Gene-Environment Interplay in Child Eating Behaviors: What the Role of "Nature" Means for the Effects of "Nurture".

PURPOSE OF REVIEW: This narrative review describes the evidence for both genetic and environmental influences on child appetitive traits and suggests ways of thinking about how these interact and correlate to influence how a child eats. RECENT FINDINGS: Emerging evidence from social network analysis, and from longitudinal studies questioning the direction of association between parent feeding behaviors and child obesity risk, suggest that children's genes may shape the environmental risk for obesity that they are exposed to. There is strong evidence that child appetitive traits are both heritable and shaped by the environment. Instead of thinking about how genetic and environmental factors operate independently on each appetitive trait, research needs to expand the current paradigm to examine how genes and environments interact and shape each other.

Long-term impact of early life events on physiology and behaviour.

This review discusses the effects of stress and nutrition throughout development and summarises studies investigating how exposure to stress or alterations in nutrition during the pre-conception, prenatal and early postnatal periods can affect the long-term health of an individual. In general, the data presented here suggest that that anything signalling potential adverse conditions later in life, such as high levels of stress or low levels of food availability, will lead to alterations in the offspring, possibly of an epigenetic nature, preparing the offspring for these conditions later in life. However, when similar environmental conditions are not met in adulthood, these alterations may have maladaptive consequences, resulting in obesity and heightened stress sensitivity. The data also suggest that the mechanism underlying these adult phenotypes might be dependent on the type and the timing of exposure.

Association of maternal and child nutritional status in Brazil: a population based cross-sectional study.

BACKGROUND: Although child undernutrition and stunting has been decreasing worldwide while obesity rates increase, these extreme conditions might coexist in families from low- and middle-income countries. We examined the association between maternal and child anthropometric indicators using a population representative sample. METHODS: 4,258 non-pregnant women and their children <60 months who participated in the 2006 Brazilian Demographic Health Survey. We compared the distributions of two nutritional indexes of children, height-for-age (HAZ) and body mass index-for age (BAZ) z-scores, by categories of maternal height, body mass index (BMI), and waist circumference (WC). Adjusted mean differences and 95% confidence intervals (95% CI) were estimated from linear regression, taking into account the complex survey design. We also examined the associations of maternal anthropometry with the prevalence of child stunting (HAZ<-2) and overweight/obesity (BAZ>2). RESULTS: HAZ was positively associated with maternal height and WC in a linear fashion. After adjustment, for sociodemographic characteristics, children whose mothers' height was<145 cm had 1.2 lower HAZ than children whose mothers were ≥160 cm tall (p-trend<0.0001). After further adjustment for maternal height and maternal BMI, children of mothers with a waist circumference ≥88 cm had 0.3 higher HAZ than those of mothers with WC<80 cm (p-trend<0.01). Adjusted prevalence ratios and 95% CI for stunting by the categories of maternal height (<145, 145-149, 150-154, 155-159 and ≥160 cm) were, respectively, 2.95 (1.51;5.77), 2.29 (1.33;3.93), 1.09 (0.63;1.87), and 0.89 (0.45;1.77), (p-trend = 0.001). BAZ was positively associated with maternal BMI and WC. CONCLUSION: We observed a strong, positive association of maternal and child nutritional status. Mothers of low stature had children with lower stature, mothers with central obesity had taller children, and mothers with overall or abdominal obesity had children with higher BAZ.

Life Course Perspective: evidence for the role of nutrition.

The "Life Course Perspective" proposes that environmental exposures, including biological, physical, social, and behavioral factors, as well as life experiences, throughout the entire life span, influence health outcomes in current and future generations. Nutrition, from preconception to adulthood, encompasses all of these factors and has the potential to positively or negatively shape the individual or population health trajectories and their intergenerational differences. This paper applies the T2E2 model (timing, timeline, equity and environment), developed by Fine and Kotelchuck, as an overlay to examine advances in nutritional science, as well as the complex associations between life stages, nutrients, nutrigenomics, and access to healthy foods, that support the life course perspective. Examples of the application of nutrition to each of the four constructs are provided, as well as a strong recommendation for inclusion of nutrition as a key focal point for all health professionals as they address solutions to optimize health outcomes, both domestically and internationally. The science of nutrition provides strong evidence to support the concepts of the life course perspective. These findings lend urgency to the need to improve population health across the life span and over generations by ensuring ready access to micronutrient-dense foods, opportunities to balance energy intake with adequate physical activity and the need for biological, social, physical, and macro-level environments that support critical phases of human development. Recommendations for the application of the life course perspective, with a focus on the emerging knowledge of nutritional science, are offered in an effort to improve current maternal and child health programs, policies, and service delivery.

Child food neophobia is heritable, associated with less compliant eating, and moderates familial resemblance for BMI.

OBJECTIVE: The heritability of food neophobia, the tendency to avoid new foods, was tested in 4-7-year-old twins. We also examined whether food neophobia is associated with parent-child feeding relations or child body fat. DESIGN AND METHODS: 66 same-sex twin pairs, including 37 monozygotic (MZ) and 29 dizygotic (DZ) pairs were studied. Food neophobia was assessed by parent questionnaire (Child Food Neophobia Scale, CFNS), as were child-feeding practices and "division of responsibility" feeding relations. Child anthropometry and percent body fat were directly measured. RESULTS: MZ and DZ twin pair correlations for food neophobia were r = 0.71 and r = -0.01, respectively: heritability= 72%. Greater food neophobia was associated with reduced child eating compliance of prompted foods (P < 0.001) reduced eating compliance of initially refused foods (P < 0.001), and--among girls only--fewer parental food demands (P = 0.01). Interestingly, the correlation between maternal BMI and child BMI z-score was significant only for children high (P = 0.03), but not low (P = 0.55), in food neophobia. CONCLUSION: Child food neophobia, a highly heritable trait previously linked to emotionality, was associated with less compliant parent-child feeding relations. Strategies to combat food neophobia and foster more harmonious feeding relationships may have a role in obesity prevention.

A twin study of self-regulatory eating in early childhood: estimates of genetic and environmental influence, and measurement considerations.

OBJECTIVE: Children differ greatly in their ability to self-regulate food intake for reasons that are poorly understood. This laboratory-based twin study tested the genetic and environmental contributions to self-regulatory eating and body fat in early childhood. METHODS: A total of 69 4-7 year-old same-sex twin pairs, including 40 monozygotic and 29 dizygotic pairs, were studied. Self-regulatory eating was operationalized as the percentage compensation index (COMPX%), assessed by a 'preload' challenge in which lunch intake was measured following a low- (3 kcal) or high-calorie (159 kcal) drink. Body fat indexes also were measured. The familial association for COMPX% was estimated by an intraclass correlation, and biometric analyses estimated heritability. RESULTS: Children ate more at lunch following the low- compared with high-energy preload (P<0.001), although variability in COMPX% was considerable. Compensation was significantly poorer among African American and Hispanic compared with European American children, and among girls compared with boys. There was a familial association for self-regulatory eating (ρ = 0.23, P = 0.03) but no significant genetic component. In all, 22% of the variance in COMPX% was due to shared environmental 'household' factors, with the remaining variance attributable to child-specific 'unique' or 'random' environments. Poorer self-regulatory eating was associated with greater percent body fat (r = -0.21, P = 0.04). CONCLUSIONS: Self-regulatory eating was influenced by environmental factors, especially those differing among siblings. The absence of a significant genetic effect may reflect the age of the sample or could be artifactual due to measurement issues that need to be considered in future studies.

Nutrition and bone growth in pediatrics.

Children's growth is a hallmark of their normal development and the association between nutrition and linear growth in children is well accepted. Growth requires an adequate supply of many different nutritional factors, some form the "building materials," whereas others play regulatory roles. In this article we describe the growth of the growth plate and discuss the role of nutritional affected hormones on this process. In addition we describe the effect of local regulators and nutritional factors on the growth process and suggest the involvement of new regulatory factors in the translation of nutrition to growth.

Interaction effects between total energy and macronutrient intakes and angiotensin-converting enzyme 1 ( ACE) I/D polymorphism on adiposity-related phenotypes in toddlers and preschoolers: the Growth, Exercise and Nutrition Epidemiological Study in preSchoolers: the GENESIS study. [corrected].

The aim of the present study was to investigate the interaction between the angiotensin-converting enzyme 1 (ACE) I/D polymorphism and energy and macronutrient intakes on adiposity-related phenotypes among toddlers and preschoolers. A representative sample of 2374 Greek children aged 1 to 5 years old was examined (Growth, Exercise and Nutrition Epidemiological Study in preSchoolers (GENESIS)). Dietary and anthropometric (i.e. BMI, waist circumference (WC)) assessments were carried out using standard procedures. DNA samples were obtained from 2102 children and were genotyped for the ACE I/D polymorphism. Among the entire population, 17 % were 'at risk of overweight' and a similar percentage were 'overweight'. The frequencies of the II, ID and DD genotypes were 16, 46 and 38 %, respectively. Significant interactions were found between the ACE I/D polymorphism and total energy intake on WC (P = 0.004 for interaction) and the ACE I/D polymorphism and protein intake on BMI and being overweight (P < 0.05 for interaction). Furthermore, it was found that the ACE I/D polymorphism may modify the effect of fat intake on WC and BMI, but this interaction disappeared after adjustment for additional potential confounders. Stratified analyses revealed that total energy is correlated with WC and protein intake is associated with BMI and being overweight only among carriers of the D-allele (i.e. DD or ID genotypes). These results suggest that the ACE I/D polymorphism may act as a modifying factor in the response of adiposity-related phenotypes to diet.

Genetic and shared environmental influences on children's 24-h food and beverage intake: sex differences at age 7 y.

BACKGROUND: The genetics of habitual food and beverage intake in early childhood is poorly understood. OBJECTIVE: The objective was to test the magnitude of genetic and environmental influences on 24-h food and beverage intake in 7-y-old children. The association between intake of specific food-beverage categories and child body mass index (BMI; in kg/m(2)) was also tested. DESIGN: A classic twin design was conducted, using the MacArthur Longitudinal Study of Twins. There were 792 children, including 396 boys from 102 monozygotic and 96 dizygotic twin pairs and 396 girls from 112 monozygotic and 86 dizygotic twin pairs; Children's 24-h dietary intake was estimated by parental recall, from which 9 composite food-beverage categories were derived. Height and weight were converted to BMI. Biometrical analyses of children's daily intake of food-beverage categories and BMI were conducted. RESULTS: There was consistent evidence of genetic influences on children's 24-h intake of food and beverages (servings/d), especially among boys. Seven categories showed significant heritability estimates among boys, ranging from 12% (fish and lemon) to 79% (peanut butter and jelly). Only 3 categories showed significant heritability estimates among girls, ranging from 20% (bread and butter) to 56% (fish and lemon). BMI showed a genetic correlation only with bread and butter intake in girls. CONCLUSION: The magnitude of genetic and environmental influences on children's 24-h food and beverage intake differed for boys and girls, which suggests sex differences in the development of eating patterns. Heritability estimates were generally large, although other eating phenotypes may be necessary for identifying genetic correlations with adiposity.

Genetic and environmental determinants of children's food preferences.

Omnivores have the advantage of a variety of food options but face a challenge in identifying foods that are safe to eat. Not surprisingly, therefore, children show a relative aversion to new foods (neophobia) and a relative preference for familiar, bland, sweet foods. While this may in the past have promoted survival, in the modern food environment it could have an adverse effect on dietary quality. This review examines the evidence for genetic and environmental factors underlying individual differences in children's food preferences and neophobia. Twin studies indicate that neophobia is a strongly heritable characteristic, while specific food preferences show some genetic influence and are also influenced by the family environment. The advantage of the malleability of human food preferences is that dislike of a food can be reduced or even reversed by a combination of modelling and taste exposure. The need for effective guidance for parents who may be seeking to improve the range or nutritional value of foods accepted by their children is highlighted.

Leucine 7 to proline 7 polymorphism in the neuropeptide Y gene and changes in serum lipids during a family-based counselling intervention among school-aged children with a family history of CVD.

OBJECTIVE: To compare whether serum lipids and their changes during a health education intervention are associated with the Leu7Pro polymorphism in the signal peptide part of neuropeptide Y (NPY) in children with normal weight and in those with overweight. DESIGN: An intervention study. SETTING: A family-based intervention of risk factors for prevention of CHD in Finland. SUBJECTS: Subjects were 443 children with a family history of CVD participating in family-based health education. The children were divided into two groups according to NPY genotype: children with Leu7/Pro7 or Pro7/Pro7 genotype (n 50) and children with Leu7/Leu7 genotype (n 393). The final sample of the follow-up study included 353 (80 %) children (Pro7 allele carriers, n 43; Leu7/Leu7, n 310). RESULTS: At baseline, the Leu7Pro polymorphism was not associated with serum lipid values after adjustment for body weight in boys or girls. There was a significant interaction of NPY genotype group by time and body weight (P = 0.043 for three-way interaction: time x NPY genotype x body weight) in LDL-cholesterol (LDL-C) concentration among boys. LDL-C decreased among boys with normal weight in both NPY groups and in overweight boys with the Leu7/Leu7 genotype, whereas it increased in overweight boys with the Pro7 allele. Two-way interaction (time x NPY genotype) showed no significant differences in changes of serum lipids between the NPY genotype groups among boys or girls. CONCLUSIONS: The Leu7Pro polymorphism may be associated with dietary response to LDL-C concentration in overweight boys with a family history of early-onset CVD.