Flavour Programming during Breast-Feeding

Early life and socio-economic determinants of dietary trajectories in infancy and early childhood - results from the HSHK birth cohort study

BACKGROUND

Early childhood is a period when dietary behaviours are established. This study aimed to examine the longitudinal intake of core and discretionary foods and identify early life and socio-economic factors influencing those intakes.

METHODS

Mother-infant dyads (n = 934) from the Healthy Smiles Healthy Kids study, an ongoing birth cohort study, were interviewed. The information on 'weekly frequency of core and discretionary foods intake' using a food frequency questionnaire was collected at 4 months, 8 months, 1 year, 2 years and 3 years age points. Group-based trajectory modelling analyses were performed to identify diet trajectories for 'core' and 'discretionary' foods respectively. A multinomial logistic regression was performed to identify the maternal and child-related predictors of resulting trajectories.

RESULTS

The intake of core and discretionary foods each showed distinct quadratic (n = 3) trajectories with age. Overall, core foods intake increased rapidly in the first year of life, followed by a decline after age two, whereas discretionary foods intake increased steadily across the five age points. Multiparity (Relative Risk (RR): 0.46, 95%CI: 0.27-0.77), non-English speaking ethnicity of mother (RR: 0.66, 95%CI: 0.47-0.91) and having a single mother (RR: 0.40, 95%CI: 0.18-0.85) were associated with low trajectories of core foods intake whereas older maternal age (RR: 1.05, 95%CI: 1.01-1.08) and longer breastfeeding duration (RR: 1.02, 95%CI: 1.00-1.03) were associated with higher trajectories of core foods intake. Also, multiparity (RR 2.63, 95%CI: 1.47-4.70), low maternal education (RR 3.01, 95%CI: 1.61-5.65), and socio-economic disadvantage (RR 2.69, 95%CI: 1.31-5.55) were associated with high trajectories of discretionary foods intake. Conversely, longer duration of breastfeeding (RR 0.99, 95%CI: 0.97-0.99), and timely introduction of complementary foods (RR 0.30, 95%CI: 0.15-0.61) had a protective effect against high discretionary foods consumption in infancy and early childhood.

CONCLUSION

Children's frequency of discretionary foods intake increases markedly as they transition from infancy to preschool age, and the trajectories of intake established during early childhood are strongly influenced by socio-demographic factors and infant feeding choices. Hence, there is a need for targeted strategies to improve nutrition in early childhood and ultimately prevent the incidence of chronic diseases in children.

Skin-to-skin contact the first hour after birth, underlying implications and clinical practice

AIM

This paper integrates clinical expertise to earlier research about the behaviours of the healthy, alert, full-term infant placed skin-to-skin with the mother during the first hour after birth following a noninstrumental vaginal birth.

METHOD

This state-of-the-art article forms a link within the knowledge-to-action cycle, integrating clinical observations and practice with evidence-based findings to guide clinicians in their work to implement safe uninterrupted skin-to-skin contact the first hours after birth.

RESULTS

Strong scientific research exists about the importance of skin-to-skin in the first hour after birth. This unique time for both mother and infant, individually and in relation to each other, provides vital advantages to short- and long-term health, regulation and bonding. However, worldwide, clinical practice lags. A deeper understanding of the implications for clinical practice, through review of the scientific research, has been integrated with enhanced understanding of the infant's instinctive behaviour and maternal responses while in skin-to-skin contact.

CONCLUSION

The first hour after birth is a sensitive period for both the infant and the mother. Through an enhanced understanding of the newborn infant's instinctive behaviour, practical, evidence-informed suggestions strive to overcome barriers and facilitate enablers of knowledge translation. This time must be protected by evidence-based routines of staff.

Sugar in Infants, Children and Adolescents: A Position Paper of the European Society for Paediatric Gastroenterology, Hepatology and Nutrition Committee on Nutrition

The consumption of sugars, particularly sugar-sweetened beverages (SSBs; beverages or drinks that contain added caloric sweeteners (ie, sucrose, high-fructose corn syrup, fruit juice concentrates), in European children and adolescents exceeds current recommendations. This is of concern because there is no nutritional requirement for free sugars, and infants have an innate preference for sweet taste, which may be modified and reinforced by pre- and postnatal exposures. Sugar-containing beverages/free sugars increase the risk for overweight/obesity and dental caries, can result in poor nutrient supply and reduced dietary diversity, and may be associated with increased risk of type 2 diabetes mellitus, cardiovascular risk, and other health effects. The term "free sugars," includes all monosaccharides/disaccharides added to foods/beverages by the manufacturer/cook/consumer, plus sugars naturally present in honey/syrups/unsweetened fruit juices and fruit juice concentrates. Sugar naturally present in intact fruits and lactose in amounts naturally present in human milk or infant formula, cow/goat milk, and unsweetened milk products is not free sugar. Intake of free sugars should be reduced and minimised with a desirable goal of <5% energy intake in children and adolescents aged ≥2 to 18 years. Intake should probably be even lower in infants and toddlers <2 years. Healthy approaches to beverage and dietary consumption should be established in infancy, with the aim of preventing negative health effects in later childhood and adulthood. Sugar should preferably be consumed as part of a main meal and in a natural form as human milk, milk, unsweetened dairy products, and fresh fruits, rather than as SSBs, fruit juices, smoothies, and/or sweetened milk products. Free sugars in liquid form should be replaced by water or unsweetened milk drinks. National Authorities should adopt policies aimed at reducing the intake of free sugars in infants, children and adolescents. This may include education, improved labelling, restriction of advertising, introducing standards for kindergarten and school meals, and fiscal measures, depending on local circumstances.

A method for the assessment of facial hedonic reactions in newborns

OBJECTIVE

This study describes a quantitative and qualitative methodology to assess hedonic responses to sweet stimulus in healthy newborns.

METHODS

A descriptive, cross-sectional, observational study, with healthy newborns (up to 24h of life), between 37 and 42 gestational weeks, vaginally born and breastfed previously to all tests. The evaluation of the newborns reactions was performed by hedonic facial expression analysis, characterized by facial expressions with rhythmic serial tongue protrusion after neutral or sweet solution intake. Initially, 1mL of water solution was provided to the newborn, followed by a 1-minute recording. Afterwards, the same amount of 25% sucrose solution was provided, performing a second recording. The concordance between researchers was analyzed by the Bland-Altman statistical method.

RESULTS

A total of 100 newborns (n=49 males, n=51 females; mean lifetime=15h 12min±6h 29min) were recorded for neutral and sucrose solution intake, totaling 197 videos (n=3 missing in the water treatment). These videos were double-blind analyzed and the test revealed a 90% concordance between the two trained researchers, in relation to both solutions. The intraclass correlation coefficient was 0.99 for both solutions, with a significant increase in frequency of hedonic expressions evoked by sucrose solution intake.

CONCLUSIONS

These results confirm that the proposed method has an efficient power to detect significant differences between neutral and sucrose stimuli. In conclusion, this evaluation method of hedonic facial reactions in newborns reflects the response to a specific taste.

Psychological and neural contributions to appetite self-regulation

OBJECTIVE

This paper reviews the state of the science on psychological and neural contributions to appetite self-regulation in the context of obesity.

METHODS

Three content areas (neural systems and cognitive functions; parenting and early childhood development; and goal setting and goal striving) served to illustrate different perspectives on the psychological and neural factors that contribute to appetite dysregulation in the context of obesity. Talks were initially delivered at an NIH workshop consisting of experts in these three content areas, and then content areas were further developed through a review of the literature.

RESULTS

Self-regulation of appetite involves a complex interaction between multiple domains, including cognitive, neural, social, and goal-directed behaviors and decision-making. Self-regulation failures can arise from any of these factors, and the resulting implications for obesity should be considered in light of each domain. In some cases, self-regulation is amenable to intervention; however, this does not appear to be universally true, which has implications for both prevention and intervention efforts.

CONCLUSIONS

Appetite regulation is a complex, multifactorial construct. When considering its role in the obesity epidemic, it is advisable to consider its various dimensions together to best inform prevention and treatment efforts.

An exploratory trial of parental advice for increasing vegetable acceptance in infancy

Research suggests that repeatedly offering infants a variety of vegetables during weaning increases vegetable intake and liking. The effect may extend to novel foods. The present study aimed to investigate the impact of advising parents to introduce a variety of single vegetables as first foods on infants' subsequent acceptance of a novel vegetable. Mothers of 4- to 6-month-old infants in the UK, Greece and Portugal were randomised to either an intervention group (n 75), who received guidance on introducing five vegetables (one per d) as first foods repeated over 15 d, or a control group (n 71) who received country-specific ‘usual care’. Infant's consumption (g) and liking (maternal and researcher rated) of an unfamiliar vegetable were assessed 1 month post-intervention. Primary analyses were conducted for the full sample with secondary analyses conducted separately by country. No significant effect of the intervention was found for vegetable intake in the three countries combined. However, sub-group analyses showed that UK intervention infants consumed significantly more novel vegetable than control infants (32·8 (sd 23·6) v. 16·5 (sd 12·1) g; P =0·003). UK mothers and researchers rated infants' vegetable liking higher in the intervention than in control condition. In Portugal and Greece, there was no significant intervention effect on infants' vegetable intake or liking. The differing outcome between countries possibly reflects cultural variations in existing weaning practices. However, the UK results suggest in countries where vegetables are not common first foods, advice on introducing a variety of vegetables early in weaning may be beneficial for increasing vegetable acceptance.

Perinatal administration of a bitter tastant influences gene expression in chicken palate and duodenum

Bitter taste receptors (Tas2rs) and downstream effectors are responsible for mediating bitterness perception and regulation of food choice in mammals. Using RT-PCR, we demonstrated the expression of three Tas2rs and taste signal transduction molecules, α-gustducin, PLCβ2, and TRPM5, in the palate, tongue, and gastrointestinal tract sections in chicken. The bitter tastant quinine activates all three chicken Tas2rs in vitro as shown using calcium-imaging assays of transfected cells. Administration of quinine postnatally or perinatally (both pre- and posthatch) to chickens increased the expression of Tas2r genes in the palate by 6.45-fold (ggTas2r1 postnatal treatment), 4.86-fold (ggTas2r1 perinatal treatment), and 4.48-fold (ggTas2r7 postnatal treatment) compared to the genes' expression in the naı̈ve group respectively, and affected taste related gene expression in the duodenum. Whereas no-choice intake of quinine solution was not significantly lower than that of water in naı̈ve chicks, the treatment groups postnatal, prenatal, and perinatal showed significantly lower intake of quinine by 56.1, 47.7, and 50.2%, respectively, suggesting a possible trend toward sensitization. These results open new venues toward unraveling the formative stages shaping food intake and nutrition in chicken.

Learning to eat: birth to age 2 y

During the first 2 y of life, development is rapid and includes dramatic changes in eating behavior. Individual patterns of food preferences and eating behaviors emerge and differ depending on the foods offered and on the contexts of feeding during this early period of dietary transition. In this review, we discuss evidence on ways in which early learning influences food preferences and eating behavior, which, in turn, shape differences in dietary patterns, growth, and health. Although the evidence reviewed indicates that this early period of transition provides opportunities to influence children's developing intake patterns, there is no consistent, evidence-based guidance for caregivers who are feeding infants and toddlers; the current Dietary Guidelines are intended to apply to Americans over the age of 2 y. At present, the evidence base with regard to how and what children learn about food and eating behavior during these first years is limited. Before developing guidance for parents and caregivers, more scholarship and research is necessary to understand how infants and toddlers develop the food preferences and self-regulatory processes necessary to promote healthy growth, particularly in today's environment. By the time they reach 2 y of age, children have essentially completed the transition to "table foods" and are consuming diets similar to those of other family members. This article discusses parenting and feeding approaches that may facilitate or impede the development of self-regulation of intake and the acceptance of a variety of foods and flavors necessary for a healthy diet. We review the limited evidence on how traditional feeding practices, familiarization, associative learning, and observational learning affect the development of eating behavior in the context of the current food environment. Areas for future research that could inform the development of anticipatory guidance for parents and caregivers responsible for the care and feeding of young children are identified.

Dietary patterns of Australian children aged 14 and 24 months, and associations with socio-demographic factors and adiposity

BACKGROUND/OBJECTIVES

Previous research has shown, in predominantly European populations, that dietary patterns are evident early in life. However, little is known about early-life dietary patterns in Australian children. We aimed to describe dietary patterns of Australian toddlers and their associations with socio-demographic characteristics and adiposity.

SUBJECTS/METHODS

Principal component analysis was applied to 3 days (1 × 24-h recall and 2 × 24-h record) data of 14 (n=552)- and 24 (n=493)-month-old children from two Australian studies, NOURISH and South Australian Infant Dietary Intake (SAIDI). Associations with dietary patterns were investigated using regression analyses.

RESULTS

Two patterns were identified at both ages. At 14 months, the first pattern was characterised by fruit, grains, vegetables, cheese and nuts/seeds ('14-month core foods') and the second pattern was characterised by white bread, milk, spreads, juice and ice-cream ('basic combination'). Similarly, at 24 months the '24-month core foods' pattern included fruit, vegetables, dairy, nuts/seeds, meat and water, whereas the 'non-core foods' included white bread, spreads, sweetened beverages, snacks, chocolate and processed meat. Lower maternal age and earlier breastfeeding cessation were associated with higher 'basic combination' and 'non-core foods' pattern scores, whereas earlier and later solid introduction were associated with higher 'basic combination' and '24-month core foods' pattern scores, respectively. Patterns were not associated with body mass index (BMI) z-score.

CONCLUSIONS

Dietary patterns reflecting core and non-core food intake are identifiable in Australian toddlers. These findings support the need to intervene early with parents to promote healthy eating in children and can inform future investigations on the effects of early diet on long-term health.

Biocultural considerations of food cravings and aversions: an introduction

Food is fundamental to our existence as humans, but assertions about the kinds of foods that are appealing or repulsive vary widely. This thematic issue deals with assessments of food as desirable, or not, in order to understand the complex reasons why some foods are strongly craved while others are avoided. To do this, the five articles in this issue situate food cravings and aversions bioculturally, in the contexts of our history as a species, in the landscape of cultural heritage, and in the individual life course. By exploring both the biological and cultural mechanisms that shape food preferences, we reveal the complex and important underpinnings of the critical endeavor of food selection.

Evolution and development of dual ingestion systems in mammals: notes on a new thesis and its clinical implications

Traditionally, the development of oral feeding is viewed as a continuous, unitary process in which reflex-dominated sucking behavior gives rise to a more varied and volitional feeding behavior. In contrast, we consider the thesis that the infant develops two separable ingestive systems, one for suckling and one for feeding. First, we apply an evolutionary perspective, recognizing that suckling-feeding is a universal, mammalian developmental sequence. We find that in mammalian evolution, feeding systems in offspring were established prior to the evolution of lactation, and therefore suckling is a separable feature that was added to feeding. We next review an experimental literature that characterizes suckling and feeding as separable in terms of their topography, sensory controls, physiological controls, neural substrates, and experience-based development. Together, these considerations constitute a view of “dual ingestive systems.” The thesis, then, is that suckling is not a simple precursor of feeding but is a complete behavior that emerges, forms, and then undergoes a dissolution that overlaps with the emergence of independent feeding. This thesis guides us to focus differently on the challenges of properly managing and facilitating oral ingestion in infants, especially those born preterm, prior to the developmental onset of suckling.

Breast-feeding duration: influence on taste acceptance over the first year of life

Early feeding experiences, e.g. related to milk feeding, can affect later food and taste preferences. However, consequences of breast-feeding on taste acceptance are under-investigated. The objective of the present study was to examine the impact of exclusive breast-feeding duration (DEB) on taste acceptance at 6 and 12 months in the same infants (n122). Mothers recorded the DEB. Acceptance of solutions of each of the five basic tastes relative to water was evaluated in the laboratory at 6 and 12 months by the ingestion ratio (IR). Kendall correlations were calculated between the DEB and the IR. Only 16 % completed at least 6 months of exclusive breast-feeding; 79 % had begun complementary feeding by 6 months. At 6 months, infants preferred sweet, salty and umami solutions over water and were indifferent to sour and bitter solutions. The longer an infant was breast-fed, the more s/he accepted the umami solution at 6 months. At 12 months, infants preferred sweet and salty solutions over water and were indifferent to sour, bitter and umami solutions. The relationship between the DEB and acceptance of the umami solution was not observed at 12 months. No relationship was observed between the DEB and sweet, salty, sour and bitter taste acceptance at 6 or 12 months. The association between the DEB and umami taste acceptance at 6 months may relate to the higher glutamate content of human milk compared with formula milk. Beyond the acknowledged metabolic benefits of breast-feeding, this suggests that prolonged breast-feeding could also be associated with an impact on sensory preference at the beginning of complementary feeding.

Maternal "junk-food" feeding of rat dams alters food choices and development of the mesolimbic reward pathway in the offspring

Individuals exposed to high-fat, high-sugar diets before birth have an increased risk of obesity in later life. Recent studies have shown that these offspring exhibit increased preference for fat, leading to suggestions that perinatal exposure to high-fat, high-sugar foods results in permanent changes within the central reward system that increase the subsequent drive to overconsume palatable foods. The present study has determined the effect of a maternal "junk-food" diet on the expression of key components of the mesolimbic reward pathway in the offspring of rat dams at 6 wk and 3 mo of age. We show that offspring of junk-food-fed (JF) dams exhibit higher fat intake from weaning until at least 3 mo of age (males: 16 ± 0.6 vs. 11 ± 0.8 g/kg/d; females: 19 ± 1.3 vs. 13 ± 0.4 g/kg/d; P<0.01). mRNA expression of μ-opioid receptor (Mu) was 1.6-fold higher (P<0.01) and dopamine active transporter (DAT) was 2-fold lower (P<0.05) in JF offspring at 6 wk of age. By 3 mo, these differences were reversed, and Mu mRNA expression was 2.8-fold lower (P<0.01) and DAT mRNA expression was 1.9-fold higher (P<0.01) in the JF offspring. These findings suggest that perinatal exposure to high-fat, high-sugar diets results in altered development of the central reward system, resulting in increased fat intake and altered response of the reward system to excessive junk-food intake in postnatal life.

[To which tastes are infants exposed during the first year of life?]

Food consumption in young children is guided by their food preferences, which are partly determined by their attraction to the different tastes (sweet, salty, sour, bitter, and umami tastes). Early food experiences might modulate this attraction. Yet, no study has previously described the tastes of infant foods during the first year of life. This is the objective of the present study. The diet of 76 infants was recorded by their parents 1 week per month during the first year of life. This record provided an inventory of 2902 foods a priori different from a sensory point of view. The taste intensity of these foods was estimated. For each infant, each month, and each taste, a variable of exposure to the taste was calculated. Foods consumed by infants from 1 to 12 months of age generally had low or relatively moderate taste intensity. During the milk-feeding period, infants were mainly exposed to sweet taste; this exposure increased during the first year. Beginning with weaning, the exposure to sour taste rose sharply without becoming as high as the exposure to sweet taste, the exposures to salty and umami tastes rose modestly, and the exposure to bitter taste rose slightly, then stagnated. Consequently, the proportion of bitter taste was reduced to approximately half the other tastes between the age of 7 and 12 months. Taking these observations into account would be helpful in establishing feeding recommendations for the pediatric population.

The effect of taste familiarity on intake and taste reactivity in infant rats

With infant rats, unlike with adults, increased intake of a taste after mere exposure to this stimulus is not consistently found; this has sometimes been interpreted as a failure by the immature subject to recognize tastes as familiar. We studied the effect of preexposure to a tastant, measuring taste reactivity and intake in 14-day-old rats. Familiarity increased hedonic response to sucrose, but also increased aversive response to quinine and ethanol. With the sucrose-quinine compound, familiarity increased both the hedonic and the aversive reaction to the stimulus. In no case was a differential reactivity to water observed. Significant increased intake after familiarization was only found with quinine or the sucrose-quinine compound. Results indicate that in infant rats, and with the present parameters, taste familiarity enhances responsiveness to these stimuli, an effect not always accompanied by detectable changes in intake.