Distribution of energy and macronutrient intakes across eating occasions in European children from 3 to 8 years of age: The EU Childhood Obesity Project Study.

PURPOSE: We aimed to characterize the distribution of energy and macronutrient intakes across eating occasions (EO) in European children from preschool to school age. METHODS: Data from 3-day weighed food records were collected from children at ages 3, 4, 5, 6 and 8 years from Belgium, Germany, Italy, Poland and Spain. Food intakes were assigned to EO based on country-specific daytimes for breakfast, lunch, supper and snacks (morning, afternoon). The average energy and nutrient intakes were expressed as percentage of total energy intake (%E). Nutrients were additionally expressed as percentage per EO (%EEO). Foods were assigned to food groups; variation in intake was calculated via coefficient of variation (CV). We analyzed age trends in diurnal intake using mixed-effects beta regression. RESULTS: The 740 healthy children included in the analysis consumed the largest proportion of daily energy at lunch (31%E ± 8, M ± SD) and supper (26%E ± 8), followed by breakfast (19%E ± 7) and snacks [afternoon (16%E ± 8); morning (8%E ± 7)], with the most variable intake at morning snack (CV = 0.9). The nutrient composition at lunch and supper was highest for fat (36 ± 9%ELunch; 39 ± 11%ESupper) and protein (18 ± 5%ELunch; 18 ± 6%ESupper) and at breakfast and snacks for carbohydrates (54 ± 12%EBreakfast; 62 ± 12%ESnacks). High-sugar content foods were consumed in relatively large proportions at breakfast and snacks. Food intakes varied significantly with age, with lower snack intakes at later ages (p < 0.001). CONCLUSION: Possibly unhealthy EOs with high-fat intakes and high-sugar-content foods were observed. Changes in nutrient composition of EOs may be beneficial for health. TRIAL REGISTRY: ClinicalTrials.gov: NCT00338689; 19/June/2006.

Parental Perception of Body Weight Status of Their 8-year-old Children: Findings from the European CHOP Study.

BACKGROUND: Maternal perception of child weight status in children with overweight or obesity has received a lot of attention but data on paternal perception of children from presumably healthy cohorts are lacking. OBJECTIVE: We aimed to investigate paternal and maternal perception of child weight status at the age of 8 years in a cohort of 591 children from 5 European countries. MATERIAL AND METHODS: Included were 8-year-old children and their parents participating in the European Childhood Obesity Project (EU CHOP). Weight and height of children and parents were measured and Body Mass Index (BMI, kg/m2) was calculated. Both parents were asked to assess their perception of child weight status using Eckstein scales and their concern about child overweight. The agreement between mother and father perceptions was assessed by Cohen kappa coefficient and their relationship was analyzed by linear mixed effects models based on ordinal logistic regression, accounting for country, child gender and BMI, parental BMI, level of education, concern and type of feeding during first year of life. RESULTS: Data from children and both parents were available for 432 girls and boys. Mean BMI was comparable in boys and girls (16.7 ± 2.31 vs. 16.9 ± 2.87 kg/m2, P = 0.55). In total, 172 children (29.3%) were overweight or obese. There was a high degree of agreement between mother and father perceptions of their child's weight status (Cohen kappa 0.77). Multivariate modelling showed that perception levels significantly increased with child BMI but were globally lower than assessed. They differed between countries, gender and types of feeding during first year of life, were influenced by education level of the father but were not related to parental BMI and concern about childhood overweight. CONCLUSIONS: The study showed no overall differences between mothers and fathers in rating their child's weight status but both parents had a propensity to underestimate their child's actual weight, particularly in boys. The EU CHOP trial registered at clinicaltrials.gov as NCT00338689.

Commercial complementary food use amongst European infants and children: results from the EU Childhood Obesity Project.

PURPOSE: The objective of this secondary analysis is to describe the types of commercial complementary foods (CCF) consumed by infants and young children enrolled in the European Childhood Obesity Project (CHOP), to describe the contribution of CCF to dietary energy intakes and to determine factors associated with CCF use over the first 2 years of life. METHODS: The CHOP trial is a multicenter intervention trial in Germany, Belgium, Italy, Poland and Spain that tested the effect of varying levels of protein in infant formula on the risk for childhood obesity. Infants were recruited from October 2002 to June 2004. Dietary data on CCF use for this secondary analysis were taken from weighted, 3-day dietary records from 1088 infants at 9 time points over the first 2 years of life. RESULTS: Reported energy intakes from CCF during infancy (4-9 months) was significantly higher (p ≤ 0.002) amongst formula-fed children compared to breastfed children. Sweetened CCF intakes were significantly higher (p ≤ 0.009) amongst formula-fed infants. Female infants were fed significantly less CCF and infant age was strongly associated with daily CCF intakes, peaking at 9 months of age. Infants from families with middle- and high-level of education were fed significantly less quantities of CCF compared to infants with parents with lower education. Sweetened CCF were very common in Spain, Italy and Poland, with over 95% of infants and children fed CCF at 9 and 12 months of age consuming at least one sweetened CCF. At 24 months of age, 68% of the CHOP cohort were still fed CCF. CONCLUSIONS: CCF comprised a substantial part of the diets of this cohort of European infants and young children. The proportion of infants being fed sweetened CCF is concerning. More studies on the quality of commercial complementary foods in Europe are warranted, including market surveys on the saturation of the Western European market with sweetened CCF products.

BMI and recommended levels of physical activity in school children.

BACKGROUND: Physical activity (PA) and its health benefits are a continuous point of discussion. Recommendations for children's daily PA vary between guidelines. To better define the amount of PA necessary to prevent overweight and obesity in children, further research is needed. The present study investigates children's compliance to physical activity guidelines (PAGs) and the association between objectively measured PA and body mass index (BMI). METHODS: Participating children were 11 years old (n = 419) and part of the European CHOP trial, which was conducted in Germany, Belgium, Poland, Spain, Italy. At least 2 days of PA measurements were collected from each child using a SenseWear™ armband. BMI was calculated from children's height and weight. Thresholds of min·day-1 in PA needed to differentiate between normal and excess weight (overweight/obesity) were determined with Receiver Operator Characteristics (ROC) analysis. Additionally, adjusted linear and logistic regressions models were calculated for group differences and effects of a 5, 15 and 60 min·day-1 increases in PA on BMI. RESULTS: Median time spent in total PA was 462 min·day-1 (25th percentile; 75th percentile: 389; 534) and 75 min·day-1 (41; 115) in moderate to vigorous PA (MVPA). Girls spent 36 min·day-1 less in MVPA than boys and overweight/obese children 24 min·day-1 less than normal weight children (linear regression, p < 0.001). 63.2% of the children met PAGs of 60 min·day-1 in MVPA. The optimal threshold for min·day-1 in MVPA determined with ROC analysis was 46 min·day-1. Comparing 5, 15 and 60 min·day-1 increases in PA revealed that an additional 15 min·day-1 of vigorous PA had the same effect as 60 min·day-1 of MVPA. Sedentary time and light PA showed contrary associations to one another, with light PA being negatively and sedentary time being positively associated with excessive weight. CONCLUSIONS: Current PAGs are met by 2/3 of children and seem appropriate to prevent excess weight in children. An official recommendation of daily 15-20 min of vigorous PA and further reduction of sedentary time could help to fight youth overweight and thus be of potential public health importance. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT00338689 . Registered: June 19, 2006 (retrospectively registered).

Association of TAS2R38 variants with sweet food intake in children aged 1-6 years.

We aimed at studying whether genetic variants of the TAS2R38 gene are associated with energy intake from sweet tasting foods, total energy and macronutrient intake and body weight in children. Children (n = 691) from five European countries were genotyped for the first variant site rs713598 of the TAS2R38 bitter receptor gene. Three-day dietary records were obtained yearly from one to six years of age. Foods were categorized in sweet and non-sweet-tasting. Mixed models were used to describe group differences in food and nutrient intake and BMI z-score over time. TAS2R38 genotype was related to energy intake from sweet tasting foods: Children with PP and PA genotype consumed an average 83 kJ/d (95% CI 21 to 146; p = 0.009) more sweet tasting foods than children with AA genotype and a mean 56 kJ/d (95% CI 15 to 98; p = 0.007) more energy from energy dense sweet products. Intake of sweet tasting foods was lower in girls than boys and differed between countries. TAS2R38 genotype was not associated with the intake of energy, macronutrients, sugar, single food groups and BMI z-score. Despite many other factors influencing food preference and intake in children, actual intake of sweet food items is associated with TAS2R38 genotype. Children with PP or PA genotype consume more (energy dense) sweet tasting foods.

Protein intake in infancy and carotid intima media thickness at 5 years--a secondary analysis from a randomized trial.

BACKGROUND: Nutrition in childhood has an influence on the cardiovascular function later on in life. European Childhood Obesity Project is a multicenter, randomized clinical intervention trial examining the effect of early protein intake on later health outcomes, particularly adiposity and related disorders. The aim of the study was to examine the effect of nutritional intervention--different protein intake in infancy on carotid intima-media thickness (cIMT) at 5 years. The association of cardiovascular risk factors with cIMT was also assessed. METHODS: Healthy term formula-fed infants in five European countries were enrolled either to the higher (HP) or to the lower (LP) protein group. Observational group consisted of breastfed infants. Plasma insulin, glucose, lipid profile, IGF-1, apolipoprotein A1 and B were measured as well as anthropometric parameters of parents and a child, blood pressure and physical activity. RESULTS: No difference in cIMT between HP and LP group was observed. Insulin, HOMA-IR index and total IGF-1 were positively associated with cIMT but after adjustment for confounders only an inverse association between ApoA1 and positive between ApoB/ApoA1 and cIMT were significant. CONCLUSION: High versus low protein intake in infancy does not influence cIMT at 5 years. cIMT in healthy children at 5 years is associated with their apolipoprotein profile.

Rapid growth and childhood obesity are strongly associated with lysoPC(14:0).

BACKGROUND: Despite the growing interest in the early-origins-of-later-disease hypothesis, little is known about the metabolic underpinnings linking infant weight gain and childhood obesity. OBJECTIVE: To discover biomarkers reflective of weight change in the first 6 months and overweight/obesity at age 6 years via a targeted metabolomics approach. DESIGN: This analysis comprised 726 infants from a European multicenter randomized trial (Childhood Obesity Programme, CHOP) for whom plasma blood samples at age 6 months and anthropometric data up to the age of 6 years were available. 'Rapid growth' was defined as a positive difference in weight within the first 6 months of life standardized to WHO growth standards. Weight change was regressed on each of 168 metabolites (acylcarnitines, lysophosphatidylcholines, sphingomyelins, and amino acids). Metabolites significant after Bonferroni's correction were tested as predictors of later overweight/obesity. RESULTS: Among the overall 19 significant metabolites, 4 were associated with rapid growth and 15 were associated with a less-than-ideal weight change. After adjusting for feeding group, only the lysophosphatidylcholine LPCaC14:0 remained significantly associated with rapid weight gain (ß = 0.18). Only LPCaC14:0 at age 6 months was predictive of overweight/obesity at age 6 years (OR 1.33; 95% CI 1.04-1.69). CONCLUSION: LPCa14:0 is strongly related to rapid growth in infancy and childhood overweight/obesity. This suggests that LPCaC14:0 levels may represent a metabolically programmed effect of infant weight gain on the later obesity risk. However, these results require confirmation by independent cohorts.

Eating Frequency in European Children from 1 to 96 Months of Age: Results of the Childhood Obesity Project Study.

We aimed to investigate the eating frequency (EF) in children over age, and examined the influence of country, sex, feeding mode and weight status on EF. We used the dietary data of the Childhood Obesity Project, which comprised European children from five countries. Dietary data of 3-days weighed and estimated records were available monthly from 1 to 9 and at 12-, 24-, 36-, 48-, 60-, 72- and 96-months old. Generalized additive mixed effects models were used to estimate EF trajectories with EF as outcome and applying age splines. Additionally, the models were further adjusted for country, feeding mode, sex or weight status. Data from 1244 children were analysed. EF was highest at 1 month with on average 7.3 ± 1.9 feeds per day, and fell to 5.1 ± 1.1 eating occasions at the age 96 months. Night feeding was similarly often than day feeding at 1 month but declined thereafter. Significant differences in EF were observed between countries (p < 0.05), with the highest EF in Poland, and between infant feeding modes, with a higher EF in breastfed than non-breastfed infants (p < 0.05). Sex and body weight were not associated with EF. Despite the importance of EF towards total energy intake, no association with weight status was found.

Usefulness of the waist-to-height ratio for predicting cardiometabolic risk in children and its suggested boundary values.

BACKGROUND & AIMS: Only limited information is available on the usefulness of the waist-to-height ratio (WHtR) as an abdominal obesity marker in children. Our aim was to compare the ability of a WHtR >90th percentile, a WHtR ≥0.50, a WHtR ≥0.55 and a BMI z-score ≥2 SD to predict cardiometabolic risk in children followed-up at different ages. METHODS: We evaluated data from 660 children at 5, 8 and 11 years of age who participated in the Childhood Obesity Project trial in 5 European countries. We classified children with or without cardiometabolic (CMet) risk (yes vs. no) according to the presence of ≥2 parameters (blood pressure, HOMA-IR, triglyceride levels and high-density lipoprotein (HDL) cholesterol levels) ≥90th percentile. RESULTS: The odds ratio for CMet risk in children at all followed-up ages was statistically significant for all measures. The OR for the WHtR≥0.55 cut-off was 29.1 (5.6, 151.7) at 5 years of age, 11.8 (4.1, 33.8) at 8 year of age and 3.6 (1.7, 7.7) at 11 years of age, compared to the WHtR<0.55 cut-off. The WHtR≥0.55 cut-off showed a higher OR at younger ages than the BMI z-score ≥2SD, WHtR ≥90th percentile and WHtR≥0.50 cut-offs and a higher positive predictive value (82% at 5 years of age compared to 55%, 36% and 41%, respectively). CONCLUSION: A WHtR≥0.55 is a suitable cut-off for screening children at high cardiometabolic risk in the general young European population.

Effect of maternal smoking during pregnancy on child blood pressure in a European cohort.

Hypertension is a public health issue that can have its origin in the early phases of development. Maternal smoking during pregnancy (MSDP) could play a role in offspring's cardio-metabolic programming. To assess the relationship between MSDP and later blood pressure (BP) in children we conducted a secondary analysis of a randomized dietary intervention trial (EU-Childhood Obesity Project). Healthy term infants with normal birth weight were recruited during the first 8 weeks of life in 5 European countries and followed until 11 years of age. Data on MSDP was collected at recruitment. BP and anthropometry were assessed at 11 years of age. Children were classified according to AAP guidelines as normal BP: BP < 90th percentile; high BP: ≥ 90th percentile with the subset of children having BP > 95th percentile categorized as hypertensive. Out of 572 children, 20% were exposed to MSDP. At 11 years, 26.8% had BP over the 90th centile. MSDP beyond 12 weeks of gestation was associated with higher systolic BP percentile (adjusted B 6.935; 95% CI 0.454, 13.429; p = 0.036) and over twofold increase likelihood of hypertension (OR 2.195; 95% CI 1.089, 4.423; p = 0.028) in children at 11 years. MSDP was significantly associated with later BP in children.

Different protein intake in the first year and its effects on adiposity rebound and obesity throughout childhood: 11 years follow-up of a randomized controlled trial.

BACKGROUND AND OBJECTIVES: Infant feeding affects child growth and later obesity risk. We examined whether protein supply in infancy affects the adiposity rebound, body mass index (BMI) and overweight and obesity up to 11 years of age. METHODS: We enrolled healthy term infants from five European countries in a double blind randomized trial, with anticipated 16 examinations within 11 years follow-up. Formula-fed infants (n = 1090) were randomized to isoenergetic formula with higher or lower protein content within the range stipulated by EU legislation in 2001. A breastfed reference group (n = 588) was included. Adiposity rebound and BMI trajectories were estimated by generalized additive mixed models in 917 children, with 712 participating in the 11 year follow-up. RESULTS: BMI trajectories were elevated in the higher compared to the lower protein group, with significantly different BMI at adiposity rebound (0.24 kg/m2, 0.01-0.47, p = 0.040), and an increased risk for overweight at 11 years (adjusted Odds Ratio 1.70; 1.06-2.73; p = 0.027) but no significant difference for obesity (adjusted Odds Ratio 1.47; 0.66-3.27). The two formula groups did not differ in the timing of adiposity rebound, but all children with obesity at 11 years had an early adiposity rebound before four years. CONCLUSIONS: Compared to conventional high protein formula, feeding lower protein formula in infancy lowers BMI trajectories up to 11 years and achieves similar BMI values at adiposity rebound as observed in breastfed infants.

Dietary patterns acquired in early life are associated with cardiometabolic markers at school age.

BACKGROUND & AIMS: it has previously been described that dietary patterns established early in life tracked to late childhood. The aim of the present work was to analyse the association of dietary patterns that tracked from 2 to 8y with cardiometabolic markers at 8y of age. METHODS: The 3 identified patterns at 2y (that previous analyses showed to track to age 8y) were: "CoreDP", loaded for vegetables, fruits, fish, olive oil, etc.; "F&SDP", loaded by poor-quality fats and sugars; and "ProteinDP", mainly loaded by animal protein sources. Cardiometabolic markers at 8y were systolic blood pressure (SBP), insulin resistance (HOMA-IR), and triglycerides, and BMI z-score. To examine whether the association of diet with the outcomes was the result of a direct effect of diet at either two or 8y, or synergy between them, we used structural equation models. RESULTS: the associations between the patterns and the health outcomes were: CoreDP was inversely associated with SBP and HOMA-IR; ProteinDP was directly associated with HOMA-IR and SBP; and adherence to F&SDP was directly associated with triglycerides and SBP. The associations between the patterns and the health outcomes were independent of BMI and were the result of a direct effect of diet at 2y, an indirect effect of diet at 2y through diet at 8y or a combination between both pathways. CONCLUSION: dietary patterns acquired in early life, persisting to later childhood, were associated with cardiometabolic markers at school age independently of BMI.

Fibre Intake Is Associated with Cardiovascular Health in European Children.

BACKGROUND: We aimed at analysing the association between dietary fibre intake during childhood and cardiovascular health markers. METHODS: We used observational longitudinal analysis and recorded diet using 3-day diaries at the ages of 3, 4, 5, 6, and 8 years in children from the EU Childhood Obesity Project Trial. At the age of 8, waist circumference, systolic and diastolic blood pressure (SBP and DBP) and biochemical analyses (lipoproteins, triglycerides and homeostasis model for insulin resistance (HOMA-IR)) were evaluated. Those parameters were combined into a cardiometabolic risk score through the sum of their internal z-scores. RESULTS: Four-hundred children (51.8% girls) attended to the 8-year visit with a 3-day diary. Adjusted linear regression models showed that children who repeatedly stayed in the lowest tertile of fibre intake during childhood had higher HOMA-IR (p = 0.004), higher cardiometabolic risk score (p = 0.02) and a nonsignificant trend toward a higher SBP at 8 years. The higher the dietary intake of soluble fibre (from fruits and vegetables) at 8 years, the lower the HOMA-IR and the cardiometabolic risk score (p = 0.002; p = 0.004). SBP was directly associated with fibre from potatoes and inversely with fibre from nuts and pulses. CONCLUSION: A diet rich in dietary fibre from fruits, vegetables, pulses and nuts from early childhood was associated to a healthier cardiovascular profile, regardless of children's weight.

A simple method for identification of misreporting of energy intake from infancy to school age: Results from a longitudinal study.

BACKGROUND & AIMS: Misreporting is a major source of reporting bias in nutritional surveys. It can affect the analysis of associations between diet and disease. Although various methods have been proposed to identify misreporting, their application to infants and young children is difficult. We identify misreporting of energy intake in infants and young children and propose a simplified approach. METHODS: 1199 children were enrolled in the Childhood Obesity Programme (CHOP) based in 5 European countries (Belgium, Germany, Italy, Poland and Spain) with repeated measurements of 3-day weighed food protocol and anthropometric indices at 10 time points between ages 1-96 months. Individual cut-offs for the ratio of reported energy intake and estimated energy requirement were calculated to identify misreporters. Misreporting was studied according to age, gender, BMI z-scores and country. RESULTS: We identified a higher proportion of over-reporters (18.9%) as compared to under-reporters (10.6%). The proportion of over-reporting was higher among infants while under-reporting was more prevalent in school-aged children. Under-reporting was higher in boys (12.0%) and in obese/over-weight children (36.3%). Mean values for upper and lower cut-offs for the ratio of reported energy intake and estimated energy requirement in children ≤12 months were 0.80 and 1.20, and 0.75 and 1.25 for children >12 months, respectively. Using these fixed (mean) values, 90.4% (kappa statistic: 0.78) of all misreporters could be identified. CONCLUSIONS: Despite intensive measures to obtain habitual intake of children, an essential proportion of nutritional reports were found to be implausible. Both over- and under-reporting should be carefully analysed, even in studies on infants. Fixed cut-offs can be applied to identify misreporting if no individual variation in energy intake can be calculated. CLINICAL TRIAL REGISTRY: This trial was registered at https://clinicaltrials.gov/show/NCT00338689.

Complementary Feeding, Infant Growth, and Obesity Risk: Timing, Composition, and Mode of Feeding.

The complementary feeding period is a short transitional period from breastfeeding and formula feeding to family foods. Timing, quantity, and quality are implied to impact growth and obesity risk. We summarized the literature and analyzed data of monthly 3-day food diaries of >1,000 children from 5 European countries in the first 2 years of life, which were collected as part of the prospective European Childhood Obesity Project (CHOP Study). Formula-fed children started complementary food approximately 2 weeks earlier than breastfed children, and almost 40% of them at or before 4 months of age. While introduction of solids between 4 and 6 months or after 6 months does not seem to impact growth and later obesity risk, solids before 4 months of age increased the risk. There are indications that this is especially problematic for formula-fed children. During the complementary feeding period, fat intake decreases, and protein and carbohydrate intakes increase. Protein intake often exceeds European recommendations from 9 months onwards. However, the role of macronutrients during complementary feeding in growth and metabolism needs further clarification. Findings on the role of responsive feeding or baby-led feeding during complementary feeding in growth are not conclusive. In summary, while introduction of complementary foods before 4 months of age should be avoided, the impact of the quality of complementary food on short-term growth and later obesity risk has to be elucidated further.

DNA-Methylation and Body Composition in Preschool Children: Epigenome-Wide-Analysis in the European Childhood Obesity Project (CHOP)-Study.

Adiposity and obesity result from the interaction of genetic variation and environmental factors from very early in life, possibly mediated by epigenetic processes. Few Epigenome-Wide-Association-Studies have identified DNA-methylation (DNAm) signatures associated with BMI and body composition in children. Body composition by Bio-Impedance-Analysis and genome-wide DNAm in whole blood were assessed in 374 pre-school children from four European countries. Associations were tested by linear regression adjusted for sex, age, centre, education, 6 WBC-proportions according to Houseman and 30 principal components derived from control probes. Specific DNAm variants were identified to be associated with BMI (212), fat-mass (230), fat-free-mass (120), fat-mass-index (24) and fat-free-mass-index (15). Probes in genes SNED1(IRE-BP1), KLHL6, WDR51A(POC1A), CYTH4-ELFN2, CFLAR, PRDM14, SOS1, ZNF643(ZFP69B), ST6GAL1, C3orf70, CILP2, MLLT4 and ncRNA LOC101929268 remained significantly associated after Bonferroni-correction of P-values. We provide novel evidence linking DNAm with (i) altered lipid and glucose metabolism, (ii) diabetes and (iii) body size and composition in children. Both common and specific epigenetic signatures among measures were also revealed. The causal direction with phenotypic measures and stability of DNAm variants throughout the life course remains unclear and longitudinal analysis in other populations is required. These findings give support for potential epigenetic programming of body composition and obesity.

Maternal Smoking during Pregnancy and DNA-Methylation in Children at Age 5.5 Years: Epigenome-Wide-Analysis in the European Childhood Obesity Project (CHOP)-Study.

Mounting evidence links prenatal exposure to maternal tobacco smoking with disruption of DNA methylation (DNAm) profile in the blood of infants. However, data on the postnatal stability of such DNAm signatures in childhood, as assessed by Epigenome Wide Association Studies (EWAS), are scarce. Objectives of this study were to investigate DNAm signatures associated with in utero tobacco smoke exposure beyond the 12th week of gestation in whole blood of children at age 5.5 years, to replicate previous findings in young European and American children and to assess their biological role by exploring databases and enrichment analysis. DNA methylation was measured in blood of 366 children of the multicentre European Childhood Obesity Project Study using the Illumina Infinium HM450 Beadchip (HM450K). An EWAS was conducted using linear regression of methylation values at each CpG site against in utero smoke exposure, adjusted for study characteristics, biological and technical effects. Methylation levels at five HM450K probes in MYO1G (cg12803068, cg22132788, cg19089201), CNTNAP2 (cg25949550), and FRMD4A (cg11813497) showed differential methylation that reached epigenome-wide significance according to the false-discovery-rate (FDR) criteria (q-value<0.05). Whereas cg25949550 showed decreased methylation (-2% DNAm ß-value), increased methylation was observed for the other probes (9%: cg12803068; 5%: cg22132788; 4%: cg19089201 and 4%: cg11813497) in exposed relative to non-exposed subjects. This study thus replicates previous findings in children ages 3 to 5, 7 and 17 and confirms the postnatal stability of MYO1G, CNTNAP2 and FRMD4A differential methylation. The role of this differential methylation in mediating childhood phenotypes, previously associated with maternal smoking, requires further investigation.

Dietary protein intake affects amino acid and acylcarnitine metabolism in infants aged 6 months.

CONTEXT: The protective effect of breast-feeding against later obesity may be explained by the lower protein content compared with formula milk. However, the metabolic mechanisms remain unknown. OBJECTIVE: We studied the metabolic response to a higher or lower protein supply in infancy. DESIGN AND SETTING: The Childhood Obesity Project study is a double-blind, randomized, multicenter intervention trial. Infants were randomized to receive a higher (HP) or lower protein (LP) content infant formula or were breast-fed. PATIENTS AND INTERVENTIONS: Plasma samples of 691 infants who received formula milk with different protein content (HP, 2.05 g per 100 mL; LP, 1.25 g per 100 mL) or were breast-fed were collected. MAIN OUTCOME MEASURES: Changes in plasma amino acid and acylcarnitine concentrations of 6-month-old infants according to different dietary protein supply were determined by liquid chromatography coupled to tandem mass spectrometry. RESULTS: Twenty-nine metabolites differed significantly between the formula groups. Branched-chain amino acids (BCAAs) were the most discriminant metabolites. Their degradation products, the short-chain acylcarnitines C3, C4, and C5, were also significantly elevated in the HP group. A breakpoint analysis confirmed that with increasing BCAAs, the ratio between acylcarnitines and BCAAs decreases. Long-chain acylcarnitines were decreased in HP infants. CONCLUSIONS: BCAAs seem to play a pivotal role in the effect of a high-protein diet on ß-oxidation and fat storage. We provide new evidence for a possible saturation of the BCAA degradation pathway that may represent the mechanism by which high-protein intake affects the metabolic regulation. Moreover, it appears to inhibit the initial step of the ß-oxidation, thus leading to high early weight gain and body fat deposition.

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.

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.