NNIW 95 - Building Future Health and Well-Being of Thriving Toddlers and Young Children

Motor skills are important for development. Everything infants do involves motor skills –
postural, locomotor, and manual actions; exploratory actions; social interactions; and actions with artifacts. Put another way, all behavior is motor behavior, and thus motor skill acquisition is synonymous with behavioral development. Age norms for basic motor skills provide useful diagnostics for “typical” development, but cultural differences in child-rearing practices influence skill onset ages. Whenever they emerge, motor skills lay the foundation for development by opening up new opportunities for learning. Postural control brings new
parts of the environment into view and into reach; locomotion makes the larger world accessible; manual skills promote new forms of interactions with objects; and motor skills involving every part of the body enhance opportunities for social interaction. Thus, motor skills can instigate a cascade of developments in domains far afield from motor behavior – perception and cognition, language and communication, emotional expression and regulation, physical growth and health, and so on. Finally, motor skill acquisition makes behavior increasingly functional and flexible. Infants learn to tailor behavior to variations in their body and environment and to discover or construct new means to achieve their goals.

Today, children are less active than previous generations leading to an increased prevalence of morbidity associated with physical inactivity. Globally, full-day preschool is rapidly becoming the norm. Thus, the amount of time that a child spends outside the home is an opportunity for schools and teachers to educate children about the importance of participating in physical activity and making healthy eating choices. One approach to comprehensively offer opportunities for physical activity and healthy eating is called Whole School, Whole Community, Whole Child, which intertwines academic success and promotion of healthy behaviors. Particularly for adolescent children, multicomponent approaches that include both school and family or community involvement have the most significant potential to make meaningful differences in the rate of physical activity participation. For young children, teacher training, resources, and equipment are needed to achieve equity across programs and schools, because these are predictors of physical activity participation. Further, school policies, administrative support, modeling by teachers, and the use of cues and incentives can have a positive effect. The purpose of this paper is to describe the benefits of contemporary, evidence- based models for providing opportunities for health behaviors in school from early childhood to adolescence. 

Greater abilities for executive control in childhood have long-term benefits for academic and vocational success. Therefore, lifestyle approaches with the potential to support executive control in childhood stand to have long-term implications not only for physical but also for cognitive health. Nutrition plays a fundamental role in brain structure and function. While a considerable amount of literature demonstrates the detrimental effects of deficiencies in essential nutrients, comparatively little is known is about the role of overall diet quality in promoting executive control among children without diagnosed nutrient deficiencies. Emerging evidence provides preliminary support for the importance of key nutrients (e.g., water, dietary fiber, carotenoids, and choline) that contribute to diet quality. This article represents a brief narrative review that aims to highlight the importance of habitual diet quality for executive control in childhood. Additional research is needed to continue developing the evidence base for diet patterns and nutrients that preferentially support executive control during childhood. This is an important goal given that nutritional recommendations for children’s cognitive function are absent from the US dietary guidelines, making the endeavor to develop the evidence base for diet patterns and nutrients that preferentially support executive control during childhood all the more important. 

Physical activity (PA) can improve physical, mental, cognitive, and brain health throughout
the lifespan. During preadolescent childhood, the benefits of PA for cognitive health have
been widely studied, with evidence indicating enhanced executive control, improved academic performance, and adaptation in underlying brain structure and function. Across
school age children, the predominant literature has focused on preadolescent children, with
a comparatively smaller body of evidence in adolescent children. Yet, preliminary findings
suggest improvements in verbal, numeric, and reasoning abilities as well as academic
achievements. Further, benefits of PA are also rarely examined in preschool children. Consequently, lack of standardization across studies has led to various approaches in the measurement of PA and fitness. However, since implementing tools that objectively quantify
active play, PA has been related to better executive function, language acquisition, and academic achievement. Despite evidence that PA promotes cognitive and brain health during development, a growing number of schools have minimized PA opportunities across the school day. The minimization of PA along with several other factors, including lack of active commuting to school, nutrition transition, and availability of electronic devices, for example, has reduced children’s physical and mental health. Accordingly, today’s children have become increasingly inactive, which affects public health and contributes to educational concerns. By dedicating time to active play, sports, physical education, and other forms of PA, children are best positioned to thrive in both the physical and cognitive domains. 

Over the course of evolution, Mother Nature preserved the ability of humans to make every
sugar they need for metabolic functions. Glucose is the almost exclusive fuel preferred by
the human brain. Human infants are born with sweet taste receptors, sugars are a significant energy source in human milk, and mammals have a direct gut-to-brain sugar-sensing system that enhances development of a preference for sugars. If sugars are as toxic as many postulate, what species advantage was conferred by this evolutionary progression? Observational studies have reported that sugar consumption is associated with various adverse health risks. However, observational studies can never prove causality, dietary intake records are known to be highly problematic, and the huge number of correlation interdependencies among environmental “exposome” variables makes it impossible to attribute causality to individual dietary components. Additionally, these studies overall have been graded as low quality, and many reported the small effect sizes are likely within the propagated methodological “noise.” With several exceptions, data from randomized controlled trials that ensured isocaloric energy intakes have failed to confirm the causal implications of the observational data. Likewise, the comprehensive UK Scientific Committee on Nutrition Report on Carbohydrates and Health also failed to confirm the vast majority of widely postulated detrimental effects of sugar consumption per se. Current data on intakes of sugar-sweetened beverages and on the risks associated with high intakes of dietary fructose remain under debate. 

Children reportedly consume a variety of adequate vegetables during the introduction of
complementary foods, and breastfeeding helps to facilitate child food acceptance. However, dietary intake of vegetables is reported to fall when children begin to eat foods of the family table. In laboratory settings, repeated exposure is effective in promoting children’s acceptance and consumption of novel foods. We have recently explored mother and child early experiences (from infancy to toddlerhood) with offering hard-to-like foods. Our findings suggest a “sweet spot” for food introduction and acceptance during the early complementary feeding period (6–12 months) with increasing variability in acceptance and negative child behaviors occurring during toddlerhood. When queried, most mothers are familiar with repeated exposure concepts, but their persistence in continuing to offer disliked foods differs. Some report they will “never give up” – a stance linked to health beliefs and that children should “eat what we eat.” Others seem more influenced by children’s resistance and food dislikes, and the amounts their child eat. The majority believe that children’s tastes change and that their child will accept rejected foods later. These mothers may reoffer a rejected food after “a break.” Opportunities exist to translate repeated exposure paradigms to practical methods mothers can successfully adopt in the home. 

To understand the development of children’s flavor preferences, it is important to consider
the context of the feeding environment. Although children are predisposed to prefer sweet tasting foods and beverages and to avoid bitter-tasting foods such as dark-green vegetables, parents can play a central role in shifting these innate food acceptance patterns throughout development. Beginning before birth, the fetus detects the continually changing flavor profile of amniotic fluid, which reflects the mother’s diet. After birth, if mothers choose to breastfeed, these sensory experiences continue. Through this process of familiarization, women who maintain a healthy diet throughout pregnancy and lactation prepare their infants to like healthful foods. Upon the introduction of solid foods, repeated exposure to a variety of healthful foods promotes acceptance for these foods and for novel foods. In addition to providing sensory exposures to a range of healthful foods, parents can shape children’s flavor preferences by modeling healthy eating behaviors and by creating supportive feeding environments. The degree to which parents engage in these practices is influenced by demographic and societal characteristics. Considering the context in which children and families live will encourage the development of evidence-based strategies that more effectively support children’s healthy eating habits. 

Establishing dietary recommendations for micronutrients in young children is difficult. Techniques used to evaluate nutrient intake and bioavailability are hard to apply in this age group. Additionally, large variations in growth rates, dietary patterns, and nutrient losses in early childhood make determinations of dietary requirements difficult. Most recent studies have utilized stable isotopes to determine mineral absorption for iron, zinc, calcium, and magnesium. Vitamin D requirements have been established based on the dietary intake required to maintain a presumed adequate serum 25-hydroxyvitamin D concentration. Comparisons of nutrient requirements established using factorial methods involving absorption determinations and usual population intake are important to identify nutrients of concern related to deficient or excess intakes. Generally, in the USA, the intakes of calcium and magnesium are adequate to meet requirements in most toddler diets which include a milk source or a mineral-fortified milk alternative. Zinc and iron intakes can be below requirements in a substantial proportion of toddlers throughout the world, especially those with minimal meat consumption. Dietary vitamin D is generally below dietary recommendations, but clearly deficient serum 25-hydroxyvitamin D concentrations are less common, and the global role for routine vitamin D supplementation or fortification of the diet remains uncertain.

Child care has broad reach to young children. Yet, not all child care settings have nutrition
standards for what and how foods and beverages should be served to infants as they transition to toddlerhood. The purpose of this paper is to describe the development of nutrition recommendations to guide feeding young children in licensed child care settings in the USA, a process that could be adapted in other countries. Nutrition standards were designed by nutrition and child care experts to address what and how to feed young children, also including the transition from infants to toddlers. Nutrition standards are important for health and can be feasibly implemented in child care settings. Feasibility considerations focused on family child care homes, which typically have fewer resources than child care centers or preschools. Infant standards include recommendations for vegetables, fruits, proteins, grains, and breast milk and other beverages. Also included are recommendations for supporting breastfeeding, introducing complementary foods, and promoting self-regulation in response to hunger and satiety. Toddler standards are expanded to address the frequency as well as types of food groups, and recommendations on beverages, sugar, sodium, and fat. Feeding practice recommendations include meal and snack frequency and style, as well as the promotion of self-regulation among older children. 

The rapid rise in obesity in toddlers and young children (aged 0–5 years) is a major concern
for public health globally. Understanding risk factors for obesity in the early years is therefore
fundamental to help guide parents, educators, and health care professionals caring for
young children and to develop preventative strategies. Most research has focused on biological
risk factors, which can be broadly categorized as genetic predisposition, poor diet
(and the behaviors that influence excessive food intake), insufficient physical activity, and
the role of developmental factors in early life that influence long-term health. The latter includes
establishment of dietary habits and dietary patterns in young (preschool) children
and the effect of a high protein intake on the increasing risk of later obesity. Other risk factors
particularly relevant to young children include inadequate sleep, high consumption of
sugar-sweetened drinks, and large food portions. Understanding the causes of obesity in
preschool children is particularly important in view of long-term detrimental consequences
of obesity in this age group on the risk of obesity and cardiometabolic disease in adults. The
present chapter reviews causes of obesity in preschool children and its consequences for
long-term health, focusing particularly on modifiable nutritional risk factors.

The great majority of attention on growth faltering concentrates on the first “1,000 days”
with a much lesser focus on toddlers and young preschoolers. The rationale for this is understandable since the first 1,000 days cover the period of most rapid growth and changes in body composition, the period of breastfeeding, and the complex transition from breastfeeding and weaning to complementary feeds, and then moving to the family/adult diet. There has also been a strong perception that, once a child has become stunted or wasted in the first 2 years of life, there is little hope of recovery, an assumption we address below. This paper will describe the timing of the development of stunting and wasting, addressing 3 critical periods: intergenerational, in utero, and early postnatal life. The question of whether toddlers and young preschoolers can recover from stunting and wasting will also be addressed; our own studies suggest that a degree of recovery is certainly possible. The hormonal mechanisms regulating early growth will be examined. Finally, the issue of whether toddlers and young preschoolers should have special foods and diets will also be discussed.

Toddlers and young children need an adequate and diverse diet to provide all of the nutrients required for optimal growth and development. Unfortunately, inadequate intake of
vitamins and minerals is still identified by the World Health Organization (WHO) as a major
public health threat for young children. Organizations like the WHO and the World Bank focus primarily on iron, zinc, vitamin A, and iodine for children ≤5 years of age in low-income countries. In addition to the data from these organizations, individual-level food consumption surveys are needed to provide a fuller picture of food and nutrient intakes. Where studies are available, intakes of dietary fiber and vitamin D are generally below recommendations for toddlers and young children. Other nutrient gaps differ by country and are related to food availability and local dietary habits. For example, young children in the US regularly consume dairy products, and < 10% fall below recommendations for calcium intake compared to 2- to 4-year-old toddlers in the Philippines where dairy food consumption is low, and 66–84% fall below calcium recommendations. Dietary intake studies can help to identify the foods and beverages most relevant to alleviate nutrient gaps and improve dietary intakes of toddlers and young children around the world. 

Toddlerhood, the period from 12 to 36 months, represents striking changes in children’s
development. Along with mastery of skills such as walking, talking, self-feeding, sleeping
through the night, and bowel and bladder control, toddlers strive for autonomy as they learn
to regulate their emotions. Toddlers’ increasing autonomy impacts feeding behavior and
may increase or restrict their food exposures. Baby-led weaning, allowing infants to participate in the family meal by selecting food and feeding themselves, exposes children to the family diet. Food neophobia, a normal developmental phase whereby children reject novel foods, may limit children’s exposure to high-quality foods. Food preferences formed during toddler and preschool years often persist into adulthood, making toddlerhood an ideal time to help children build healthy habits. Toddlerhood can be both joyful and challenging as children acquire new skills and assert their autonomy. Effective parenting practices include providing age-appropriate structure and opportunities for toddlers, reading toddler’s signals, and responding promptly, appropriately, and with nurturance. Responsive parenting ensures that toddlers receive the guidance and nurturant care needed to develop healthy feeding behavior and emotional well-being.