Lower protein in infant formula is associated with lower weight up to age 2 y: a randomized clinical trial

Amount and quality of dietary proteins during the first two years of life in relation to NCD risk in adulthood

During late infancy many infants have a protein intake, which is more than three times as high as the physiological need. Several observational studies have shown an association between a high-protein intake (>15 energy %) early in life and an increased risk of developing obesity and thereby non-communicable diseases (NCDs) later in life. This effect was supported by a recent intervention study with infant formulas with two levels of protein, showing that a higher protein intake during the first year of life resulted in a higher body mass index (BMI) at age 2 years. It is also plausible that an important reason for the slower growth in breast-fed infants is the lower content of protein in breastmilk, but other qualities of breastmilk could also play a role. A high intake of protein, especially dairy protein, stimulates the growth factors insulin-like growth factor (IGF-I) and insulin, and it has been suggested that the lower risk of NCDs in breast-fed infants is mediated through a regulation of IGF-I. A low quality of protein, as in cereal-based diets with no animal foods as often seen in low-income countries, may contribute to undernutrition, which can also result in an increased risk of NCDs later in life. In conclusion, there is some evidence that a high protein intake during the complementary feeding period is associated with increased risk of NCDs and that avoidance of a high protein intake could reduce the risk of obesity. In low-income countries, emphasis should be on providing sufficient amounts of high-quality protein to improve survival, growth and development.

How could complementary feeding patterns affect the susceptibility to NCD later in life?

AIMS

The purpose of this paper is to provide a general framework for thinking about pathways and potential mechanisms through which complementary feeding may influence the risk of developing non-communicable diseases (NCDs).

DATA SYNTHESIS

To provide a context for the lack of clear and consistent evidence relating complementary feeding to NCD risk, methodological challenges faced in trying to develop an evidence base are described. Potential pathways through which complementary feeding may influence obesity-related NCD risk are described and illustrated with examples.

CONCLUSIONS

Numerous aspects of complementary feeding, including diet composition as well as patterns of feeding have the potential to influence the early development of obesity, which in turn predicts later obesity and NCD risk. Specific dietary exposures during the period of complementary feeding also have the potential to program future disease risk through pathways that are independent of adiposity. These factors all require consideration when making recommendations for optimal complementary feeding practices aimed at prevention of future NCDs.

Is the macronutrient intake of formula-fed infants greater than breast-fed infants in early infancy?

Faster weight gain early in infancy may contribute to a greater risk of later obesity in formula-fed compared to breast-fed infants. One potential explanation for the difference in weight gain is higher macronutrient intake in formula-fed infants during the first weeks of life. A systematic review was conducted using Medline to assess the macronutrient and energy content plus volume of intake in breast-fed and formula-fed infants in early infancy. All studies from healthy, term, singleton infants reporting values for the composition of breast milk during the first month of life were included. The energy content of colostrum (mean, SEM: 53.6 ± 2.5 kcal/100 mL), transitional milk (57.7 ± 4.2 kcal/100 mL), and mature milk (65.2 ± 1.1 kcal/100 mL) was lower than conventional infant formula (67 kcal/100 mL) on all days analyzed. The protein concentration of colostrum (2.5 ± 0.2 g/100 mL) and transitional milk (1.7 ± 0.1 g/100 mL) was higher than formula (1.4 g/100 mL), while the protein content of mature milk (1.3 ± 0.1 g/100 mL) was slightly lower. Formula-fed infants consume a higher volume and more energy dense milk in early life leading to faster growth which could potentially program a greater risk of long-term obesity.

Biological determinants linking infant weight gain and child obesity: current knowledge and future directions

Childhood obesity rates have reached epidemic proportions. Excessive weight gain in infancy is associated with persistence of elevated weight status and later obesity. In this review, we make the case that weight gain in the first 6 mo is especially predictive of later obesity risk due to the metabolic programming that can occur early postpartum. The current state of knowledge regarding the biological determinants of excess infant weight gain is reviewed, with particular focus on infant feeding choice. Potential mechanisms by which different feeding approaches may program the metabolic profile of the infant, causing the link between early weight gain and later obesity are proposed. These mechanisms are likely highly complex and involve synergistic interactions between endocrine effects and factors that alter the inflammatory and oxidative stress status of the infant. Gaps in current knowledge are highlighted. These include a lack of data describing 1) what type of infant body fat distribution may impart risk and 2) how maternal metabolic dysfunction (obesity and/or diabetes) may affect milk composition and exert downstream effects on infant metabolism. Improved understanding and management of these early postnatal determinants of childhood obesity may have great impact on reducing its prevalence.

Bases biológicas e evidências epidemiológicas da contribuição do crescimento fetal e pós-natal na composição corporal: uma revisão

OBJETIVOS: apresentar as bases biológicas e evidências epidemiológicas do crescimento fetal e pós-natal relacionadas ao tamanho e composição corporal. MÉTODOS: a busca de artigos publicados nos últimos 15 anos foi realizada nas bases de dados Lilacs, SciELO, Medline através dos descritores: crescimento, restrição do crescimento fetal, baixo peso ao nascer, aceleração compensatória do crescimento, composição corporal, índice de massa corporal e hormônios. Os estudos foram selecionados de acordo com a pertinência às evidências a serem analisadas. RESULTADOS: os artigos apontam para a influência da restrição do crescimento intraútero na supressão da termogênese e regulação hormonal, que por sua vez interferem no ganho de peso após o nascimento, e explicam como ambos os processos, restrição do crescimento fetal e rápido ganho de peso pós-natal, influenciam as medidas corporais em fases posteriores da vida, com consequências que poderão afetar gerações. CONCLUSÕES: o crescimento fetal influencia o padrão de crescimento pós-natal devido a diversos fatores relacionados à regulação hormonal, porém existe ainda uma lacuna sobre a contribuição da somação entre crescimento fetal e pós-natal no tamanho e composição corporal em fases posteriores da vida.

Nutrition and growth: highlights from the first international meeting

The first International Conference on Nutrition and Growth brought together physicians, dietitians, nurses and scientists to discuss one of the major challenges of pediatric nutrition, namely growth. The meeting, which lasted for 2 and a half days, was well attended, with more than 1250 participants from 92 countries. This report reviews selected highlights from the conference.

Insulin-like growth factor 2/H19 methylation at birth and risk of overweight and obesity in children

OBJECTIVE

To determine whether aberrant DNA methylation at differentially methylated regions (DMRs) regulating insulin-like growth factor 2 (IGF2) expression in umbilical cord blood is associated with overweight or obesity in a multiethnic cohort.

STUDY DESIGN

Umbilical cord blood leukocytes of 204 infants born between 2005 and 2009 in Durham, North Carolina, were analyzed for DNA methylation at two IGF2 DMRs by using pyrosequencing. Anthropometric and feeding data were collected at age 1 year. Methylation differences were compared between children >85th percentile of the Centers for Disease Control and Prevention growth charts weight-for-age (WFA) and children ≤ 85th percentile of WFA at 1 year by using generalized linear models, adjusting for post-natal caloric intake, maternal cigarette smoking, and race/ethnicity.

RESULTS

The methylation percentages at the H19 imprint center DMR was higher in infants with WFA >85th percentile (62.7%; 95% CI, 59.9%-65.5%) than in infants with WFA ≤ 85th percentile (59.3%; 95% CI, 58.2%-60.3%; P = .02). At the intragenic IGF2 DMR, methylation levels were comparable between infants with WFA ≤ 85th percentile and infants with WFA >85th percentile.

CONCLUSIONS

Our findings suggest that IGF2 plasticity may be mechanistically important in early childhood overweight or obese status. If confirmed in larger studies, these findings suggest aberrant DNA methylation at sequences regulating imprinted genes may be useful identifiers of children at risk for the development of early obesity.

Early nutrition programming of long-term health

Increasing evidence from the EU Project EARNEST and many other investigators demonstrates that early nutrition and lifestyle have long-term effects on later health and the risk of common non-communicable diseases (known as 'developmental programming'). Because of the increasing public health importance and the transgenerational nature of the problem, obesity and associated disorders are the focus of the new EU funded project 'EarlyNutrition'. Currently, three key hypotheses have been defined: the fuel mediated 'in utero' hypothesis suggests that intrauterine exposure to an excess of fuels, most notably glucose, causes permanent changes of the fetus that lead to obesity in postnatal life; the accelerated postnatal weight gain hypothesis proposes an association between rapid weight gain in infancy and an increased risk of later obesity and adverse outcomes; and the mismatch hypothesis suggests that experiencing a developmental 'mismatch' between a sub-optimal perinatal and an obesogenic childhood environment is related to a particular predisposition to obesity and corresponding co-morbidities. Using existing cohort studies, ongoing and novel intervention studies and a basic science programme to investigate those key hypotheses, project EarlyNutrition will provide the scientific foundations for evidence-based recommendations for optimal nutrition considering long-term health outcomes, with a focus on obesity and related disorders. Scientific and technical expertise in placental biology, epigenetics and metabolomics will provide understanding at the cellular and molecular level of the relationships between early life nutritional status and the risk of later adiposity. This will help refine strategies for intervention in early life to prevent obesity.

Diet, sensitive periods in flavour learning, and growth

Diet in early infancy has an impact on early growth and the formation of flavour preferences, as well as on later life health outcomes. Although breast milk is the preferred source of nutrition during infancy, more than half of American infants receive infant formula by the age of 4 months. As a group, formula-fed infants weigh more by the age of one year and have a greater risk for later obesity than breastfed infants. However, a recent randomized study found that, when compared to breastfed infants, infants fed an extensively hydrolysed protein formula (ePHF) had more normative weight gain velocity than infants fed cow's milk formula (CMF). Therefore, grouping all formula-fed infants together with respect to certain health outcomes such as obesity may not be appropriate. Scientific evidence also suggests that there are sensitive periods for flavour learning. Infants become familiar with and learn to accept the flavours they experience through their mother's amniotic fluid and breast milk as well as formula. These early experiences influence flavour preferences of children that may affect food choices and therefore later life health. Further research on the influence of early diet on growth, flavour preferences, and food choices is imperative.

Mechanisms underlying the developmental origins of disease

It is well established that there is a relationship between patterns of early growth and subsequent risk of development of metabolic diseases such as type 2 diabetes and cardiovascular disease. Studies in both humans and in animal models have provided strong evidence that the early environment plays an important role in mediating these relationships. The concept of the developmental origins of health and disease is therefore widely accepted. The mechanisms by which an event in very early life can have a permanent effect on the long-term health of an individual are still relatively poorly understood. However a growing body of evidence has implicated a number of candidate mechanisms. These include permanent changes in an organ structure, programmed changes in gene expression through epigenetic modifications and persistent effects on regulation of cellular ageing. Understanding the extent and nature of these processes may enable the identification of individuals at risk of metabolic disease as well as providing insight into potential preventative and intervention strategies.

Determinants of infant formula use and relation with growth in the first 4 months

The wide variety of infant formula available on the market can be confusing for parents and physicians. We aimed to determine associations between predominant type of formula used from birth to 4 months and parental and child characteristics and type of physician consulted, and then to describe relations between type of formula used and growth. Our analyses included 1349 infants from the EDEN mother-child cohort. Infant's feeding mode and type of formula used were assessed at 4 months by maternal self-report. Infant's weight and height from birth to 4 months, measured in routine follow-up, were documented by health professionals in the infant's personal health record. Anthropometric z-scores were calculated by using World Health Organization growth standards. Multinomial logistic regression was used to identify factors associated with the type of formula predominantly used; relations with growth were analysed by linear regressions. Partially hydrolysed formulas were more likely to be used by primiparous women (P < 0.001), those breastfeeding longer (P < 0.001) and for infants with family history of allergies (P = 0.002). Thickened formulas were more often used by mothers returning to employment in the first 4 months (P = 0.05) and breastfeeding shortly (P < 0.001). No significant relation was found between infant's growth and type of formula (P > 0.20). Infants breastfed shorter showed higher weight-for-age (P < 0.001) and length-for-age (P = 0.001) z-score changes between birth and 4 months. The use of a specific type of infant formula seems to be mainly related to parental characteristics. Infant's growth in the first 4 months is related to other factors than to the type of formula used.

Need for early interventions in the prevention of pediatric overweight: a review and upcoming directions

Childhood obesity is currently one of the most prevailing and challenging public health issues among industrialized countries and of international priority. The global prevalence of obesity poses such a serious concern that the World Health Organization (WHO) has described it as a "global epidemic." Recent literature suggests that the genesis of the problem occurs in the first years of life as feeding patterns, dietary habits, and parental feeding practices are established. Obesity prevention evidence points to specific dietary factors, such as the promotion of breastfeeding and appropriate introduction of nutritious complementary foods, but also calls for attention to parental feeding practices, awareness of appropriate responses to infant hunger and satiety cues, physical activity/inactivity behaviors, infant sleep duration, and family meals. Interventions that begin at birth, targeting multiple factors related to healthy growth, have not been adequately studied. Due to the overwhelming importance and global significance of excess weight within pediatric populations, this narrative review was undertaken to summarize factors associated with overweight and obesity among infants and toddlers, with focus on potentially modifiable risk factors beginning at birth, and to address the need for early intervention prevention.

An index measuring adherence to complementary feeding guidelines has convergent validity as a measure of infant diet quality

The complementary feeding period is an important stage of child development. The study aim was to develop an index reflecting the degree of adherence to complementary feeding guidelines, evaluate its convergent validity, and explore associations with socio-demographic factors and dietary pattern scores in childhood. Data were analyzed from the Avon Longitudinal Study of Parents and Children (n = 6065) using parent-completed dietary questionnaires at 6 mo of age, socio-demographic information, and dietary patterns derived by principal component analysis at age 3 y. The Complementary Feeding Utility Index (CFUI) consists of 14 components: breastfeeding duration, feeding to appetite, timing of introduction to solids, exposure to iron-rich cereals, fruit and vegetable intake, exposure to high-fat/-salt/-sugar foods including sugary drinks, food texture, and meal/snack frequency. Regression analyses were undertaken to investigate associations between index scores, socio-demographic factors, food and nutrient intakes, and dietary pattern scores at age 3 y. Milk and food intake at 6 mo and nutrient intake at 8 mo of age varied across quintiles of index score in largely the expected directions. Associations were found among index score, maternal age, education, social class, maternal smoking history, and prepregnancy BMI. After adjustment for socio-demographic factors, the index score was associated with "processed" [β = -0.234 (95% CI = -0.260, -0.209)] and "healthy" [β = 0.185 (95% CI = 0.155, 0.215)] dietary pattern scores at age 3 y. The CFUI is able to discriminate across food intake, nutrient intake, and socio-demographic factors and is associated with later dietary patterns.

Early nutrition impact on the insulin-like growth factor axis and later health consequences

PURPOSE OF REVIEW

There is increasing interest in the role of insulin-like growth factor-I (IGF-I) in the relation between early growth and later risk of noncommunicable diseases (NCDs). This review presents and discusses a selection of recent publications on this topic.

RECENT FINDINGS

Nutrition during pregnancy and in preterm infants has an influence on IGF-I. Breastfeeding is associated with lower IGF-I values and the effect of early protein intake was confirmed in a large intervention study. IGF-I levels are associated with early obesity, but the relation is complex and differs with age. Further studies and reviews support that there is a programming of the IGF axis, with higher levels during early life being associated with lower levels in adulthood, which is likely to influence the risk of NCDs later in life.

SUMMARY

Recent studies support that IGF-I plays an important role in the complex association between early diet, growth and later health, but more studies are needed to better understand the role of IGF-I, especially in the early development of obesity. Studies with data on how IGF-I is influenced by early diet in studies of preterm infants and young children with undernutrition from low-income countries will be helpful in recommending optimal diets.

Infant regulation of intake: the effect of free glutamate content in infant formulas

BACKGROUND

We recently discovered that infants randomly assigned to a formula high in free amino acids (extensive protein hydrolysate formula; ePHF) during infancy consumed less formula to satiation and gained less weight than did infants fed an isocaloric formula low in free amino acids (cow milk formula; CMF).

OBJECTIVE

Because ePHF and CMF differ markedly in concentrations of free glutamate, we tested the hypothesis that the higher glutamate concentrations in ePHF promote satiation and satiety.

DESIGN

In this counterbalanced, within-subject study, infants <4 mo of age (n = 30) visited our laboratory for 3 sets of 2 consecutive infant-led formula meals over 3 test days. Infants were fed 1 of 3 isocaloric formulas during each first meal: CMF, ePHF, or CMF with added free glutamate to approximate concentrations in ePHF (CMF+glu). When infants signaled hunger again, they were fed a second meal of CMF. From these data, we calculated satiety ratios for each of the 3 formulas by dividing the intermeal interval by the amount of formula consumed during that particular first meal.

RESULTS

Infants consumed significantly less CMF+glu (P < 0.02) and ePHF (P < 0.04) than CMF during the first meals. They also showed greater levels of satiety after consuming CMF+glu or ePHF: satiety ratios for CMF+glu (P < 0.03) and ePHF (P < 0.05) were significantly higher than for CMF.

CONCLUSION

These findings suggest a role of free glutamate in infant intake regulation and call into question the claim that formula feeding impairs infants' abilities to self regulate energy intake.

Excessive Leucine-mTORC1-Signalling of Cow Milk-Based Infant Formula: The Missing Link to Understand Early Childhood Obesity

Increased protein supply by feeding cow-milk-based infant formula in comparison to lower protein content of human milk is a well-recognized major risk factor of childhood obesity. However, there is yet no conclusive biochemical concept explaining the mechanisms of formula-induced childhood obesity. It is the intention of this article to provide the biochemical link between leucine-mediated signalling of mammalian milk proteins and adipogenesis as well as early adipogenic programming. Leucine has been identified as the predominant signal transducer of mammalian milk, which stimulates the nutrient-sensitive kinase mammalian target of rapamycin complex 1 (mTORC1). Leucine thus functions as a maternal-neonatal relay for mTORC1-dependent neonatal β-cell proliferation and insulin secretion. The mTORC1 target S6K1 plays a pivotal role in stimulation of mesenchymal stem cells to differentiate into adipocytes and to induce insulin resistance. It is of most critical concern that infant formulas provide higher amounts of leucine in comparison to human milk. Exaggerated leucine-mediated mTORC1-S6K1 signalling induced by infant formulas may thus explain increased adipogenesis and generation of lifelong elevated adipocyte numbers. Attenuation of mTORC1 signalling of infant formula by leucine restriction to physiologic lower levels of human milk offers a great chance for the prevention of childhood obesity and obesity-related metabolic diseases.

Leucine signaling in the pathogenesis of type 2 diabetes and obesity

Epidemiological evidence points to increased dairy and meat consumption, staples of the Western diet, as major risk factors for the development of type 2 diabetes (T2D). This paper presents a new concept and comprehensive review of leucine-mediated cell signaling explaining the pathogenesis of T2D and obesity by leucine-induced over-stimulation of mammalian target of rapamycin complex 1 (mTORC1). mTORC1, a pivotal nutrient-sensitive kinase, promotes growth and cell proliferation in response to glucose, energy, growth factors and amino acids. Dairy proteins and meat stimulate insulin/insulin-like growth factor 1 signaling and provide high amounts of leucine, a primary and independent stimulator for mTORC1 activation. The downstream target of mTORC1, the kinase S6K1, induces insulin resistance by phosphorylation of insulin receptor substrate-1, thereby increasing the metabolic burden of β-cells. Moreover, leucine-mediated mTORC1-S6K1-signaling plays an important role in adipogenesis, thus increasing the risk of obesity-mediated insulin resistance. High consumption of leucine-rich proteins explains exaggerated mTORC1-dependent insulin secretion, increased β-cell growth and β-cell proliferation promoting an early onset of replicative β-cell senescence with subsequent β-cell apoptosis. Disturbances of β-cell mass regulation with increased β-cell proliferation and apoptosis as well as insulin resistance are hallmarks of T2D, which are all associated with hyperactivation of mTORC1. In contrast, the anti-diabetic drug metformin antagonizes leucine-mediated mTORC1 signaling. Plant-derived polyphenols and flavonoids are identified as natural inhibitors of mTORC1 and exert anti-diabetic and anti-obesity effects. Furthermore, bariatric surgery in obesity reduces increased plasma levels of leucine and other branched-chain amino acids. Attenuation of leucine-mediated mTORC1 signaling by defining appropriate upper limits of the daily intake of leucine-rich animal and dairy proteins may offer a great chance for the prevention of T2D and obesity, as well as other epidemic diseases of civilization with increased mTORC1 signaling, especially cancer and neurodegenerative diseases, which are frequently associated with T2D.

Long term metabolic impact of high protein neonatal feeding: a preliminary study in male rat pups born with a low birth weight

BACKGROUND & AIMS

Nutrition received in early life may impact adult health. The aim of the study was to determine whether high protein feeding in neonatal period would have long term metabolic effects in an animal model of low birth weight infants.

METHODS

Male rat pups born from dams receiving a low protein diet during gestation were separated from their mothers, and equipped with gastrostomy tubes to receive as their sole feeding a milk formula of either adequate protein (AP; n = 14; 8.7 g protein/dL; total energy: 155 kcal/100 g), or high protein content (HP; n = 14; 13.0 g protein/dL; total energy: 171 kcal/100 g) between the 7th (D7) and 21st day (D21) of life. Rats were then weaned to standard chow until sacrificed at adulthood.

RESULTS

At D18, HP feeding was associated with higher estimated rates of protein turnover (p = 0.007) and synthesis (p = 0.051), as assessed using l-[U-(13)C]valine infusion. HP milk feeding in early life was associated with an increase in weight gain from puberty through adulthood, along with an increase in food intake, serum insulin (179 ± 58 vs. 55 ± 7 pmol/L; means ± SE), pancreatic β-cell number, plasma triglycerides (95 ± 8 vs. 73 ± 9 mg/dL), serum leptin (9.7 ± 1.0 vs. 5.5 ± 1.2 ng/mL), mesenteric fat mass, and adipocyte size.

CONCLUSIONS

In an animal model of low birth weight infants, high protein neonatal feeding may have a lasting effect on fat and glucose metabolism, potentially leading to "metabolic syndrome" in adulthood.

Consumption of cow's milk as a cause of iron deficiency in infants and toddlers

Consumption of cow's milk (CM) by infants and toddlers has adverse effects on their iron stores, a finding that has been well documented in many localities. Several mechanisms have been identified that may contribute to iron deficiency in this young population group. The most important of these is probably the low iron content of CM, which makes it difficult for infants to obtain the amounts of iron needed for growth. A second mechanism is the occult intestinal blood loss associated with CM consumption during infancy, a condition that affects about 40% of otherwise healthy infants. Loss of iron in the form of blood diminishes with age and ceases after the age of 1 year. A third mechanism is the inhibition of non-heme iron absorption by calcium and casein, both of which are present in high amounts in CM. Fortification of CM with iron, as practiced in some countries, can protect infants and toddlers against CM's negative effects on iron status. Consumption of CM produces a high renal solute load, which leads to a higher urine solute concentration than consumption of breast milk or formula, thereby narrowing the margin of safety during dehydrating events, such as diarrhea. The high protein intake from CM may also place infants at increased risk of obesity in later childhood. It is thus recommended that unmodified, unfortified CM not be fed to infants and that it be fed to toddlers in modest amounts only.

Gene-environment interaction in chronic disease: a European Science Foundation Forward Look

Over the last half century, a dramatic increase in the incidence of chronic inflammatory diseases, such as asthma, allergy, and irritable bowel syndrome, has rightfully led to concern about how the modern lifestyle might inappropriately trigger innate physiologic defense mechanisms. Health care research in the Western world is faced with a significant challenge if it is to meet the needs of its populations in the decades ahead. The tools with which we hope to advance our understanding of the intrinsic and extrinsic mechanisms of chronic inflammatory diseases must therefore be adequately exploited and further developed to identify treatment and prevention strategies. There is an urgent need to prioritize resources and identify the most efficient scientific and societal initiatives to be adopted within this area. In this context national collaboration within Europe and beyond to establish state-of-the-art practices with an interdisciplinary perspective and promote an efficient exchange of best practices is essential. Such an approach likely represents the most efficient manner in which strategies for amelioration of the increase of chronic inflammatory diseases in the Western world can be achieved. The present report is based on a Forward Look initiative conducted by the European Medical Research Councils under the European Science Foundation. Experts from industry and academia, as well as relevant interest organizations, have been consulted in the process of conducting this initiative and have, based on this work, developed a set of final recommendations that target academic research, science funders, and policy makers.

Prevalence of overweight preschool children in public day care centers: a cross-sectional study

CONTEXT AND OBJECTIVE

Brazil is undergoing a period of epidemiological transition associated with demographic and nutritional changes. The prevalence of obesity is also increasing in children and is causing numerous health problems that are becoming public health issues. The aim here was to evaluate the prevalence of overweight among children of two and three years of age.

DESIGN AND SETTING

Cross-sectional study in municipal day care centers in Taubaté, state of São Paulo, Brazil.

METHODS

Weight and height measurements were made on 447 preschool children forming a probabilistic randomized sample. Their body mass index (BMI) was calculated. Their nutritional status was classified using the World Health Organization reference cutoff points (2006). Their mean weight, height and BMI were compared according to their age and sex.

RESULTS

The mean values for the final sample (n = 447) were as follows: mean age: 38.6 months (± 3.5) and Z scores for: weight/height (W/H): 0.50 (± 1.22); height/age: -0.03 (± 1.07); weight/age (W/A): 0.51 (± 1.23); and BMI: 0.51(± 1.23). The prevalence of overweight children (BMI > 1 z) was 28.86%, while the prevalence of underweight children (BMI < -2 z) was 0.89%. There were no differences in mean BMI among the two and three-year age groups (P = 0.66).

CONCLUSION

A high prevalence of overweight was observed in the sample of two and three-year-old children, with practically no malnutrition, thus showing that a significant nutritional transition may already be occurring, even in medium-sized cities of developing countries.

Impact of maternal physical activity and infant feeding practices on infant weight gain and adiposity

Increasing evidence supports the contribution of intrauterine environmental exposures on obesity risk in offspring. Few studies have included maternal and infant lifestyle factors. Our objective was to study the impact of maternal physical activity, infant feeding, and screen time on offspring weight gain and adiposity. In a prospective cohort study, 246 mothers underwent testing during pregnancy to assess glucose tolerance status and insulin sensitivity. Anthropometry and questionnaires on physical activity, infant feeding, and screen time were completed. Multiple-linear regression was performed to examine the impact of maternal and infant factors on infant weight gain and weight-for-length z-score at 1 year. Infant weight outcomes were negatively predicted by maternal pregravid vigorous/sport index and exclusive breastfeeding duration. After adjustment, each unit increase in maternal pregravid vigorous/sport index decreased infant weight gain by 218.6 g (t = 2.44, P = 0.016) and weight-for-length z-score by 0.20 (t = 2.17, P = 0.031). Each month of exclusive breastfeeding reduced infant weight gain by 116.4 g (t = 3.97, P < 0.001) and weight-for-length z-score by 0.08 (t = 2.59, P = 0.01). Maternal pregravid physical activity and exclusive breastfeeding duration are associated with weight gain and adiposity as early as 1 year of age.

The effects of varying protein and energy intakes on the growth and body composition of very low birth weight infants

Objective

To determine the effects of high dietary protein and energy intake on the growth and body composition of very low birth weight (VLBW) infants.

Study design

Thirty-eight VLBW infants whose weights were appropriate for their gestational ages were assessed for when they could tolerate oral intake for all their nutritional needs. Thirty-two infants were included in a longitudinal, randomized clinical trial over an approximate 28-day period. One control diet (standard preterm formula, group A, n = 8, 3.7 g/kg/d of protein and 129 kcal/kg/d) and two high-energy and high-protein diets (group B, n = 12, 4.2 g/kg/d and 150 kcal/kg/d; group C, n = 12, 4.7 g/kg/d and 150 kcal/kg/d) were compared. Differences among groups in anthropometry and body composition (measured with bioelectrical impedance analysis) were determined. An enriched breast milk group (n = 6) served as a descriptive reference group.

Results

Groups B and C displayed greater weight gains and higher increases in fat-free mass than group A.

Conclusion

An intake of 150 kcal/kg/d of energy and 4.2 g/kg/d of protein increases fat-free mass accretion in VLBW infants.

Lactobacillus fermentum CECT 5716 is safe and well tolerated in infants of 1-6 months of age: a randomized controlled trial

The objective of the study was to evaluate the safety and tolerance of an infant formula supplemented with Lactobacillus fermentum CECT5716, a probiotic strain isolated from breast milk, in infants of 1-6 months of age. A randomized double blinded controlled study including healthy infants was conducted. One month aged infants received a prebiotic infant formula supplemented with L. fermentum (experimental group) or the same formula without the probiotic strain (control group) for 5 months. The primary outcome of the study was average daily weight gain between baseline and 4 months of age. Secondary outcomes were other anthropometric data (length and head circumference), formula consumption, and tolerance. Incidence of infections was also recorded by pediatricians. No significant differences in weight gain were observed between both groups, neither at 4 months of age (29.0±7.8 vs 28.9±5.7g/day) nor at 6 months (25.1±6.1 vs 24.7±5.2g/day). There were no statistically significant differences in the consumption of the formulae or symptoms related to the tolerance of the formula. The incidence rate of gastrointestinal infections in infants of the control group was 3 times higher than in the probiotic group (p=0.018). Therefore, consumption of a prebiotic infant formula enriched with the human milk probiotic strain L. fermentum CECT5716 from 1 to 6 months of life is well tolerated and safe. Furthermore, the consumption of this formula may improve the health of the infants by reducing the incidence of gastrointestinal infections.

Sex differences in the endocrine system in response to protein intake early in life

BACKGROUND

Nutritional factors during a sensitive period can influence child development in a sex-related manner.

OBJECTIVE

Our aim was to investigate whether sex modulates the responses of relevant biochemical parameters and growth to different protein intakes early in life.

DESIGN

In a randomized controlled trial, formula-fed infants were assigned to receive formula with higher protein (HP) or lower protein (LP) content. The main outcome measures were insulin-like growth factor (IGF)-1 axis parameters, weight, length, BMI, leptin, and C-peptide/creatinine ratio at 6 mo of age. Dietary intake during the first 6 mo of life was also assessed.

RESULTS

The IGF-1 axis response to HP feeding was modulated by sex. Total and free IGF-1 and IGF binding protein 3 concentrations were higher in girls than in boys. Compared with the LP diet, the HP diet was associated with higher IGF-1 and lower IGF binding protein 2 secretion. The response to this HP content formula tended to be stronger in girls than in boys. The HP diet was associated with a higher C-peptide/creatinine ratio. The leptin concentration was higher in girls than in boys and was correlated to the IGF-1 axis parameters. No interaction between sex and nutritional intervention was shown on growth.

CONCLUSIONS

Our findings show that the endocrine response to a high protein diet early in life may be modulated by sex. The IGF-1 axis of female infants shows a stronger response to the nutritional intervention than does that of male infants, but there is no enhanced effect on growth. This trial was registered at clinicaltrials.gov as NCT00338689.

Milk protein intake, the metabolic-endocrine response, and growth in infancy: data from a randomized clinical trial

BACKGROUND

Protein intake in early infancy has been suggested to be an important risk factor for later obesity, but information on potential mechanisms is very limited.

OBJECTIVE

This study examined the influence of protein intake in infancy on serum amino acids, insulin, and the insulin-like growth factor I (IGF-I) axis and its possible relation to growth in the first 2 y of life.

DESIGN

In a multicenter European study, 1138 healthy, formula-fed infants were randomly assigned to receive cow-milk-based infant and follow-on formulas with lower protein (LP; 1.77 and 2.2 g protein/100 kcal) or higher protein (HP; 2.9 and 4.4 g protein/100 kcal) contents for the first year. Biochemical variables were measured at age 6 mo in 339 infants receiving LP formula and 333 infants receiving HP formula and in 237 breastfed infants.

RESULTS

Essential amino acids, especially branched-chain amino acids, IGF-I, and urinary C-peptide:creatinine ratio, were significantly (P < 0.001) higher in the HP group than in the LP group, whereas IGF-binding protein (IGF-BP) 2 was lower and IGF-BP3 did not differ significantly. The median IGF-I total serum concentration was 48.4 ng/mL (25th, 75th percentile: 27.2, 81.8 ng/mL) in the HP group and 34.7 ng/mL (17.7, 57.5 ng/mL) in the LP group; the urine C-peptide:creatinine ratios were 140.6 ng/mg (80.0, 203.8 ng/mg) and 107.3 ng/mg (65.2, 194.7 ng/mg), respectively. Most essential amino acids, IGF-I, C-peptide, and urea increased significantly in both the LP and HP groups compared with the breastfed group. Total IGF-I was significantly associated with growth until 6 mo but not thereafter.

CONCLUSIONS

HP intake stimulates the IGF-I axis and insulin release in infancy. IGF-I enhances growth during the first 6 mo of life. This trial was registered at clinicaltrials.gov as NCT00338689.

The introduction of solid food and growth in the first 2 y of life in formula-fed children: analysis of data from a European cohort study

BACKGROUND

Early introduction of solid food has been suspected to induce excessive infant energy intake and weight gain.

OBJECTIVE

The objective of this study was to test whether introduction of solid foods influences energy intake or growth.

DESIGN

Healthy, formula-fed infants who were recruited in 5 European countries were eligible for study participation. Anthropometric measurements were taken at recruitment and at 3, 6, 12, and 24 mo. Time of introduction of solid foods and energy intake were determined by questionnaires and 3-d weighed food records at monthly intervals. Age at introduction of solid food was categorized into 4 groups: ≤ 13 wk, 14-17 wk, 18-21 wk, and ≥ 22 wk.

RESULTS

Of 1090 recruited infants, 830 (76%) had data available for age at first introduction of solid food, and 671 (61%) completed the study until 24 mo of age. The median age at introduction of solid food was 19 wk. The time of introduction of solid foods was associated with country, sex, birth weight, parental education and marital status, and maternal smoking. Energy intake was higher in the first 8 mo of life in children with solid-food intake. Solid-food introduction did not predict anthropometric measures at 24 mo. Growth trajectories differed significantly: children with solid-food introduction in the first 12 wk experienced early catch-up growth, whereas those introduced to solid food at >22 wk of age grew more slowly and stayed on lower trajectories.

CONCLUSIONS

Solid foods do not simply replace infant formula but increase energy intake. Time of introduction of solid food has little influence on infant growth. This trial was registered at clinicaltrials.gov as NCT00338689.

Assessment of growth: variations according to references and growth parameters used

Numerous studies have investigated associations between early growth and future risk of obesity, but the methods used varied considerably. Different growth references or parameters can be considered. Growth references from France, the United States (the Centers for Disease Control and Prevention), the Netherlands, Belgium, and the United Kingdom were compared with World Health Organization (WHO) standards. For the first 3 mo of life, all references showed markedly lower values for weight, length, and body mass index (BMI) compared with WHO standards, but after the age of 6 mo references were generally higher than WHO standards. Compared with nonbreastfed infants, the growth of breastfed infants was generally closer to that of WHO standards. Because data in the WHO standards were collected on infants who were breastfed, the difference between references and WHO standards might be mainly attributable to feeding practices. Epidemiologic and clinical studies evaluated the consequences of using either WHO standards or national references and showed differences according to the reference used. Analyses of children's weight curves by physicians showed significant differences in the interpretation of child growth and therefore in the advice given to parents. Finally, the effect of using different growth parameters to predict future risk of obesity was examined and showed that weight and length gains may be good candidates to study future risks. In conclusion, because the reference or parameters used to assess growth have an important effect on the interpretation of growth, it is crucial to be aware of the consequences of the methods used in clinical or epidemiologic contexts.

Determinants of children's eating behavior

Parents have a high degree of control over the environments and experiences of their children. Food preferences are shaped by a combination of genetic and environmental factors. This article is a review of current data on effective determinants of children's eating habits. The development of children's food preferences involves a complex interplay of genetic, familial, and environmental factors. There is evidence of a strong genetic influence on appetite traits in children, but environment plays an important role in modeling children's eating behaviors. Parents use a variety of strategies to influence children's eating habits, some of which are counterproductive. Overcontrol, restriction, pressure to eat, and a promise of rewards have negative effects on children's food acceptance. Parents' food preferences and eating behaviors provide an opportunity to model good eating habits. Satiety is closely related to diet composition, and foods with low energy density contribute to prevent overeating. Parents should be informed about the consequences of an unhealthy diet and lifestyle and motivated to change their nutritional habits. Parents should be the target of prevention programs because children model themselves on their parents' eating behaviors, lifestyles, eating-related attitudes, and dissatisfaction regarding body image. Pediatricians can have an important role in the prevention of diet-related diseases. Informed and motivated parents can become a model for children by offering a healthy, high-satiety, low-energy-dense diet and promoting self-regulation from the first years of life.

Programming research: where are we and where do we go from here?

Convincing evidence has accumulated to show that both pre- and postnatal nutrition preprogram long-term health, well-being, and performance until adulthood and old age. There is a very large potential in the application of this knowledge to promote public health. One of the prerequisites for translational application is to strengthen the scientific evidence. More extensive knowledge is needed (eg, on effect sizes of early life programming in contemporary populations, on specific nutritional exposures, on sensitive time periods in early life, on precise underlying mechanisms, and on potential effect differences in subgroups characterized by, eg, genetic predisposition or sex). Future programming research should aim at filling the existing gaps in scientific knowledge, consider the entire lifespan, address socioeconomic issues, and foster innovation. Research should aim at results suitable for translational application (eg, by leading to health-promoting policies and evidence-based dietary recommendations in the perinatal period). International collaboration and a close research partnership of academia, industry, and small and medium enterprises may strengthen research and innovative potential enhancing the likelihood of translational application. The scientific know-how and methodology available today allow us to take major steps forward in the near future; hence, research on nutritional programming deserves high priority.

The Early Nutrition Programming Project (EARNEST): 5 y of successful multidisciplinary collaborative research

Differences in nutritional experiences during sensitive periods in early life, both before and after birth, can program a person's future development, metabolism, and health. A better scientific understanding of early nutrition programming holds enormous potential for implementing preventive strategies to enhance individuals' long-term health, well-being, and performance. This understanding could reduce costs of health care and social services and may enhance the wealth of societies. The Early Nutrition Programming Project (EARNEST) brought together a multidisciplinary team of international scientists and leaders in key areas of the early nutrition programming field from 40 major research centers across 16 European countries. The project had a total budget of 16.5 million Euros and was funded by the European Communities under the Sixth Framework Program for Research and Technical Development and coordinated by the Children's Hospital at Ludwig-Maximilians-University of Munich. The integrated program of work combined experimental studies in humans, prospective observational studies, and mechanistic animal work, including physiologic studies, cell culture models, and molecular biology techniques. The project lasted from April 2005 to October 2010. After the end of the project, the Early Nutrition Academy (http://www.early-nutrition.org) continues to serve as a platform for the exchange of information, scientific collaboration, and training activities in the area of programming. This article highlights some of the scientific results, achievements, and efforts of EARNEST.

Breastfeeding and body composition in children: will there ever be conclusive empirical evidence for a protective effect against overweight?

An increased prevalence of childhood overweight has been observed worldwide over the past decades, which indicates the need for strategies to prevent obesity. There is some evidence that risk of obesity is primed by exposures early in life. Among other factors, breastfeeding has been hypothesized as a potential priming factor against overweight. Although the properties of human milk suggest possible mechanisms for a protective effect of breastfeeding compared with formula feeding with respect to later overweight, empirical evidence is more difficult to establish. This article reviews the available epidemiologic literature on this topic. Several observational studies have shown evidence for a small protective effect with respect to overweight in childhood. Three meta-analyses reported significant protective effects of breastfeeding against overweight in later life, whereas another meta-analysis showed no effect of breastfeeding on mean body mass index (BMI) after adjustment for confounding factors. These seemingly inconsistent results might potentially be explained by different effects of breastfeeding in normal-weight compared with overweight children. Evidence from interventional studies is limited. A randomized trial failed to confirm an effect of a breastfeeding promotion on children's BMI, but this trial lacked statistical power because rates of breastfeeding were relatively similar in the intervention and control groups. In conclusion, protective priming effects of breastfeeding on later overweight appear to be possible but are difficult to prove. Although observational studies have to deal with confounding issues, interventional studies on breastfeeding promotion may lack power.

Long-term effects of hydrolyzed protein infant formulas on growth--extended follow-up to 10 y of age: results from the German Infant Nutritional Intervention (GINI) study

BACKGROUND

Previous analysis in a prospective, population-based cohort reported reduced weight gain in children fed extensively hydrolyzed casein (eHF-C) formula during the first year of life but showed no effect on growth between 1 and 6 y of life. No studies have been conducted in children up to the age of 10 y.

OBJECTIVE

The objective was to investigate potential differences in body mass index (BMI) over the first 10 y of life between infants fed within the intervention period of the first 16 wk of life with partially hydrolyzed whey (pHF-W), extensively hydrolyzed whey (eHF-W), eHF-C, or cow-milk formula (CMF) and infants exclusively breastfed (BF) within the intervention period.

DESIGN

This was a prospective, randomized, double-blind trial in full-term neonates with atopic heredity in the German birth cohort German Infant Nutritional Intervention (GINI) followed through the first 10 y of life. Analyses of absolute and World Health Organization (WHO)-standardized BMI trajectories for 1840 infants [pHF-W (n = 253), eHF-W (n = 265), eHF-C (n = 250), CMF (n = 276), and BF (n = 796)] were conducted according to intention-to-treat principles.

RESULTS

Except for the previously reported slower BMI gain in infants fed with eHF-C formula within the first year of life, no significant differences in absolute or WHO-standardized BMI trajectories were shown between the pHF-W, eHF-W, eHF-C, CMF, and BF groups thereafter up to the age of 10 y.

CONCLUSIONS

Extension of the follow-up period from 6 to 10 y for this randomized controlled trial showed no long-term consequences on BMI for the 4 infant formulas considered. These data need to be confirmed in future studies.

First steps for mommy and me: a pilot intervention to improve nutrition and physical activity behaviors of postpartum mothers and their infants

To assess the feasibility of a pediatric primary care based intervention to promote healthful behaviors among 0-6 month old infants and their mothers. We enrolled two intervention practices (60 mother-infant pairs) and one usual care control practice (24 pairs) in a non-randomized controlled trial. We completed visits and interviews with 80 (95%) pairs at birth and 6 months. The intervention included (1) brief focused negotiation by pediatricians, (2) motivational counseling by a health educator, and (3) group parenting workshops. We evaluated the intervention effects on infant feeding, sleep duration, TV viewing, and mothers' responsiveness to satiety cues. Maternal behavioral targets included postpartum diet, physical activity, TV and sleep. At 6 months, fewer intervention than control infants had been introduced to solid foods (57% vs. 82%; P=0.04), and intervention infants viewed less TV (mean 1.2 vs. 1.5 h/d; P=0.07). Compared to control infants, intervention infants had larger increases in their nocturnal sleep duration from baseline to follow up (mean increase 1.9 vs. 1.3 h/d; P=0.05); larger reductions in settling time (mean reduction -0.70 vs. -0.10 h/d; P=0.02); and larger reductions in hours/day of nighttime wakefulness (mean reduction -2.9 vs. -1.5 h/d; P=0.08). There were no differences in breastfeeding, response to satiety cues, or maternal health behaviors. A program of brief focused negotiation by pediatricians, individual coaching by health educators using motivational interviewing, and group parenting workshops tended to improve infant feeding, sleep and media exposure, but had less impact on mothers' own health-related behaviors.

High beverage sugar as well as high animal protein intake at infancy may increase overweight risk at 8 years: a prospective longitudinal pilot study

Background

Combined effects of early exposure to beverage sugar and animal protein and later life overweight risk have not been studied.

Methods

A prospective longitudinal study was initiated in 2001 with 226 infants between 4 and 13 months of age. Dietary intake was assessed with a 2 day food record. Also information on infant body weight and socio-economic status was obtained at baseline. At 8 year follow-up in 2009, children were surveyed again. Main outcome measure was overweight at 8 years as defined by BMIsds > = +1.0. Also maternal BMI, present dietary intake and physical activity, were obtained by questionnaire and 2-day food record.

Results

At the 8 year follow up, 120 children (53%) were surveyed again. Of those, questionnaires and food records were completed for 63 children, for the other 57 children only weight and height at 8 years was available; 20 out of 120 children (17%) were self-reported overweight at 8 years of age. Unadjusted odds ratios (ORs; 95% CI) for overweight at 8 years were 1.10 (1.02, 1.18) for beverage sugar intake per one percent of energy intake and 4.06 (1.50, 11.00) for the highest tertile of animal protein intake at infancy compared to the lowest two tertiles. After adjustment for sex, age, infant weight, breastfed at intake assessment, and socio-economic status, odds ratios were 1.13 (1.03, 1.24) for beverage sugar, and 9.67 (2.56, 36.53) for highest tertile of animal protein intake. In the subgroup with completed questionnaire (n = 63) ORs were also adjusted for current maternal overweight, more than 2 months full breastfeeding, physical activity, and energy intake, but ORs remained significantly associated with overweight at 8 years.

Conclusions

A high intake of sugar containing beverages as well as animal protein in the first year of life may increase the risk of overweight at 8 years. The results of this pilot investigation should be confirmed in a larger cohort.

Impact of perinatal prebiotic consumption on gestating mice and their offspring: a preliminary report

To assess the impact of prebiotic supplementation during gestation and fetal and early neonatal life, gestating BALB/cj dam mice were fed either a control or a prebiotic (galacto-oligosaccharides-inulin, 9:1 ratio)-enriched diet throughout pregnancy and lactation, and allowed to nurse their pups until weaning. At the time of weaning, male offspring mice were separated from their mothers, weaned to the same solid diet as their dam and their growth was monitored until killed 48 d after weaning. Prebiotic treatment affected neither the body-weight gain nor the food intake of pregnant mice. In contrast, at the time of weaning, pups that had been nursed by prebiotic-fed dams had a higher body weight (11.0 (se 1.2) g) than pups born from control dams (9.8 (se 0.9) g). At 48 d after weaning, significantly higher values were observed for colon length and muscle mass in the offspring of prebiotic-fed dams (1.2 (se 0.1) cm/cm and 5.7 (se 1.8) mg/g, respectively), compared with control offspring (1.1 (se 0.1) cm/cm and 2.9 (se 0.9) mg/g, respectively), without any difference in spleen and stomach weight, or serum leptin concentration. The present preliminary study suggests that altering the fibre content of the maternal diet during both pregnancy and lactation enhances offspring growth, through an effect on intestinal and muscle mass rather than fat mass accretion.

The Importance of Milk and other Animal-Source Foods for Children in Low-Income Countries

Background

Milk and other animal-source foods are concentrated dietary sources of macro- and micronutrients. Despite a global increase in milk production and consumption over the past decades, milk and other animal-source foods are often lacking in the diets of children in developing countries.

Objective

To evaluate the importance of milk and other animal-source food intake in promoting the growth, development, and health of children in low-income countries.

Methods

Original research articles describing observational and intervention studies with unfortified milk, fortified milk, and other animal-source foods in children were identified by searching the PubMed database.

Results

Consumption of milk and other animal-source foods by undernourished children improves anthropometric indices and cognitive function and reduces the prevalence of biochemical and functional nutritional deficiencies, reducing morbidity and mortality. Unfortified and fortified milk used in supplementation trials has been well tolerated and widely accepted by parents and children.

Conclusions

To improve the dietary quality of children in low-income countries and further the effort to eradicate extreme poverty and hunger in accordance with the United Nations Millennium Development Goals, additional research is necessary to identify and implement programs and policy supporting increased intake of milk and other animal-source foods.

Association of infant feeding practices in the general population with infant growth and stool characteristics

This was a prospective cohort study of 976 infants from birth to 12 months of age. Infants were fed breast milk, goat infant formula, cow infant formula, or a combination of formula and breast milk during the first 4 months of age. Data on type of milk feeding and infant growth (weight and height) were collected at birth and at 4, 8, and 12 months during routine clinical assessment. The number and consistency of bowel motions per day were recorded based on observational data supplied by the mothers. Infants fed breast milk or goat or cow infant formula during the first 4 months displayed similar growth outcomes. More of the infants fed cow infant formula had fewer and more well-formed bowel motions compared with breast-fed infants. The stool characteristics of infants fed goat formula resembled those of infants fed breast milk.

IGF-I and IGFBP-3 in healthy 9 month old infants from the SKOT cohort: breastfeeding, diet, and later obesity

BACKGROUND

High IGF-I concentrations in infancy have been associated with later obesity but the interactions between diet, IGF-I concentrations and growth in early life are complex and involve programming of the IGF-I axis.

OBJECTIVE

This paper examines how IGF-I and IGFBP-3 concentrations measured at age 9 months are related to diet and growth in infancy.

DESIGN

In the Danish SKOT cohort healthy term infants were included at age 9 months with follow-up at age 18 months. Total 252 infants had a full data set and were included in the analysis. Measurements include weight, length, skinfold thickness, waist circumference, 7-d food records, and blood analysis of IGF-I, and IGFBP-3.

RESULTS

Infants not being breastfed at 9 months of age (46%) had higher median IGF-I concentration than breastfed infants (51.6 vs. 44.2 ng/mL, P=0.0005) and there was a negative dose response effect of daily numbers of breastfeedings on IGF-I concentration. IGF-I concentration was negatively associated with birth weight and positively related to increase in weight, length and BMI between birth and 9 months. Between 9 months and 18 months of age increase in length was positively and increase in BMI was negatively related to IGF-I concentration.

CONCLUSION

Breastfeeding has a strong negative effect on IGF-I concentrations in late infancy. Although IGF-I concentrations at 9 months of age were negatively associated with change in BMI during the following 9 months we speculate that this could reflect an early adiposity rebound and thereby an increased risk of obesity later in life.

Milk lacking α-casein leads to permanent reduction in body size in mice

The major physiological function of milk is the transport of amino acids, carbohydrates, lipids and minerals to mammalian offspring. Caseins, the major milk proteins, are secreted in the form of a micelle consisting of protein and calcium-phosphate.

We have analysed the role of the milk protein α-casein by inactivating the corresponding gene in mice. Absence of α-casein protein significantly curtails secretion of other milk proteins and calcium-phosphate, suggesting a role for α-casein in the establishment of casein micelles. In contrast, secretion of albumin, which is not synthesized in the mammary epithelium, into milk is not reduced. The absence of α-casein also significantly inhibits transcription of the other casein genes. α-Casein deficiency severely delays pup growth during lactation and results in a life-long body size reduction compared to control animals, but has only transient effects on physical and behavioural development of the pups. The data support a critical role for α-casein in casein micelle assembly. The results also confirm lactation as a critical window of metabolic programming and suggest milk protein concentration as a decisive factor in determining adult body weight.

Developmental programming in response to maternal overnutrition

Metabolic disorders have seen an increased prevalence in recent years in developed as well as developing countries. While it is clear lifestyle choices and habits have contributed to this epidemic, mounting evidence suggests the nutritional milieu during critical stages of development in early life can "program" individuals to develop the metabolic syndrome later in life. Extensive epidemiological data presents an association between maternal obesity and nutrition during pregnancy and offspring obesity, and a number of animal models have been established in order to uncover the underlying mechanisms contributing to the programming of physiological systems. It is hard to distinguish the causal factors due to the complex nature of the maternal-fetal relationship; however, in order to develop adequate prevention strategies it is vital to identify which maternal factor(s) - be it the diet, diet-induced obesity or weight gain - and at which time during early development instigate the programmed phenotype. Curtailing the onset of obesity at this early stage in life presents a promising avenue through which to stem the growing epidemic of obesity.

The level of protein in milk formula modifies ileal sensitivity to LPS later in life in a piglet model

Background

Milk formulas have higher protein contents than human milk. This high protein level could modify the development of intestinal microbiota, epithelial barrier and immune functions and have long-term consequences.

Methodology/Principal findings

We investigated the effect of a high protein formula on ileal microbiota and physiology during the neonatal period and later in life. Piglets were fed from 2 to 28 days of age either a normoprotein (NP, equivalent to sow milk) or a high protein formula (HP, +40% protein). Then, they received the same solid diet until 160 days. During the formula feeding period ileal microbiota implantation was accelerated in HP piglets with greater concentrations of ileal bacteria at d7 in HP than NP piglets. Epithelial barrier function was altered with a higher permeability to small and large probes in Ussing chambers in HP compared to NP piglets without difference in bacterial translocation. Infiltration of T cells was increased in HP piglets at d28. IL-1β and NF-κB sub-units mRNA levels were reduced in HP piglets at d7 and d28 respectively; plasma haptoglobin also tended to be reduced at d7. Later in life, pro-inflammatory cytokines secretion in response to high doses of LPS in explants culture was reduced in HP compared to NP piglets. Levels of mRNA coding the NF-κB pathway sub-units were increased by the challenge with LPS in NP piglets, but not HP ones.

Conclusions/Significance

A high protein level in formula affects the postnatal development of ileal microbiota, epithelial barrier and immune function in piglets and alters ileal response to inflammatory mediators later in life.

Prenatal organochlorine compound exposure, rapid weight gain, and overweight in infancy

BACKGROUND

Although it has been hypothesized that fetal exposure to endocrine-disrupting chemicals may increase obesity risk, empirical data are limited, and it is uncertain how early in life any effects may begin.

OBJECTIVES

We explored whether prenatal exposure to several organochlorine compounds (OCs) is associated with rapid growth in the first 6 months of life and body mass index (BMI) later in infancy.

METHODS

Data come from the INMA (Infancia y Medio-Ambiente) Child and Environment birth cohort in Spain, which recruited 657 women in early pregnancy. Rapid growth during the first 6 months was defined as a change in weight-for-age z-scores > 0.67, and elevated BMI at 14 months, as a z-score ≥ the 85th percentile. Generalized linear models were used to estimate the risk of rapid growth or elevated BMI associated with 2,2-bis(p-chlorophenyl)-1,1-dichloroethylene (DDE), hexachlorobenzene, β-hexachlorohexane, and polychlorinated biphenyls in first-trimester maternal serum.

RESULTS

After multivariable adjustment including other OCs, DDE exposure above the first quartile was associated with doubling of the risk of rapid growth among children of normal-weight (BMI < 25 kg/m2), but not overweight, mothers. DDE was also associated with elevated BMI at 14 months (relative risk per unit increase in log DDE = 1.50; 95% confidence interval, 1.11-2.03). Other OCs were not associated with rapid growth or elevated BMI after adjustment.

CONCLUSIONS

In this study we found prenatal DDE exposure to be associated with rapid weight gain in the first 6 months and elevated BMI later in infancy, among infants of normal-weight mothers. More research exploring the potential role of chemical exposures in early-onset obesity is needed.