Lower birth weight is associated with alterations in dietary intake in adolescents independent of genetic factors: A twin study

Accumbal μ-opioid receptors and salt taste-elicited hedonic responses in a rodent model of prenatal adversity, and their correlates using human functional genomics

Prenatal adversity is associated with behavioral obesogenic features such as preference for palatable foods. Salt appetite may play a role in the development of adiposity and its consequences in individuals exposed to prenatal adversity, and sodium consumption involves individual differences in accumbal µ-opioid receptors function. We investigated the hedonic responses to salt and the levels of µ-opioid receptors and tyrosine hydroxylase in the nucleus accumbens (Nacc) of pups from an animal model of prenatal dietary restriction. In children, we evaluated the interaction between fetal growth and the genetic background associated with the accumbal µ-opioid receptor gene (OPRM1) expression on sodium consumption during a snack test. Sprague-Dawley dams were randomly allocated from pregnancy day 10 to receive an ad libitum (Adlib) or a 50% restricted (FR) diet. The pups' hedonic responses to a salt solution (NaCl 2%) or water were evaluated on the first day of life. FR and Adlib pups differ in their hedonic responses to salt, and there were decreased levels of accumbal µ-opioid and p-µ-opioid receptors in FR pups. In humans, a test meal and genotyping from buccal epithelial cells were performed in 270 children (38 intrauterine growth restricted-IUGR) at 4 years old from a Canadian prospective cohort (MAVAN). The OPRM1 genetic score predicted the sodium intake in IUGR children, but not in controls. The identification of mechanisms involved in the brain response to prenatal adversity and its consequences in behavioral phenotypes and risk for chronic diseases later in life is important for preventive and therapeutic purposes.

The Association Between Birth Weight and Fat, Sugar, and Vegetable Consumption in a National Sample of U.S. Preschool Age Children

INTRODUCTION

Adverse prenatal development is a contributor to obesity susceptibility in children. Dietary behavior is one mechanism through which adverse prenatal development may promote obesity, but evidence for the role of prenatal overnutrition in dietary intake in young children is scant.

METHODS

We used data from the National Health and Nutrition Examination Survey 2009-2014. Our study sample included 1782 U.S. children 2-5 years old with available birth weight and two 24-h dietary recalls. We used linear and Poisson regression to examine the association of birth weight (LBW < 2500 g, HBW > 4100 g) and 2-day average intake of dietary variables. We tested interactions between birthweight and breastfeeding (breastfed > 5 months vs. not breastfed or breastfed 0-5 months), and report breastfeeding-specific results.

RESULTS

In multivariable regression analysis, in boys, LBW was associated with 2.4 (95% CI - 4.3, - 0.5) lower percent of kcal from solid fat; lower sugar intake, marginally lower saturated and total fat intake, and 0.6 cup (95% CI 0.1, 1.0) greater vegetable consumption; HBW was marginally associated with lower fat. Birth weight was unrelated to diet in girls. Breastfeeding modified associations between birth weight and dietary intake, but the direction of modification was mixed.

DISCUSSION

Our findings do not support the hypothesis that LBW or HBW are associated with adverse diet consumption in preschool age U.S. children. Improved understanding of the role of early life development of dietary behavior requires further research on the development of appetitive traits and the role of the family and preschool food environments.

Placental, Matrilineal, and Epigenetic Mechanisms Promoting Environmentally Adaptive Development of the Mammalian Brain

The evolution of intrauterine development, vivipary, and placentation in eutherian mammals has introduced new possibilities and constraints in the regulation of neural plasticity and development which promote neural function that is adaptive to the environment that a developing brain is likely to encounter in the future. A range of evolutionary adaptations associated with placentation transfers disproportionate control of this process to the matriline, a period unique in mammalian development in that there are three matrilineal genomes interacting in the same organism at the same time (maternal, foetal, and postmeiotic oocytes). The interactions between the maternal and developing foetal hypothalamus and placenta can provide a template by which a mother can transmit potentially adaptive information concerning potential future environmental conditions to the developing brain. In conjunction with genomic imprinting, it also provides a template to integrate epigenetic information from both maternal and paternal lineages. Placentation also hands ultimate control of genomic imprinting and intergenerational epigenetic information transfer to the matriline as epigenetic markers undergo erasure and reprogramming in the developing oocyte. These developments, in conjunction with an expanded neocortex, provide a unique evolutionary template by which matrilineal transfer of maternal care, resources, and culture can be used to promote brain development and infant survival.