardized nutrient database customized with child-specific foods, and a NOVA food classification system was used. Child/parent characteristics and media use were measured via parent-reported surveys. Child weight/height objectively measured.

SETTING

New Hampshire community.

PARTICIPANTS

Six hundred and sixty-seven parent-child dyads were screened, and 624 were enrolled with 90% follow-up.

MAIN OUTCOME MEASURE(S)

Primary outcome: identify correlates of UPF intake.

SECONDARY OUTCOME

determine if UPF intake is associated with body mass index change.

ANALYSIS

Adjusted β linear regression, linear regression, P <0.05.

RESULTS

Ultra-processed food accounted for 67.6% of total caloric intake. In adjusted models, children's UPF intake was positively associated with increasing child age, greater hours watching television, and more frequent parent soda/fast-food intake. Ultra-processed food intake was negatively associated with higher parent education and reported race/ethnicity other than non-Hispanic White. There was no association between UPF intake and weight.

CONCLUSIONS AND IMPLICATIONS

There are several predictors of UPF intake in young children. Family-level interventions could be implemented to encourage the intake of minimally processed foods before and during preschool years.

Potential Mechanisms of Precision Nutrition-Based Interventions for Managing Obesity

Precision nutrition (PN) considers multiple individual-level and environmental characteristics or variables to better inform dietary strategies and interventions for optimizing health, including managing obesity and metabolic disorders. Here, we review the evidence on potential mechanisms-including ones to identify individuals most likely to respond-that can be leveraged in the development of PN interventions addressing obesity. We conducted a review of the literature and included laboratory, animal, and human studies evaluating biochemical and genetic data, completed and ongoing clinical trials, and public programs in this review. Our analysis describes the potential mechanisms related to 6 domains including genetic predisposition, circadian rhythms, physical activity and sedentary behavior, metabolomics, the gut microbiome, and behavioral and socioeconomic characteristics, i.e., the factors that can be leveraged to design PN-based interventions to prevent and treat obesity-related outcomes such as weight loss or metabolic health as laid out by the NIH 2030 Strategic Plan for Nutrition Research. For example, single nucleotide polymorphisms can modify responses to certain dietary interventions, and epigenetic modulation of obesity risk via physical activity patterns and macronutrient intake have also been demonstrated. Additionally, we identified limitations including questions of equitable implementation across a limited number of clinical trials. These include the limited ability of current PN interventions to address systemic influences such as supply chains and food distribution, healthcare systems, racial or cultural inequities, and economic disparities, particularly when designing and implementing PN interventions in low- and middle-income communities. PN has the potential to help manage obesity by addressing intra- and inter-individual variation as well as context, as opposed to "one-size fits all" approaches though there is limited clinical trial evidence to date.

Unraveling Adipose Tissue Dysfunction: Molecular Mechanisms, Novel Biomarkers, and Therapeutic Targets for Liver Fat Deposition

Adipose tissue (AT), once considered a mere fat storage organ, is now recognized as a dynamic and complex entity crucial for regulating human physiology, including metabolic processes, energy balance, and immune responses. It comprises mainly two types: white adipose tissue (WAT) for energy storage and brown adipose tissue (BAT) for thermogenesis, with beige adipocytes demonstrating the plasticity of these cells. WAT, beyond lipid storage, is involved in various metabolic activities, notably lipogenesis and lipolysis, critical for maintaining energy homeostasis. It also functions as an endocrine organ, secreting adipokines that influence metabolic, inflammatory, and immune processes. However, dysfunction in WAT, especially related to obesity, leads to metabolic disturbances, including the inability to properly store excess lipids, resulting in ectopic fat deposition in organs like the liver, contributing to non-alcoholic fatty liver disease (NAFLD). This narrative review delves into the multifaceted roles of WAT, its composition, metabolic functions, and the pathophysiology of WAT dysfunction. It also explores diagnostic approaches for adipose-related disorders, emphasizing the importance of accurately assessing AT distribution and understanding the complex relationships between fat compartments and metabolic health. Furthermore, it discusses various therapeutic strategies, including innovative therapeutics like adipose-derived mesenchymal stem cells (ADMSCs)-based treatments and gene therapy, highlighting the potential of precision medicine in targeting obesity and its associated complications.

FTO variation and early frontostriatal brain development in children

OBJECTIVE

Common obesity-associated genetic variants at the fat mass and obesity-associated (FTO) locus have been associated with appetitive behaviors and altered structure and function of frontostriatal brain regions. The authors aimed to investigate the influence of FTO variation on frontostriatal appetite circuits in early life.

METHODS

Data were drawn from RESONANCE, a longitudinal study of early brain development. Growth trajectories of nucleus accumbens and frontal lobe volumes, as well as total gray matter and white matter volume, by risk allele (AA) carrier status on FTO single-nucleotide polymorphism rs9939609 were examined in 228 children (102 female, 126 male) using magnetic resonance imaging assessments obtained from infancy through middle childhood. The authors fit functional concurrent regression models with brain volume outcomes over age as functional responses, and FTO genotype, sex, BMI z score, and maternal education were included as predictors.

RESULTS

Bootstrap pointwise 95% CI for regression coefficient functions in the functional concurrent regression models showed that the AA group versus the group with no risk allele (TT) had greater nucleus accumbens volume (adjusted for total brain volume) in the interval of 750 to 2250 days (2-6 years).

CONCLUSIONS

These findings suggest that common genetic risk for obesity is associated with differences in early development of brain reward circuitry and argue for investigating dynamic relationships among genotype, brain, behavior, and weight throughout development.

The mediatory role of inflammatory markers on the relationship between the NOVA classification system and obesity phenotypes among obese and overweight adult women: a cross-sectional study

Background

Diet and inflammation both play important roles in the occurrence of obesity. We aimed to investigate the role of inflammation in the development of both metabolically healthy obese (MHO) and metabolically unhealthy obese (MUHO) individuals.

Methods

This cross-sectional study included 221 overweight and obese women aged 18-56 years. The study assessed the metabolic health phenotypes of the participants using the Karelis criterion score. Additionally, dietary intakes were evaluated using a 147-item semi-quantitative questionnaire and the NOVA classification system (comprising 37 food groups and beverages). The study also collected and analyzed the blood parameters, as well as biochemical and anthropometric indices, for all participants.

Results

Among the women included in the study, 22.9% had MHO phenotypes but 77.1% had MUHO phenotypes. A significant association between the third quartile of the NOVA classification system and the increased likelihood of having the MUHO phenotype was observed (OR = 1.40, 95% CI = 1.09-4.92, p = 0.04). Regarding the potential role of inflammatory markers, high-sensitivity C-reactive protein (hs-CRP) (p = 0.84), transforming growth factor-β (TGF-β) (p = 0.50), monocyte chemoattractant protein-1 (MCP-1) (p = 0.49), plasminogen activator inhibitor-1 (PAI-1) (p = 0.97), and homeostatic model assessment for insulin resistance (HOMA-IR) (p = 0.92) were found to be mediators.

Conclusion

We observed a significant positive association between ultra-processed food (UPF) consumption and the MUHO phenotype in overweight and obese women. This association appeared to be mediated by some inflammatory markers, such as hs-CRP, TGF-β, MCP-1, PAI-1, and HOMA-IR. Additional studies are needed to validate these findings.

FTO and MC4R polymorphisms, and selected pre-, peri- and postnatal factors as determinants of body mass index and fatness in children: a thorough analysis of the associations

BACKGROUND

Overweight and obesity among children have become significant global health concerns. Previous studies have highlighted the potential role of genetic factors, particularly polymorphisms in the FTO and MC4R genes, as well as environmental factors in the development of childhood obesity. This study aimed to investigate the relationships between genetic, socioeconomic and perinatal factors, adverse childhood events (ACEs), and lifestyle, and their impact on overweight, obesity and body composition parameters in children. Additionally, we explored potential interactions between genetic factors and ACEs.

METHODS

Four hundred fifty-six children aged 6-12 years participated in our study. Information on the socioeconomic status, perinatal factors, ACEs and lifestyle of the children was collected with a questionnaire completed by their parents/guardians. We examined the children's body weight and conducted an electrical bioimpedance analysis. Overweight and obesity were diagnosed based on the International Obesity Task Force and McCarthy criteria. We genotyped two selected polymorphisms in the FTO and MC4R genes using the TaqMan SNP allelic discrimination method.

RESULTS

Higher BMI (Body Mass Index) z scores were related to higher paternal BMI and lower maternal age at the child's birth. Higher FMI (Fat Mass Index) z scores were associated with higher paternal BMI, increased gestational weight, lower maternal education and the presence of the FTO risk allele. Higher FatM (fat mass in kg) z scores were linked to lower maternal education, lower maternal age at the child's birth, higher maternal body weight gain, paternal BMI and the presence of the FTO risk allele. Moreover, interaction effects were observed on BMI z scores between ACE and FTO AA, and on FMI z scores and FatM z scored between ACE and MC4R CC.

CONCLUSIONS

The contribution of environmental factors is more strongly related to changes in body composition than genetic ones. Additionally, the presence of the risk allele combined with unfavourable environmental factors like ACEs leads to visible interaction effects, resulting in increased BMI z scores and FMI z scores in children.

Fat mass and obesity-associated gene (FTO) rs9939609 (A/T) polymorphism and food preference in obese people with low-calorie intake and non-obese individuals with high-calorie intake

The purpose of this study was to assess the connection between FTO rs9939609 (A/T) polymorphism and food preference. The study included 77 participants, 36 of whom were obese and had a low-calorie intake, and 41 non-obese participants with a high-calorie intake. Using a food frequency questionnaire (FFQ), the researchers calculated sweet and fatty food propensity scores. Genomic DNA was extracted from a peripheral blood sample from all participants, and FTO rs9939609 (A/T) polymorphism was assessed using standard methods. The study found no significant differences between the two groups in terms of sweet food preference (15.64 ± 10.53 in obese groups vs. 14.72 ± 7.95 in the non-obese group, p = 0.711) and fatty food preference (16.81 ± 8.84 vs. 17.27 ± 8.75; p = 0.833). Additionally, the study did not find any significant correlation between FTO rs9939609 (A/T) polymorphism and sweet and fatty food preferences in the fully adjusted models (p > 0.05). Therefore, the results of this study do not support the hypothesis of different food preferences.

Studies on the fat mass and obesity-associated (FTO) gene and its impact on obesity-associated diseases

Obesity has become a major health crisis in the past ∼50 years. The fat mass and obesity-associated (FTO) gene, identified by genome-wide association studies (GWAS), was first reported to be positively associated with obesity in humans. Mice with more copies of the FTO gene were observed to be obese, while loss of the gene in mice was found to protect from obesity. Later, FTO was found to encode an m6A RNA demethylase and has a profound effect on many biological and metabolic processes. In this review, we first summarize recent studies that demonstrate the critical roles and regulatory mechanisms of FTO in obesity and metabolic disease. Second, we discuss the ongoing debates concerning the association between FTO polymorphisms and obesity. Third, since several small molecule drugs and micronutrients have been found to regulate metabolic homeostasis through controlling the expression or activity of FTO, we highlight the broad potential of targeting FTO for obesity treatment. Improving our understanding of FTO and the underlying mechanisms may provide new approaches for treating obesity and metabolic diseases.

Biobehavioral susceptibility for obesity in childhood: Behavioral, genetic and neuroimaging studies of appetite

Modern food environments are conducive to overeating and weight gain, but not everyone develops obesity. One reason for this may be that individuals differ in appetitive characteristics, or traits, that manifest early in life and go on to influence their behavioral susceptibility to gain and maintain excess weight. Classic studies showing that eating behavior in children can be measured by behavioral paradigms such as tests of caloric compensation and eating in the absence of hunger inspired the development and validation of psychometric instruments to assess appetitive characteristics in children and infants. A large body of evidence now suggests that food approach traits increase obesity risk, while food avoidant traits, such as satiety responsiveness, decrease obesity risk. Twin studies and genetic association studies have demonstrated that appetitive characteristics are heritable, consistent with a biological etiology. However, family environment factors are also influential, with mounting evidence suggesting that genetic and environmental risk factors interact and correlate with consequences for child eating behavior and weight. Further, neuroimaging studies are revealing that individual differences in responses to visual food cues, as well as to small tastes and larger amounts of food, across a number of brain regions involved in reward/motivation, cognitive control and other functions, may contribute to individual variation in appetitive behavior. Growing evidence also suggests that variation on psychometric measures of appetite is associated with regional differences in brain structure, and differential patterns of resting state functional connectivity. Large prospective studies beginning in infancy promise to enrich our understanding of neural and other biological underpinnings of appetite and obesity development in early life, and how the interplay between genetic and environmental factors affects appetitive systems. The biobehavioral susceptibility model of obesity development and maintenance outlined in this narrative review has implications for prevention and treatment of obesity in childhood.

A pilot retrospective study of a physician-directed and genomics-based model for precision lifestyle medicine

Precision lifestyle medicine is a relatively new field in primary care, based on the hypothesis that genetic predispositions influence an individual's response to specific interventions such as diet, exercise, and prescription medications. Despite the increase in commercially available genomic testing, few studies have investigated effects of a physician-directed program to optimize chronic disease using genomics-based precision medicine. We performed an pilot, observational cohort study to evaluate effects of the Wild Health program, a physician and health coach service offering genomics-based lifestyle and medical interventions, on biomarkers indicative of chronic disease. 871 patients underwent genomic testing, biomarker testing, and ongoing health coaching after initial medical consultation by a physician. Improvements in several clinically relevant out-of-range biomarkers at baseline were identified in a large proportion of patients treated through lifestyle intervention without the use of prescription medication. Notably, normalization of several biomarkers associated with chronic disease occurred in 47.5% (hemoglobin A1c [HbA1c]), 33.3% (low density lipoprotein particle number [LDL-P]), and 33.2% (C-reactive protein [CRP]). However, due to the inherent limitations of our observational study design and use of retrospective data, ongoing work will be crucial for continuing to shed light on the effectiveness of physician-led, genomics-based lifestyle coaching programs. Future studies would benefit from implementing a randomized controlled study design, tracking specific interventions, and evaluating physiological data, such as BMI.

Heightened sensitivity to high-calorie foods in children at risk for obesity: insights from behavior, neuroimaging, and genetics

Pediatric obesity is a major public health concern. Genetic susceptibility and increased availability of energy-dense food are known risk factors for obesity. However, the extent to which these factors jointly bias behavior and neural circuitry towards increased adiposity in children remains unclear. While undergoing fMRI, 108 children (ages 5-11y) performed a food-specific go/no-go task. Participants were instructed to either respond ("go") or inhibit responding ("no-go") to images of food or toys. Half of the runs depicted high-calorie foods (e.g., pizza) whereas the other half depicted low-calorie foods (e.g., salad). Children were also genotyped for a DNA polymorphism associated with energy intake and obesity (FTO rs9939609) to examine the influence of obesity risk on behavioral and brain responses to food. Participants demonstrated differences in behavioral sensitivity to high- and low-calorie food images depending on task demands. Participants were slower but more accurate at detecting high- (relative to low-) calorie foods when responding to a neutral stimulus (i.e., toys) and worse at detecting toys when responding to high-calorie foods. Inhibition failures were accompanied by salience network activity (anterior insula, dorsal anterior cingulate cortex), which was driven by false alarms to food images. Children at a greater genetic risk for obesity (dose-dependent model of the FTO genotype) demonstrated pronounced brain and behavioral relationships such that genetic risk was associated with heightened sensitivity to high-calorie food images and increased anterior insula activity. These findings suggest that high-calorie foods may be particularly salient to children at risk for developing eating habits that promote obesity.

Cell Differentiation and Aging Lead To Up-Regulation of FTO, While the ALKBH5 Protein Level Was Stable During Aging but Up-Regulated During in vitro-Induced Cardiomyogenesis

FTO and ALKBH5 proteins are essential erasers of N6-adenosine methylation in RNA. We studied how levels of FTO and ALKBH5 proteins changed during mouse embryonic development, aging, cardiomyogenesis, and neuroectodermal differentiation. We observed that aging in male and female mice was associated with FTO up-regulation in mouse hearts, brains, lungs, and kidneys, while the ALKBH5 level remained stable. FTO and ALKBH5 proteins were up-regulated during experimentally induced cardiomyogenesis, but the level of ALKBH5 protein was not changed when neuroectodermal differentiation was induced. HDAC1 depletion in mouse ES cells caused FTO down-regulation. In these cells, mRNA, carrying information from genes that regulate histone signature, RNA processing, and cell differentiation, was characterized by a reduced level of N6-adenosine methylation in specific gene loci, primarily regulating cell differentiation into neuroectoderm. Together, when we compared both RNA demethylating proteins, the FTO protein level undergoes the most significant changes during cell differentiation and aging. Thus, we conclude that during aging and neuronal differentiation, m6A RNA demethylation is likely regulated by the FTO protein but not via the function of ALKBH5.

The rs1421085 variant within FTO promotes brown fat thermogenesis

One lead genetic risk signal of obesity-the rs1421085 T>C variant within the FTO gene-is reported to be functional in vitro but lacks evidence at an organism level. Here we recapitulate the homologous human variant in mice with global and brown adipocyte-specific variant knock-in and reveal that mice carrying the C-allele show increased brown fat thermogenic capacity and resistance to high-fat diet-induced adiposity, whereas the obesity-related phenotypic changes are blunted at thermoneutrality. Both in vivo and in vitro data reveal that the C-allele in brown adipocytes enhances the transcription of the Fto gene, which is associated with stronger chromatin looping linking the enhancer region and Fto promoter. Moreover, FTO knockdown or inhibition effectively eliminates the increased thermogenic ability of brown adipocytes carrying the C-allele. Taken together, these findings identify rs1421085 T>C as a functional variant promoting brown fat thermogenesis.

Cool executive functions and their association with body mass & fatness and the FTO gene in school-aged children

The FTO gene rs9936909 polymorphism is one of the well-documented single nucleotide polymorphisms in the context of increased risk of obesity, including in children. Few studies have tested the association of the FTO gene with cognitive functions. Deficits of "cool" executive functions (EFs) are considered a potential risk factor for excessive weight. The aims of our study were to investigate whether cool EFs are associated with the Body Mass Index, the Fat Mass Index and the risk of excess body mass and overfatness in neurotypically school-aged children, and whether the FTO gene polymorphism is involved in development of this possible association. The sample consisted of 553 children aged 6-12 years old. A body composition analysis, a neuropsychological assessment of EFs, and FTO polymorphism genotyping were performed in the children studied. The study found a significant association of an interference effect in theStroop Color-Word Interference Task and the risk of excessive body fatness, but not excessive body mass. There were no explicit associations between the FTO genotype and EFs deficits. Environmental factors, and particularly low maternal education, appeared to be the strongest contributors to the increased risk of obesity.

Polymorphisms of Fat Mass and Obesity-Associated Gene in the Pathogenesis of Child and Adolescent Metabolic Syndrome

Childhood metabolic syndrome (MetS) is prevalent around the world and is associated with a high likelihood of suffering from severe diseases such as cardiovascular disease later in adulthood. MetS is associated with genetic susceptibility that involves gene polymorphisms. The fat mass and obesity-associated gene (FTO) encodes an RNA N6-methyladenosine demethylase that regulates RNA stability and molecular functions. Human FTO contains genetic variants that significantly contribute to the early onset of MetS in children and adolescents. Emerging evidence has also uncovered that FTO polymorphisms in intron 1, such as rs9939609 and rs9930506 polymorphisms, are significantly associated with the development of MetS in children and adolescents. Mechanistic studies reported that FTO polymorphisms lead to aberrant expressions of FTO and the adjacent genes that promote adipogenesis and appetite and reduce steatolysis, satiety, and energy expenditure in the carriers. The present review highlights the recent observations on the key FTO polymorphisms that are associated with child and adolescent MetS with an exploration of the molecular mechanisms underlying the development of increased waist circumference, hypertension, and hyperlipidemia in child and adolescent MetS.

Genetic predisposition to macronutrient preference and workplace food choices

Prior research identified genetic variants influencing macronutrient preference, but whether genetic differences underlying nutrient preference affect long-term food choices is unknown. Here we examined the associations of polygenic scores for carbohydrate, fat, and protein preference with 12 months' workplace food purchases among 397 hospital employees from the ChooseWell 365 study. Food purchases were obtained retrospectively from the hospital's cafeteria sales data for the 12 months before participants were enrolled in the ChooseWell 365 study. Traffic light labels, visible to employees when making purchases, measured the quality of workplace purchases. During the 12-month study period, there were 215,692 cafeteria purchases. Each SD increase in the polygenic score for carbohydrate preference was associated with 2.3 additional purchases/month (95%CI, 0.2 to 4.3; p = 0.03) and a higher number of green-labeled purchases (β = 1.9, 95%CI, 0.5-3.3; p = 0.01). These associations were consistent in subgroup and sensitivity analyses accounting for additional sources of bias. There was no evidence of associations between fat and protein polygenic scores and cafeteria purchases. Findings from this study suggest that genetic differences in carbohydrate preference could influence long-term workplace food purchases and may inform follow-up experiments to enhance our understanding of the molecular mechanisms underlying food choice behavior.

Emerging Role and Mechanism of the FTO Gene in Cardiovascular Diseases

The fat mass and obesity-associated (FTO) gene was the first obesity-susceptibility gene identified through a genome-wide association study (GWAS). A growing number of studies have suggested that genetic variants of FTO are strongly associated with the risk of cardiovascular diseases, including hypertension and acute coronary syndrome. In addition, FTO was also the first N⁶-methyladenosine (m6A) demethylase, suggesting the reversible nature of m6A modification. m6A is dynamically deposited, removed, and recognized by m6A methylases, demethylases, and m6A binding proteins, respectively. By catalyzing m6A demethylation on mRNA, FTO may participate in various biological processes by modulating RNA function. Recent studies demonstrated that FTO plays a pivotal role in the initiation and progression of cardiovascular diseases such as myocardial fibrosis, heart failure, and atherosclerosis and may hold promise as a potential therapeutic target for treating or preventing a variety of cardiovascular diseases. Here, we review the association between FTO genetic variants and cardiovascular disease risk, summarize the role of FTO as an m6A demethylase in cardiovascular disorders, and discuss future research directions and possible clinical implications.

Increased meso-striatal connectivity mediates trait impulsivity in FTO variant carriers

Objective

While variations in the first intron of the fat mass and obesity-associated gene (FTO, rs9939609 T/A variant) have long been identified as a major contributor to polygenic obesity, the mechanisms underlying weight gain in risk allele carriers still remain elusive. On a behavioral level, FTO variants have been robustly linked to trait impulsivity. The regulation of dopaminergic signaling in the meso-striatal neurocircuitry by these FTO variants might represent one mechanism for this behavioral alteration. Notably, recent evidence indicates that variants of FTO also modulate several genes involved in cell proliferation and neuronal development. Hence, FTO polymorphisms might establish a predisposition to heightened trait impulsivity during neurodevelopment by altering structural meso-striatal connectivity. We here explored whether the greater impulsivity of FTO variant carriers was mediated by structural differences in the connectivity between the dopaminergic midbrain and the ventral striatum.

Methods

Eighty-seven healthy normal-weight volunteers participated in the study; 42 FTO risk allele carriers (rs9939609 T/A variant, FTO ⁺ group: AT, AA) and 39 non-carriers (FTO ^- group: TT) were matched for age, sex and body mass index (BMI). Trait impulsivity was assessed via the Barratt Impulsiveness Scale (BIS-11) and structural connectivity between the ventral tegmental area/substantia nigra (VTA/SN) and the nucleus accumbens (NAc) was measured via diffusion weighted MRI and probabilistic tractography.

Results

We found that FTO risk allele carriers compared to non-carriers, demonstrated greater motor impulsivity (p = 0.04) and increased structural connectivity between VTA/SN and the NAc (p< 0.05). Increased connectivity partially mediated the effect of FTO genetic status on motor impulsivity.

Conclusion

We report altered structural connectivity as one mechanism by which FTO variants contribute to increased impulsivity, indicating that FTO variants may exert their effect on obesity-promoting behavioral traits at least partially through neuroplastic alterations in humans.

Fat mass and obesity-associated factor (FTO)-mediated N6-methyladenosine regulates spermatogenesis in an age-dependent manner

N6-methyladenosine (m6A) is the most prevalent reversible RNA modification in the mammalian transcriptome. It has recently been demonstrated that m6A is crucial for male germline development. Fat mass and obesity-associated factor (FTO), a known m6A demethylase, is widely expressed in human and mouse tissues and is involved in manifold biological processes and human diseases. However, the function of FTO in spermatogenesis and male fertility remains poorly understood. Here, we generated an Fto knockout mouse model using CRISPR/Cas9-mediated genome editing techniques to address this knowledge gap. Remarkably, we found that loss of Fto in mice caused spermatogenesis defects in an age-dependent manner, resulting from the attenuated proliferation ability of undifferentiated spermatogonia and increased male germ cell apoptosis. Further research showed that FTO plays a vital role in the modulation of spermatogenesis and Leydig cell maturation by regulating the translation of the androgen receptor in an m6A-dependent manner. In addition, we identified two functional mutations of FTO in male infertility patients, resulting in truncated FTO protein and increased m6A modification in vitro. Our results highlight the crucial effects of FTO on spermatogonia and Leydig cells for the long-term maintenance of spermatogenesis and expand our understanding of the function of m6A in male fertility.

Technologies, strategies, and cautions when deconvoluting genome-wide association signals: FTO in focus

Genome-wide association studies have revealed a plethora of genetic variants that correlate with polygenic conditions. However, causal molecular mechanisms have proven challenging to fully define. Without such information, the associations are not physiologically useful or clinically actionable. By reviewing studies of the FTO locus in the genetic etiology of obesity, we wish to highlight advances in the field fueled by the evolution of technical and analytic strategies in assessing the molecular bases for genetic associations. Particular attention is drawn to extrapolating experimental findings from animal models and cell types to humans, as well as technical aspects used to identify long-range DNA interactions and their biological relevance with regard to the associated trait. A unifying model is proposed by which independent obesogenic pathways regulated by multiple FTO variants and genes are integrated at the primary cilium, a cellular antenna where signaling molecules that control energy balance convene.

The Epigenetic Regulation of RNA N6-Methyladenosine Methylation in Glycolipid Metabolism

The highly conserved and dynamically reversible N6-methyladenine (m6A) modification has emerged as a critical gene expression regulator by affecting RNA splicing, translation efficiency, and stability at the post-transcriptional level, which has been established to be involved in various physiological and pathological processes, including glycolipid metabolism and the development of glycolipid metabolic disease (GLMD). Hence, accumulating studies have focused on the effects and regulatory mechanisms of m6A modification on glucose metabolism, lipid metabolism, and GLMD. This review summarizes the underlying mechanism of how m6A modification regulates glucose and lipid metabolism-related enzymes, transcription factors, and signaling pathways and the advances of m6A regulatory mechanisms in GLMD in order to deepen the understanding of the association of m6A modification with glycolipid metabolism and GLMD.

Gene-diet interaction in response to defatted flaxseed flour supplementation on obesity-related traits in Chinese overweight and obese adults: A randomized controlled trial

Effects of dietary fiber on obesity-related traits in previous studies were inconsistent. The aim of the present study was to explore whether variants in genes related to satiety and appetite can modulate the effect of dietary fiber on obesity-related traits. Fifty-one overweight or obese adults were randomly allocated to two groups to consume control biscuits (n = 24) or biscuits containing defatted flaxseed flour (n = 27) at breakfast for 8 wk. Four single-nucleotide polymorphisms related to satiety and appetite were genotyped: rs11076023 on the FTO gene, rs16147 on the NPY gene, rs155971 on the PCSK1 gene, and rs6265 on the BDNF gene. A linear regression model was used to evaluate the gene-diet interaction between obesity-related traits. Compared with control biscuits, defatted flaxseed-flour biscuits significantly reduced body weight (P = 0.001) and body mass index (BMI) (P = 0.001) in A-allele carriers (AA + AT) of rs11076023 on the FTO gene but not in non-carriers (TT) (P for the interaction = 0.005 and 0.006) and decreased fasting serum glucose in participants with CC genotype (P = 0.019) but had less effect in T-allele carriers (TT + TC) (P = 0.021) of rs16147 on the NPY gene (P for the interaction = 0.002). Compared with the control biscuits, defatted flaxseed flour significantly reduced body weight (P < 0.001) in T-allele carriers (TT + TC) of rs155971 on the PCSK1 gene but not in non-carriers (CC) (P for the interaction = 0.041) and reduced body weight (P = 0.001) and BMI (P < 0.001) in A-allele carriers (AA + AG) of rs6265 on the BDNF gene but not non-carriers (GG) (P for the interaction = 0.017 and 0.018). Variants of genes related to satiety and appetite could modulate the effect of defatted flaxseed flour on obesity-related traits.

RNA Modifications in Cancer Metabolism and Tumor Microenvironment

RNA modifications have recently been recognized as essential posttranscriptional regulators of gene expression in eukaryotes. Investigations over the past decade have revealed that RNA chemical modifications have profound effects on tumor initiation, progression, refractory, and recurrence. Tumor cells are notorious for their robust plasticity in response to the stressful microenvironment and undergo metabolic adaptations to sustain rapid cell proliferation, which is termed as metabolic reprogramming. Meanwhile, cancer-associated metabolic reprogramming leads to substantial alterations of intracellular and extracellular metabolites, which further reshapes the tumor microenvironment (TME). Moreover, cancer cells compete with tumor-infiltrating immune cells for the limited nutrients to maintain their proliferation and function in the TME. In this chapter, we review recent interesting findings on the engagement of epitranscriptomic pathways, especially the ones associated with N6-methyladenosine (m6A), in the regulation of cancer metabolism and the surrounding microenvironment. We also discuss the promising therapeutic approaches targeting RNA modifications for anti-tumor therapy.

Systematic review and meta-analysis of breastfeeding and later overweight or obesity expands on previous study for World Health Organization

AIM

To update a systematic review and meta-analysis of the association of breastfeeding with overweight or obesity that had been commissioned by the World Health Organization. We also assessed the likelihood of residual confounding.

METHODS

Two independent reviewers searched MEDLINE, LILACS and Web of Science for manuscripts published between August 2014 and May 2021. Studies that only evaluated infants were excluded. Random-effects models were used to pool the estimates.

RESULTS

The review comprised 159 studies with 169 estimates on the association of breastfeeding with overweight or obesity, and most of the studies were carried out among individuals aged 1-9 years (n = 130). Breastfeeding protected against overweight or obesity (pooled odds ratio:0.73, 95% confidence interval:0.71; 0.76). And, even among the 19 studies that were less susceptible to publication bias, residual confounding and misclassification, a benefit was observed (pooled odds ratio:0.85, 95% confidence interval:0.77; 0.93). Among those studies that were clearly susceptible to positive confounding by socioeconomic status, a benefit of breastfeeding was observed even after adjusting for socioeconomic status (pooled odds ratio:0.76, 95% confidence interval: 0.69; 0.83).

CONCLUSION

Breastfeeding reduced the odds of overweight or obesity, and this association was unlikely to be due to publication bias and residual confounding.

FTO Common Obesity SNPs Interact with Actionable Environmental Factors: Physical Activity, Sugar-Sweetened Beverages and Wine Consumption

Genetic background is estimated to play >50% in common obesity etiology. FTO single nucleotide polymorphisms (SNPs) are strongly associated with BMI, typically in European cohorts. We investigated the interaction of common FTO SNPs with actionable environmental factors, namely physical activity, sugar-sweetened beverages (SSB) and wine consumption, and verified FTO common SNPs predisposition to obesity in the Israeli population. Adults’ (>18 years old, n = 1720) FTO common SNPs data and lifestyle and nutrition habits questionnaires were analyzed using binary logistic regression models, adjusted for confounding variables (age, sex) assuming dominant, recessive and additive genetic models. Eighteen FTO SNPs were associated with significant increased obesity risk and interacted with physical activity (p < 0.001), wine consumption (p < 0.014) and SSB consumption (p < 0.01). Inactive rs9939609 risk-allele carriers had significantly higher obesity risk compared to their active counterparts (OR = 2.54, 95% CI 1.91−3.39 and OR = 3.77, 95% CI 2.47−5.75; p < 0.001 with 3.1 and 3.5 BMI increment for heterozygotes and homozygotes, respectively). SSB consumption (≥1 serving/day) significantly raised obesity risk and wine consumption (1−3 drinks/weekly) significantly lowered obesity risk for rs9939609 risk-allele carriers (OR = 1.54, 95% CI 1.05−2.27; p = 0.028 and OR = 0.61, 95% CI 0.47−0.79; p < 0.001, respectively). Our findings demonstrate that actionable lifestyle factors modify the common FTO obesity risk in predisposed carriers, and they have personal and public health implications.

From food preference development to responsive feeding - Selective studies to commemorate the life and work of Dr Leann Birch

Dr Leann Birch was a pioneer in conducting research on infant and child eating behaviour. At the beginning of her research career, Leann recognised a significant gap in the developmental psychology literature, namely that few studies had been conducted to understand infant eating and feeding behaviours. This seems an unusual omission given that food intake is essential and that developmental milestones from milk to solids, and from being fed to becoming an autonomous eater, are obvious to most caregivers. Leann paved the way for interdisciplinary research from psychology, paediatrics and public health to explore and apply this knowledge to infant and child appetite, eating behaviour, dietary patterns, food preferences, and obesity risk. Early studies in her laboratory demonstrated that children form food preferences through experience and socialisation. Experiments published in 1979 tested the role of familiarisation through repeat exposure, and the impact of instrumental and social learning on the acquisition of food preferences. In 1984, a presentation given to the British Feeding and Drinking Group (BFDG) in Brighton set out three organising principles for understanding how children acquire food preferences: genetically pre-programmed behavioural propensities; social constraints on experience with food; and social transmission resulting from direct social interaction. Building on these three organising principles, research on child eating behaviour has flourished, including the intersection between individual differences, food experience and environmental influences on children's food preferences, energy regulation, and weight outcomes. In this review, the initial groundwork set out by Leann Birch on food preference development in children is considered followed by a discussion of how this has since inspired an interdisciplinary, international and expanding field of research on children's food intake, appetite and body weight regulation.

Genetic determinants of metabolic biomarkers and their associations with cardiometabolic traits in Hispanic/Latino adolescents

BACKGROUND

Metabolic regulation plays a significant role in energy homeostasis, and adolescence is a crucial life stage for the development of cardiometabolic disease (CMD). This study aims to investigate the genetic determinants of metabolic biomarkers-adiponectin, leptin, ghrelin, and orexin-and their associations with CMD risk factors.

METHODS

We characterized the genetic determinants of the biomarkers among Hispanic/Latino adolescents of the Santiago Longitudinal Study (SLS) and identified the cumulative effects of genetic variants on adiponectin and leptin using biomarker polygenic risk scores (PRS). We further investigated the direct and indirect effect of the biomarker PRS on downstream body fat percent (BF%) and glycemic traits using structural equation modeling.

RESULTS

We identified putatively novel genetic variants associated with the metabolic biomarkers. A substantial amount of biomarker variance was explained by SLS-specific PRS, and the prediction was improved by including the putatively novel loci. Fasting blood insulin and insulin resistance were associated with PRS for adiponectin, leptin, and ghrelin, and BF% was associated with PRS for adiponectin and leptin. We found evidence of substantial mediation of these associations by the biomarker levels.

CONCLUSIONS

The genetic underpinnings of metabolic biomarkers can affect the early development of CMD, partly mediated by the biomarkers.

IMPACT

This study characterized the genetic underpinnings of four metabolic hormones and investigated their potential influence on adiposity and insulin biology among Hispanic/Latino adolescents. Fasting blood insulin and insulin resistance were associated with polygenic risk score (PRS) for adiponectin, leptin, and ghrelin, with evidence of some degree of mediation by the biomarker levels. Body fat percent (BF%) was also associated with PRS for adiponectin and leptin. This provides important insight on biological mechanisms underlying early metabolic dysfunction and reveals candidates for prevention efforts. Our findings also highlight the importance of ancestrally diverse populations to facilitate valid studies of the genetic architecture of metabolic biomarker levels.

FTO m6A Demethylase in Obesity and Cancer: Implications and Underlying Molecular Mechanisms

Fat mass and obesity-associated protein (FTO) is the first reported RNA N6-methyladenosine (m6A) demethylase in eukaryotic cells. m6A is considered as the most abundant mRNA internal modification, which modulates several cellular processes including alternative splicing, stability, and expression. Genome-wide association studies (GWAS) identified single-nucleotide polymorphisms (SNPs) within FTO to be associated with obesity, as well as cancer including endometrial cancer, breast cancer, pancreatic cancer, and melanoma. Since the initial classification of FTO as an m6A demethylase, various studies started to unravel a connection between FTO’s demethylase activity and the susceptibility to obesity on the molecular level. FTO was found to facilitate adipogenesis, by regulating adipogenic pathways and inducing pre-adipocyte differentiation. FTO has also been investigated in tumorigenesis, where emerging studies suggest m6A and FTO levels are dysregulated in various cancers, including acute myeloid leukemia (AML), glioblastoma, cervical squamous cell carcinoma (CSCC), breast cancer, and melanoma. Here we review the molecular bases of m6A in tumorigenesis and adipogenesis while highlighting the controversial role of FTO in obesity. We provide recent findings confirming FTO’s causative link to obesity and discuss novel approaches using RNA demethylase inhibitors as targeted oncotherapies. Our review aims to confirm m6A demethylation as a risk factor in obesity and provoke new research in FTO and human disorders.

The FTO rs9939609 Variant Is Associated with Cardiometabolic Disease Risk and Dietary Energy Intakes in Children with Mental Health Disorders

Background

Second-generation antipsychotics (SGAs) are used to treat children for mental health disorders but in some children they cause cardiometabolic complications including weight gain and type 2 diabetes. Genetic variants can place a child at risk of developing these metabolic complications. The fat mass and obesity-associated (FTO) rs9939609 A allele has been associated with obesity and dietary energy intakes in healthy children but its relation to metabolic complications in SGA-treated children is not known.

Objectives

This study investigated the association of the FTO rs9939609 variant and SGA treatment with cardiometabolic complications and dietary intakes in children with mental health disorders.

Methods

A cross-sectional population of children (≤18 y; n = 506) with mental health disorders that were SGA-treated (n = 197) and SGA-naïve (n = 309) were recruited through the Department of Psychiatry at BC Children's Hospital. Dietary intakes were estimated using 3-d food records in a subset of children (n = 73).

Results

Genotype frequencies were not different between SGA-treated (TT genotype 42.6%, TA genotype 38.6%, AA genotype 18.8%) and SGA-naïve (TT 41.1%, TA 39.5%, AA 19.4%) children. Children with the A allele had lower BMI z-sores compared with the TT genotype (0.84 ± 1.19 compared with 1.19 ± 1.36; P = 0.005, adjusted for ethnicity). We observed an interaction between FTO genotype and SGA status on fasting glucose (P = 0.036). SGA-naïve children with the A allele had higher fasting glucose than those with the TT genotype (4.96 ± 0.35 compared with 4.81 ± 0.35 mmol/L; P = 0.001), in adjusted models (age, sex, ethnicity, and BMI z-score). This was not observed in SGA-treated children. Children with the A allele had higher daily total energy intakes compared with the TT genotype (1994 ± 619 compared with 1814 ± 484 kcal/d; P = 0.048), in adjusted models (age, sex, ethnicity, and BMI z-score); no effect of SGA-treatment was observed.

Conclusions

Our findings suggest the A allele of the FTO rs9939609 variant is associated with higher BMI in children with mental health disorders, but only in those not treated with SGAs.

Genetics, epigenetics and transgenerational transmission of obesity in children

Sedentary lifestyle and consumption of high-calorie foods have caused a relentless increase of overweight and obesity prevalence at all ages. Its presently epidemic proportion is disquieting due to the tight relationship of obesity with metabolic syndrome and several other comorbidities which do call for urgent workarounds. The usual ineffectiveness of present therapies and failure of prevention campaigns triggered overtime a number of research studies which have unveiled some relevant aspects of obesity genetic and epigenetic inheritable profiles. These findings are revealing extremely precious mainly to serve as a likely extra arrow to allow the clinician's bow to achieve still hitherto unmet preventive goals. Evidence now exists that maternal obesity/overnutrition during pregnancy and lactation convincingly appears associated with several disorders in the offspring independently of the transmission of a purely genetic predisposition. Even the pre-conception direct exposure of either father or mother gametes to environmental factors can reprogram the epigenetic architecture of cells. Such phenomena lie behind the transfer of the obesity susceptibility to future generations through a mechanism of epigenetic inheritance. Moreover, a growing number of studies suggests that several environmental factors such as maternal malnutrition, hypoxia, and exposure to excess hormones and endocrine disruptors during pregnancy and the early postnatal period may play critical roles in programming childhood adipose tissue and obesity. A deeper understanding of how inherited genetics and epigenetics may generate an obesogenic environment at pediatric age might strengthen our knowledge about pathogenetic mechanisms and improve the clinical management of patients. Therefore, in this narrative review, we attempt to provide a general overview of the contribution of heritable genetic and epigenetic patterns to the obesity susceptibility in children, placing a particular emphasis on the mother-child dyad.

Causative Mechanisms of Childhood and Adolescent Obesity Leading to Adult Cardiometabolic Disease: A Literature Review

The past few decades have shown a worrisome increase in the prevalence of obesity and its related illnesses. This increasing burden has a noteworthy impact on overall worldwide mortality and morbidity, with significant economic implications as well. The same trend is apparent regarding pediatric obesity. This is a particularly concerning aspect when considering the well-established link between cardiovascular disease and obesity, and the fact that childhood obesity frequently leads to adult obesity. Moreover, most obese adults have a history of excess weight starting in childhood. In addition, given the cumulative character of both time and severity of exposure to obesity as a risk factor for associated diseases, the repercussions of obesity prevalence and related morbidity could be exponential in time. The purpose of this review is to outline key aspects regarding the current knowledge on childhood and adolescent obesity as a cardiometabolic risk factor, as well as the most common etiological pathways involved in the development of weight excess and associated cardiovascular and metabolic diseases.

Irx3 and Irx5 - Novel Regulatory Factors of Postnatal Hypothalamic Neurogenesis

The hypothalamus is a brain region that exhibits highly conserved anatomy across vertebrate species and functions as a central regulatory hub for many physiological processes such as energy homeostasis and circadian rhythm. Neurons in the arcuate nucleus of the hypothalamus are largely responsible for sensing of peripheral signals such as leptin and insulin, and are critical for the regulation of food intake and energy expenditure. While these neurons are mainly born during embryogenesis, accumulating evidence have demonstrated that neurogenesis also occurs in postnatal-adult mouse hypothalamus, particularly in the first two postnatal weeks. This second wave of active neurogenesis contributes to the remodeling of hypothalamic neuronal populations and regulation of energy homeostasis including hypothalamic leptin sensing. Radial glia cell types, such as tanycytes, are known to act as neuronal progenitors in the postnatal mouse hypothalamus. Our recent study unveiled a previously unreported radial glia-like neural stem cell (RGL-NSC) population that actively contributes to neurogenesis in the postnatal mouse hypothalamus. We also identified Irx3 and Irx5, which encode Iroquois homeodomain-containing transcription factors, as genetic determinants regulating the neurogenic property of these RGL-NSCs. These findings are significant as IRX3 and IRX5 have been implicated in FTO-associated obesity in humans, illustrating the importance of postnatal hypothalamic neurogenesis in energy homeostasis and obesity. In this review, we summarize current knowledge regarding postnatal-adult hypothalamic neurogenesis and highlight recent findings on the radial glia-like cells that contribute to the remodeling of postnatal mouse hypothalamus. We will discuss characteristics of the RGL-NSCs and potential actions of Irx3 and Irx5 in the regulation of neural stem cells in the postnatal-adult mouse brain. Understanding the behavior and regulation of neural stem cells in the postnatal-adult hypothalamus will provide novel mechanistic insights in the control of hypothalamic remodeling and energy homeostasis.

Polymorphisms on rs9939609 FTO and rs17782313 MC4R genes in children and adolescent obesity: A systematic review

The aim of this review was to assess whether the presence of rs9939609 and rs17782313 polymorphisms increase the risk for obesity among children and adolescents. This systematic review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist and it was registered in PROSPERO. The search was performed in the PubMed/Medline, The Cochrane Library, and Web of Science databases. The risk of bias of the studies was accessed using the Newcastle-Ottawa scale and JBI Critical Appraisal Checklist for Analytical. The search of the databases retrieved 859 references. Twelve studies were eligible to be included in this systematic review. Five studies founded a positive association between overweight and obesity in children and adolescents with the presence of the rs17783213 and four studies with rs9939609. Three studies did not find an association between overweight and obesity in children and adolescents with the presence of rs17782313 or rs9939609. One found a protective effect for obesity in individuals with risk A allele referring to rs9939609, one found a synergistic effect in relation to the presence of polymorphisms rs17782313 and rs9939609 for obese phenotype, and one observed that the presence together of the rs9939609, rs17782313, and rs12970134 MC4R were significant for the presence of obesity in children and adolescents. The results suggest that depending on the population evaluated and ethnicity, the polymorphisms rs17782313 and rs9939609 could be associated with overweight and obesity in children and adolescents.