Complementary feeding and developmental milestones: a systematic review

Dietary Patterns and Health: Insights From NESR Systematic Reviews to Inform the Dietary Guidelines for Americans

This perspective article shares unique insights from the extensive experience of the US Department of Agriculture Nutrition Evidence Systematic Review branch in conducting systematic reviews on dietary patterns and health outcomes to inform the Dietary Guidelines for Americans. Methodological approaches for reviewing dietary patterns research are described, including approaches to operationalizing definitions and analyzing labeled dietary patterns. The review also describes techniques for synthesizing dietary patterns research across life stages in systematic reviews that inform food-based, federal dietary guidance. Current research activities and recommendations for how to improve or address gaps in dietary patterns research in the future are also discussed.

An equitable, community-engaged translational framework for science in human lactation and infant feeding-a report from "Breastmilk Ecology: Genesis of Infant Nutrition (BEGIN)" Working Group 5

Human milk is the ideal source of nutrition for most infants, but significant gaps remain in our understanding of human milk biology. As part of addressing these gaps, the Breastmilk Ecology: Genesis of Infant Nutrition (BEGIN) Project Working Groups 1-4 interrogated the state of knowledge regarding the infant-human milk-lactating parent triad. However, to optimize the impact of newly generated knowledge across all stages of human milk research, the need remained for a translational research framework specific to the field. Thus, with inspiration from the simplified environmental sciences framework of Kaufman and Curl, Working Group 5 of the BEGIN Project developed a translational framework for science in human lactation and infant feeding, which includes 5 nonlinear, interconnected translational stages, T1: Discovery; T2: Human health implications; T3: Clinical and public health implications; T4: Implementation; and T5: Impact. The framework is accompanied by 6 overarching principles: 1) Research spans the translational continuum in a nonlinear, nonhierarchical manner; 2) Projects engage interdisciplinary teams in continuous collaboration and cross talk; 3) Priorities and study designs incorporate a diverse range of contextual factors; 4) Research teams include community stakeholders from the outset through purposeful, ethical, and equitable engagement; 5) Research designs and conceptual models incorporate respectful care for the birthing parent and address implications for the lactating parent; 6) Research implications for real-world settings account for contextual factors surrounding the feeding of human milk, including exclusivity and mode of feeding. To demonstrate application of the presented translational research framework and its overarching principles, 6 case studies are included, each illustrating research gaps across all stages of the framework. Applying a translational framework approach to addressing gaps in the science of human milk feeding is an important step toward the aligned goals of optimizing infant feeding across diverse contexts as well as optimizing health for all.

Complementary and Allergenic Food Introduction in Infants: An Umbrella Review

BACKGROUND

Multiple systematic reviews examine the introduction of foods in relation to individual health outcomes, but the balance of harms and benefits has not been overviewed systematically.

OBJECTIVES

We aimed to perform an overview of systematic reviews on age of introduction of complementary and allergenic foods to the infant diet and long and short-term health outcomes.

DATA SOURCES

We searched Medline, Embase, Cochrane, and PubMed (July 25, 2022).

STUDY SELECTION

Included systematic reviews examining the introduction of complementary or allergenic foods before age 1. Outcomes included allergic, autoimmune, and inflammatory diseases, neurodevelopment, nutrition, and weight.

DATA EXTRACTION

Extraction and quality assessment were performed in duplicate (A Measurement Tool to Assess Systematic Reviews) and strength of evidence was assessed.

RESULTS

We screened 4015 articles and included 32 systematic reviews. There was moderate evidence that peanut and egg should be introduced from 4 to 11 months to prevent food allergy (6 of 10 reviews). Complementary food introduction was not associated with food allergy. Moderate certainty evidence suggested age of complementary food introduction was not associated with eczema. Age at introduction of gluten was not associated with celiac disease (high certainty evidence; 3 of 4 reviews). Low certainty evidence indicated that introducing solids before 4 months may increase the risk of childhood obesity, but not growth. There was insufficient evidence regarding an association between any food introduction and bone health, gastrointestinal diseases, autoimmune disorders, asthma, or allergic rhinitis.

LIMITATIONS

Gray literature was not included.

CONCLUSIONS

Current evidence supports introducing complementary foods around 6 months and allergenic foods before 11 months.

Dietary and Complementary Feeding Practices of US Infants, 6 to 12 Months: A Narrative Review of the Federal Nutrition Monitoring Data

Complementary foods and beverages (CFBs) are key components of an infant's diet in the second 6 months of life. This article summarizes nutrition and feeding practices examined by the 2020 Dietary Guidelines Advisory Committees during the CFB life stage. Breastfeeding initiation is high (84%), but exclusive breastfeeding at 6 months (26%) is below the Healthy People 2030 goal (42%). Most infants (51%) are introduced to CFBs sometime before 6 months. The primary mode of feeding (ie, human milk fed [HMF]; infant formula or mixed formula and human milk fed [FMF]) at the initiation of CFBs is associated with the timing of introduction and types of CFBs reported. FMF infants (42%) are more likely to be introduced to CFBs before 4 months compared with HMF infants (19%). Different dietary patterns, such as higher prevalence of consumption and mean amounts, were observed, including fruit, grains, dairy, proteins, and solid fats. Compared with HMF infants of the same age, FMF infants consume more total energy (845 vs 631 kcal) and protein (22 vs 12 g) from all sources, and more energy (345 vs 204 kcal) and protein (11 vs 6 g) from CFBs alone. HMF infants have a higher prevalence of risk of inadequate intakes of iron (77% vs 7%), zinc (54% vs <3%), and protein (27% vs <3%). FMF infants are more likely to have an early introduction (<12 months) to fruit juice (45% vs 20%) and cow's milk (36% vs 24%). Registered dietitian nutritionists and nutritional professionals should consider tailoring their advice to caregivers on dietary and complementary feeding practices, taking into account the primary mode of milk feeding during this life stage to support infants' nutrient adequacy. National studies that address the limitations of this analysis, including small sample sizes and imputed breast milk volume, could refine findings from this analysis.

Methodological Aspects of Diet Quality Indicators in Childhood: A Mapping Review

Diet quality indicators (DQIns) are tools that aim to assess an individual's overall diet quality. Previous reviews focused mainly on health-related outcomes but did not provide detailed information about components, assessment variables, or important methodological issues for the development and application of DQIns in the pediatric age. The current mapping review aims to provide comprehensive guidance regarding DQIns developed through a priori methodology in children aged ≤14 y that have been applied worldwide. A mapping review was conducted, whereby 1665 original articles describing the development, modifications, and updates of DQIns, published up to June 26, 2020, in English and Spanish, were retrieved. A total of 139 articles were identified and classified into 13 subgroups. There were 10 overall DQIns: Healthy Eating Indexes (n = 25), Dietary Diversity Scores (n = 20), Diet Quality Indexes (n = 16), Food Variety Scores (n = 11), Healthy and Unhealthy Scores (n = 11), Feeding and Eating Indexes (n = 10), Diet Quality Scores (n = 5), Nutritional Adequacy and Micronutrients Indexes (n = 5), Dietary Guidelines Indexes (n = 5), and Other Healthy Diet Indexes (n = 13). Three additional subgroups of dietary and lifestyle indicators found were Mediterranean Diet Indexes (n = 10), Diet-Lifestyle Indexes (n = 5), and Breakfast Quality Indexes (n = 3). This compilation of DQIns will help researchers select the most appropriate tool for future epidemiological studies by considering a careful selection of information about the assessment components, scoring methods, and key methodological issues. The main limitations of this review are that, due to its nature, a risk-of-bias assessment was not performed and the article screening was completed in 2 databases (PubMed/MEDLINE and Scopus). More research is needed to identify health-related outcomes associated with DQIns in the pediatric population, using clearer and more standardized methodological criteria.

Infant feeding in diverse families; the impact of ethnicity and migration on feeding practices

OBJECTIVE

To investigate differences in infant feeding practices and styles by maternal migration status.

DESIGN

Prospective cohort study.

SETTING

Maternity unit of a large hospital in Northern England PARTICIPANTS: Women recruited to the Born in Bradford longitudinal cohort study MEASUREMENTS: Breastfeeding initiation; breastfeeding at six months; breastfeeding at twelve months; timing of introduction of complementary feeding; maternal feeding style at twelve months.

FINDINGS

Migrant women were more likely to initiate breastfeeding and continue breastfeeding for longer compared to native women. Native women also introduced complementary feeding earlier than migrant women. There was evidence of feeding practices among second= generation migrants becoming increasingly more aligned with those of native women, with lower breastfeeding rates and earlier introduction of complementary feeding compared to first-generation migrants. Migrant women were more likely to adopt a 'Demanding' feeding style, with the strongest associations seen in first-generation migrants.

KEY CONCLUSIONS

Migration status is an important factor to consider in reference to infant feeding practices. This is particularly important in considering intergenerational changes in families with migration backgrounds and the potential of culture to impact on family practices.

IMPLICATIONS FOR PRACTICE

Interventions to maintain cultural norms around infant feeding in families with migration backgrounds would be beneficial, due to the observed higher rates of breastfeeding in first-generation migrants. Targeted interventions to improve breastfeeding in white British native women should consider the role that culture can play in encouraging positive health behaviours.

Timing of Introduction of Complementary Foods and Beverages to Infants of Low-Income Women

Background: Although rates of complementary food and beverage (CFB) consumption among infants under 4 to 6 months of age have been declining, they remain well above the American Academy of Pediatrics (AAPs) recommendations. It is unclear if women with low income in the United States are more likely than other women to introduce CFBs early. We examined timing of introduction of CFBs to infants of mothers with low income to further illuminate infant feeding practices in this potentially vulnerable population. Materials and Methods: We analyzed infant feeding data collected prospectively from 443 mother-infant dyads. Data were obtained by interview at 1, 3, and 6 months postpartum. We used Kaplan-Meier curves to show time to introduction of CFBs overall and by type of CFB, and log-rank tests to compare timing by demographic and clinical characteristics. Results: Participants were mostly non-Hispanic black or white, with a high school education or less. By month 3, 48% of infants were fed at least one CFB, increasing to over 83% by month 5. Women who did not work outside the home introduced CFBs significantly earlier than those who worked, as did women who smoked compared with those who did not. Timing did not differ by other participant characteristics. Conclusions: Introduction of CFBs before 4-6 months was common. Clinical guidance and intervention programs should support mothers toward the goal of improving infant diets in this at-risk population.

Complementary feeding of infants and young children 6 to 23 months of age

Complementary feeding, when foods are introduced to complement a milk-based diet, generally occurs between 6 and 23 months of age. It is a critical period for both physical and cognitive development. During this period, the growth rate of the brain is one of the fastest during the life span and, consequently, the timing, dose, and duration of exposure to specific nutrients can result in both positive and negative effects. Complementary feeding is more than ensuring an adequate intake of nutrients; it also is about avoiding excess intakes of calories, salt, sugars, and unhealthy fats. Meals are cultural and social events where young children observe, imitate, learn about foods to like or dislike, and form lifelong eating habits and practices. Meals are also when a child learns to touch foods and connect food tastes to how foods look and feel. Ideally, complementary feeding is responsive and promotes child autonomy, but it can also be used to manage behavior problems or overly indulge a child, resulting in long-term consequences for nutrition and health. Therefore, in addition to what a child is fed, attention to how a child is fed is also important. In this review, 12 topics relevant for updating global guidance on complementary feeding were identified: age of introduction of complementary foods; continued breastfeeding; responsive feeding; safe preparation and storage of complementary foods; food textures, flavors, and acceptance; energy and meal and snack frequency; fats, protein, and carbohydrates; dietary diversity; milks other than breast milk; fluid needs; unhealthy foods and beverages; and use of vitamin and mineral supplements or supplementary foods.

Complementary Feeding: Pitfalls for Health Outcomes

The term complementary feeding is defined as the period in which a progressive reduction of breastfeeding or infant-formula feeding takes place, while the infant is gradually introduced to solid foods. It is a crucial time in the infant's life, not only because of the rapid changes in nutritional requirements and the consequent impact on infant growth and development, but also for a generation of lifelong flavor preferences and dietary habits that will influence mid and long-term health. There is an increasing body of evidence addressing the pivotal role of nutrition, especially during the early stages of life, and its link to the onset of chronic non-communicable diseases, such as obesity, hypertension, diabetes, and allergic diseases. It is clear that the way in which a child is introduced to complementary foods may have effects on the individual's entire life. The aim of this review is to discuss the effects of complementary feeding timing, composition, and mode on mid and long-term health outcomes, in the light of the current evidence. Furthermore, we suggest practical tips for a healthy approach to complementary feeding, aiming at a healthy future, and highlight gaps to be filled.

Nutrition in developmental age: few rules to stay healthy

The first 1000 days of life represent a critical window for infants' and children's development. Overweight and insulin resistance, at the basis of non-communicable diseases (NCDs), are linked to various risk factors that begin in childhood, including children's diet. Italian data on infants' and children's dietary habits show higher intake of proteins, simple sugars, unhealthy fats and salt than recommended, while the iron intake is below requirement. We reviewed current literature analyzing observational studies, meta-analysis, systematic review and randomized clinical trials of the last 10 years (from 2009) on nutrition in developmental age, providing some few rules to abide by. Exclusive breastfeeding is recommended by World Health Organization for the first 6 months of life and it should be continued alongside the complementary feeding period until 12 months, or even afterward. Complementary feeding should not be started before the 17th week of age with energetically adequate foods, paying attention to limit protein intake and favoring iron-rich foods. Intake of simple sugars should be limited or avoided at all; it has been demonstrated that substituting sugar-sweetened beverages with water decreases body fatness development in adolescence. Quality of the ingested fats is more important than their quantity: polyunsaturated fatty acids should be preferred. Sodium intake should be limited in the first 24 months of life, as first prevention measure of arterial hypertension later in adulthood. Healthy eating habits are the first important step toward the prevention of NCDs.

Association of infant and young child feeding practices with cognitive development at 10–12 years: a birth cohort in rural Western China

We aimed to comprehensively examine the association of breast-feeding, types and initial timing of complementary foods with adolescent cognitive development in low- and middle-income countries. We conducted a prospective cohort study of 745 adolescents aged 10–12 years who were born to women who participated in a randomised trial of prenatal micronutrient supplementation in rural Western China. An infant feeding index was constructed based on the current WHO recommendations. Full-scale intelligence quotient (FSIQ) was assessed and derived by the fourth edition of the Wechsler Intelligence Scale for Children. The duration of exclusive or any breast-feeding was not significantly associated with adolescent cognitive development. Participants who regularly consumed Fe-rich or Fe-fortified foods during 6–23 months of age had higher FSIQ than those who did not (adjusted mean differences 4·25; 95 % CI 1·99, 6·51). For cows’/goats’ milk and high protein-based food, the highest FSIQ was found in participants who initially consumed at 10–12 and 7–9 months, respectively. A strong dose–response relationship of the composite infant feeding index was also identified, with participants in the highest tertile of overall feeding quality having 3·03 (95 % CI 1·37, 4·70) points higher FSIQ than those in the lowest tertile. These findings suggest that appropriate infant feeding practices (breast-feeding plus timely introduction of appropriate complementary foods) were associated with significantly improved early adolescent cognitive development scores in rural China. In addition, improvement in Fe-rich or Fe-fortified foods complementary feeding may produce better adolescent cognitive development outcomes.

Appropriate age range for introduction of complementary feeding into an infant's diet

Following a request from the European Commission, the Panel on Nutrition, Novel Foods and Food Allergens (NDA) revised its 2009 Opinion on the appropriate age for introduction of complementary feeding of infants. This age has been evaluated considering the effects on health outcomes, nutritional aspects and infant development, and depends on the individual's characteristics and development. As long as foods have an age-appropriate texture, are nutritionally appropriate and prepared following good hygiene practices, there is no convincing evidence that at any age investigated in the included studies (< 1 to < 6 months), the introduction of complementary foods (CFs) is associated with adverse health effects or benefits (except for infants at risk of iron depletion). For nutritional reasons, the majority of infants need CFs from around 6 months of age. Infants at risk of iron depletion (exclusively breastfed infants born to mothers with low iron status, or with early umbilical cord clamping (< 1 min after birth), or born preterm, or born small-for-gestational age or with high growth velocity) may benefit from earlier introduction of CFs that are a source of iron. The earliest developmental skills relevant for consuming pureed CFs can be observed between 3 and 4 months of age. Skills for consuming finger foods can be observed in some infants at 4 months, but more commonly at 5-7 months. The fact that an infant may be ready from a neurodevelopmental perspective to progress to a more diversified diet before 6 months of age does not imply that there is a need to introduce CFs. There is no reason to postpone the introduction of potentially allergenic foods (egg, cereals, fish and peanut) to a later age than that of other CFs as far as the risk of developing atopic diseases is concerned. Regarding the risk of coeliac disease, gluten can be introduced with other CFs.

The Pregnancy and Birth to 24 Months Project: a series of systematic reviews on diet and health

Nutrition exposures during the earliest stages of life are integral to growth and development and may continue to affect health through adulthood. The purpose of the Pregnancy and Birth to 24 Months (P/B-24) Project was to conduct a series of systematic reviews on diet and health for women who are pregnant and for infants and toddlers from birth to 24 mo of age. The P/B-24 Project was a joint initiative led by the USDA and the US Department of Health and Human Services. The USDA's Nutrition Evidence Systematic Review team, previously known as the Nutrition Evidence Library, carried out the series of systematic reviews in collaboration with programmatic and scientific experts. Systematic review questions were prioritized based on federal policy, program, or guidance needs, potential to support the development of healthy dietary intake, and public health importance. Systematic reviews were conducted on specific topics related to dietary intake before and during pregnancy, infant milk feeding practices, complementary feeding, flavor exposures, and infant/toddler feeding practices. Across the reviews, relationships were observed between P/B-24 diet exposures and a variety of outcomes of public health importance. Evidence showed links between dietary intake before and during pregnancy, during the period of human milk or infant formula feeding, and through introduction of complementary foods and beverages and health outcomes. Additionally, the reviews on flavor exposure and infant/toddler feeding practices highlight the importance of maternal diet during pregnancy and lactation and caregiver feeding strategies and practices. Systematic reviews are an important tool to inform our understanding of the body of evidence related to diet and health, and scientists can use the P/B-24 Project reviews to continue to advance research in these areas.

Systematic review methods for the Pregnancy and Birth to 24 Months Project

The USDA's Nutrition Evidence Systematic Review (NESR) team specializes in conducting systematic reviews (SRs) to inform federal nutrition policy and programs. The NESR's dedicated staff collaborate with leading scientists to answer important food- and nutrition-related public health questions by objectively reviewing, evaluating, and synthesizing research using state-of-the-art methodology. NESR uses a rigorous, protocol-driven methodology that is designed to minimize bias; to ensure availability of SRs that are relevant, timely, and high quality; and to ensure transparency and reproducibility of findings. This article describes the methods used by NESR to conduct a series of SRs on diet and health in infants, toddlers, and women who are pregnant as part of the Pregnancy and Birth to 24 Months Project.