Relations between high ponderal index at birth, feeding practices and body mass index in infancy

OBJECTIVE: We compared feeding practices between infants of high ponderal index (PI) at birth (PI above the 90th percentile) and normal PI at birth (PI between 10th and 90th percentiles), and examined how birth size and infant feeding practices were related to body mass index (BMI) at 12 months. DESIGN: In a cohort of 3000 infants invited to participate in a national Norwegian dietary survey, 1825 participated both at 6 and 12 months of age, and the present study included those born full term and with a PI (weight/length3) at birth > or =10th percentile (n=1441). Data on feeding practices were collected by food-frequency questionnaires, and anthropometrical data were measured by health-care personnel. RESULTS: A lower proportion of infants born with high PI were exclusively breastfed for at least 4 months compared with infants born with normal PI (37 and 47%, respectively; P=0.03). Earlier introduction of solid foods and higher consumption of some foods were also observed among infants of high PI. In a multivariate analysis, adjusted mean BMI (kg/m2) at 12 months was higher for infants of high PI at birth than for infants of normal PI (17.6 and 17.0, respectively; P<0.001) and higher for infants exclusively breastfed <3 months than for infants exclusively breastfed > or =3 months (17.5 and 17.2, respectively; P=0.001). CONCLUSIONS: High PI at birth was associated with a shorter duration of exclusive breastfeeding. Furthermore, high PI at birth and short-term exclusive breastfeeding were both associated with higher BMI at 12 months.     

婴幼儿期维生素D补充与一年级小学生超重肥胖的纵向关联

  目的  调查婴幼儿期维生素D补充状况及其对学龄初期超重肥胖的影响,为儿童肥胖的早期预防提供新思路。  方法  以8 744名上海市闵行区2019年9月1日入学,且于2019年10月8日至2020年1月17日进行了常规体检的小学一年级学生为研究对象,由专业医务人员按标准的方法和仪器测量儿童的身高、体重并计算体质量指数(BMI),以BMI界定超重肥胖,并回溯收集其出生记录与婴幼儿期维生素D补充、婴幼儿期喂养记录。采用非条件Logistic回归模型,拟合婴幼儿期维生素D补充对学龄初期超重肥胖的影响,并进一步根据出生后1,4,6月龄内是否纯母乳喂养进行分层分析。  结果  上海市闵行区一年级学生中,超重肥胖率为32.5%(2 843名);出生后1,2,4,6月龄内的婴儿维生素D补充率分别为20.2%,49.7%,66.3%,72.7%,有83.2%的婴幼儿在出生后3年内补充了维生素D。出生后1月龄内补充过维生素D的婴幼儿,学龄初期发生超重肥胖的风险降低(OR=0.82, 95%CI=0.68~0.98);分层分析结果显示,此保护作用在1,4,6月龄内为纯母乳喂养的婴儿中尤其明显[OR(95%CI)=0.76(0.61~0.97),0.76(0.59~0.99),0.69(0.49~0.98),P值均 < 0.05]。  结论  婴幼儿期维生素D补充率有待提高,婴幼儿期维生素D补充尤其对纯母乳喂养儿有降低学龄初期超重肥胖风险的作用。     

Milk feeding and dietary patterns predict weight and fat gains in infancy

Current guidelines recommend that infants are exclusively breast fed for the first 6 months of life, with particular solid foods being gradually introduced from 6 months. Our objective was to compare the growth of infants whose feeding most closely followed current guidelines with the growth of infants with other feeding practices. Participants were 1740 infants in a prospective cohort study in Southampton, UK. At 6 and 12 months, infants’ milk feeding was recorded, diets assessed using food frequency questionnaires (FFQ), and anthropometry performed. Principal components analysis was used to identify patterns of foods in the diet using the food intakes assessed by the FFQs. Two patterns (‘infant guidelines’ and ‘adult foods’) explained most variance in infant diet at 6 and 12 months of age. The main outcomes were conditional growth in weight, length and skinfold thickness from 0–6 and 6–12 months. Infants who were breast fed from 0–6 months gained weight, length and adiposity more slowly than formula‐fed infants, independent of age at introduction of solids and maternal factors: compared with infants who were breast fed from 0–6 months, formula‐fed infants gained 0.21 standard deviation scores (SDS) in weight [95% confidence interval (CI) 0.00, 0.42]. Infants whose dietary pattern was most similar to current feeding guidelines, with high frequencies of fresh fruit and vegetables, home‐prepared foods and breast milk, gained weight and skinfold thickness more rapidly from 6 to 12 months than other infants, independent of milk feeding, age at introduction of solids and maternal factors. Compared with infants in the lowest quarter, infants in the highest ‘infant guidelines’ score quarter gained 0.24 SDS [95% CI 0.06, 0.43] in weight and 0.26 SDS [95% CI 0.07, 0.45] in skinfold thickness. Conversely, infants whose diets had the highest frequencies of breads and processed foods gained weight less rapidly from 6 to 12 months than other infants. The extent to which the patterns of diet and growth we have described will influence the current or later health of infants is unknown. We are following up the infants in this study to assess the impact of these patterns beyond the first year of life. These associations should also be examined in other settings and populations.     

Vitamin D Supplementation in Exclusively Breastfed Infants Is Associated with Alterations in the Fecal Microbiome

Breastfeeding and introduction of solid food are the two major components of infant feeding practices that influence gut microbiota composition in early infancy. However, it is unclear whether additional factors influence the microbiota of infants either exclusively breastfed or not breastfed. We obtained 194 fecal samples from infants at 3–9 months of age, extracted DNA, and sequenced the V4 region of the 16S rRNA gene. Feeding practices and clinical information were collected by questionnaire and abstraction of birth certificates. The gut microbiota of infants who were exclusively breastfed displayed significantly lower Shannon diversity (p-adjust < 0.001) and different gut microbiota composition compared to infants who were not breastfed (p-value = 0.001). Among the exclusively breastfed infants, recipients of vitamin D supplements displayed significantly lower Shannon diversity (p-adjust = 0.007), and different gut microbiota composition structure than non-supplemented, breastfed infants (p-value = 0.02). MaAslin analysis identified microbial taxa that associated with breastfeeding and vitamin D supplementation. Breastfeeding and infant vitamin D supplement intake play an important role in shaping infant gut microbiota.     

The Influence of Infant Feeding Practices on Infant Mortality in Southern Africa

Objective To examine the adjusted and unadjusted effects of infant feeding practices on infant mortality in Southern Africa. Methods A merged dataset from the most recent Demographic and Health Surveys for Lesotho, Swaziland, Zambia and Zimbabwe was analysed using the Cox Proportional Hazard Model. A total number of 13,218 infants born in 5 years preceding all the surveys with information on infant feeding practices constituted the study population. Infant mortality was the outcome variable and infant feeding practices categorised into; no breastfeeding, partial breastfeeding and exclusive breastfeeding were the main explanatory variables. Maternal demographic and socio-economic characteristics and infants’ bio-demographic characteristics were also studied. Results Although, exclusive breastfeeding was quite low (12 %), exclusively breastfed infants exhibited a 97 % lower risk of dying during infancy compared to infants not breastfed in the region. Variations existed by country in the levels and patterns of both infant mortality and infant feeding practices. Mother’s country, highest level of education and marital status; child’s sex, birth weight and preceding birth interval were the significant predictors of infant mortality in Southern Africa. Conclusions Any form of breastfeeding whether exclusive or partial breastfeeding greatly reduces the risk of infant mortality with the greatest mortality reduction effect observed among exclusively breastfed infants in Southern Africa. To reduce the upsurge of infant mortality, there is the need to step up the effectiveness of child nutrition programmes that promote breastfeeding and put emphasis on exclusive breastfeeding of infants in the region.     

Infant feeding patterns in the Finnish type I diabetes prediction and prevention nutrition study cohort

OBJECTIVE: To investigate infant feeding patterns during the first 2 y and their relation to sociodemographic factors. DESIGN: A population-based cohort study. SETTING: Oulu and Tampere University Hospital district areas 1996-1999, Finland. SUBJECTS AND METHODS: All newborn infants (n=675) with increased genetic risk for type I diabetes were invited to the study in 1996-1997. Of these, 429 (64%) completed the dietary follow-up form by the time they reached 2 y of age. RESULTS: The median duration of exclusive breastfeeding (BF) was 1.8 months (range 0-6 months) and that of total BF 7.0 months (0.3-25 months). Among the infants 20% were exclusively breastfed at least 4 months (recommendation 4-6 months). Infants were introduced to infant formula at the median age of 1.8 months (range 0-25 months) and other supplementary foods at the median age of 3.5 months (1-6 months). Infant's ponderal index at birth was inversely associated with the duration of total BF. The age of introduction of supplementary foods correlated positively with the duration of total BF. Longer parental education and increased maternal age were associated with a longer duration of BF and older age at introduction of supplementary foods. Infant formula and other supplementary foods were added earlier to the diet of the boys than that of the girls. CONCLUSION: Duration of breastfeeding in Finland is shorter than recommended. Compliance with the current recommendations on the timing of introduction of first supplementary food and dairy products is relatively poor. The diet during infancy seems to be conspicuously influenced by the duration of parental education, maternal age and the sex of the infant.     

Breastfeeding, introduction of complementary foods, and adiposity at 5 y of age

BACKGROUND: Although dual-energy X-ray absorptiometry (DXA) is considered the most accurate measure of adiposity in children, it has rarely been used to examine the relation between infant feeding and adiposity during childhood. OBJECTIVE: The objective was to ascertain whether adiposity at age 5 y was related to breastfeeding, to the timing of the introduction of complementary foods during infancy, or to both. DESIGN: Body composition was measured in 313 children at age 5 y by using DXA. Data on breastfeeding, formula feeding, and the timing of the introduction of complementary foods were obtained from the mothers when the children were 3 y old. Regression analysis was used to examine the relation between infant feeding and fat mass after adjustment for lean body mass, sex, birth weight, maternal obesity, race, and other sociodemographic variables. RESULTS: Fifty-three percent of the children were boys, 80% were white, and 20% were black. There was no significant difference in adjusted fat mass between those ever breastfed and those never breastfed (x +/- SE: 4.48 +/- 0.09 and 4.76 +/- 0.17 kg, respectively; P = 0.17). Children who were breastfed for a longer duration and those who were breastfed without concurrent formula feeding did not have significantly lower fat mass than did those children who were never breastfed. Children did not differ significantly in fat mass if they were introduced to complementary foods before or after 4 mo of age (4.49 +/- 0.12 and 4.63 +/- 0.12 kg, respectively; P = 0.42). CONCLUSION: Neither breastfeeding nor the timing of the introduction of complementary foods was associated with adiposity at age 5 y.     

Breast and complementary feeding practices in relation to morbidity and growth in Malawian infants

OBJECTIVES: The objective of this study was to compare growth, morbidity incidence and risk factors for undernutrition between infants receiving complementary feeding early, before 3 months of age, with those receiving complementary foods after 3 months in a poor rural Malawian community. METHODS: A cohort of babies was enrolled at birth for follow-up to 12 months of age. Weight, length, morbidity and feeding patterns were recorded at 4 weekly intervals from birth to 52 weeks. RESULTS: Mean age at introduction of water was 2.5 months (range 0-11.8), complementary foods 3.4 months (range, 1.0-10.7) and solids 4.5 months (range 1.2-13.8). Over 40% of infants had received complementary foods by 2 months and 65% by 3 months. The proportion of exclusively breast-fed infants, which included those receiving supplemental water, was 13% at 4 months, 6.3% at 5 months and 1.5% at 6 months. Infants with early complementary feeding had lower weight for age at 3 and 6 months (P<0.05), and at 9 months (P=0.07) and at 2 months they were approximately 200 g lighter. Early complementary feeding was significantly associated with increased risk for respiratory infection (P<0.05), and marginally increased risk for eye infection and episodes of malaria. Maternal illiteracy was associated with early complementary feeding (OR=2.1, 95% CI 1.3, 3.2), while later complementary feeding was associated with reduced infant morbidity and improved growth. CONCLUSION: Breast-feeding promotion programmes should target illiterate women. Greater emphasis is required to improve complementary feeding practices.     

母乳喂养6月龄婴幼儿铁缺乏状况及其影响因素分析

目的了解母乳喂养儿6月龄铁营养状况及影响因素。方法选取马鞍山市妇幼保健院儿童保健科监测的足月、出生体重≥2 500g的健康婴儿作为研究对象,定期随访,调查其4月龄喂养方式,6月龄时进行末梢血常规和血清铁蛋白检测。结果母乳喂养6月龄婴幼儿铁缺乏的检出率明显高于人工喂养儿,差异具有统计学意义;其隐性铁缺乏的检出率高达23.2%;调整婴儿喂养方式、性别、孕周、母亲文化程度等混杂因素,进行多因素logistic回归分析,出生体重≤3 100g（OR=2.09,95%CI：1.20～3.61）和0～6月龄体重增长偏快（OR=2.03,95%CI：1.14～3.63）是纯母乳喂养儿铁缺乏的影响因素。结论对6月龄婴儿采取铁缺乏的普遍性筛查,及时评估铁缺乏危险因素,及早干预,对改善婴幼儿铁营养状况有重要意义。     

Associations of Feeding Practices in Early Life and Dietary Intake at School Age with Obesity in 10- to 12-Year-Old Arab Children

Understanding the role in pediatric obesity of early life feeding practices and dietary intake at school age is essential for early prevention. The study aimed to examine associations of early life feeding practices, environmental and health-related exposures, and dietary intake at school age as determinants of obesity in children aged 10–12 years. In an earlier study of 233 healthy infants in two Arab towns in northern Israel, neonatal history, feeding practices, and health information were obtained up to age 18 months. This follow-up study assessed dietary intake and anthropometric measurements at age 10–12 years using the 24 h recall method. Overall, 174 children participated in this study. Almost all (98%) the children were breastfed. The prevalence of obesity at school age was 42%. A multivariable model adjusted for energy intake and socioeconomic status showed positive associations of total fat intake and of weight-for-height z score, but not feeding practices in infancy, with obesity. Higher gestational age at birth was associated with lower odds of obesity at age 10–12 years. In conclusion, in a population with near universal breastfeeding, gestational age at birth, weight indicators but not feeding practices in infancy, and total fat intake at school age were associated with increased likelihood of obesity.     

Determinants of infant growth in the slums of Dhaka: size and maturity at birth, breastfeeding and morbidity

OBJECTIVE: To investigate the influences of size at birth, breastfeeding and morbidity on growth during infancy in poor areas of urban Bangladesh. DESIGN: This was a prospective observational study of a cohort of newborn infants followed until 12 months of age. SETTING: Slum areas of Dhaka City in Bangladesh. SUBJECTS: A total of 1654 newborn infants were enrolled at birth, and follow-up was completed for 1207 infants. Repeated anthropometric measurements and interviews of caretakers on infant feeding and morbidity were conducted. A mixed effects regression method was used for modeling infant growth. RESULTS: After adjusting for other variables, mean differences in body weight by birth weight and length, small-for-gestational age and prematurity categories remained relatively constant throughout infancy. A positive impact of exclusive breastfeeding in the first 3 5 months on infant growth was detectable at 12 months of age. Although the bigger babies in the sample tended to grow relatively even bigger; exclusive breastfeeding appeared to counteract this pattern. Reported diarrhoea was associated with lower body weights and lengths even after adjusting for feeding patterns. CONCLUSIONS: Size at birth has an important role in determining growth during infancy. Effective strategies for improving birth weight, poorly addressed till now in Bangladesh, are needed. The sustained effect on growth and the even more beneficial effect in lighter infants are compelling reasons for promotion of exclusive breastfeeding in early infancy.     

Growth pattern of exclusively breast-fed infants during the first six months of life in Ile-Ife,Osun State,Nigeria

Several studies to determine the growth pattern of exclusively breast fed infants have provided varying conclusions as to the sufficiency of breast milk alone to support adequate growth for the first six months of life. Disagreement exists concerning the optimal timing of introduction of complementary foods to exclusively breast fed infants. This prospective study thus examined the adequacy of breast milk alone to support normal growth during the first six months of life in our environment. The overall objective was to propose a scientifically sound national recommendation on the appropriate timing for the introduction of complementary feeding in Nigeria. Three hundred and fifty-two mother/infant pairs were serially recruited into the study; all babies were aged 14 days or less and weighed 2.5 kg and above. Three hundred and forty-five (98%) were successfully followed up till the infants were six months old. By six months, 264 (76.5%) were exclusively breast-fed, while 81 (23.5%) had commenced complementary feeding. Growth curves of exclusively breast-fed infants showed increasing weight from birth to six months. Although the 50th percentile birth weight for both boys and girls were the same (3.2 kg), boys gained weight faster than the girls from the age of one month to six months and were heavier at six months. Additionally, the 50th percentile curves of these infants (both genders) for the first six months were above the 50th percentile curve of the World Health Organisation and National Centre for Health Statistics (WHO/NCHS) reference currently used on our national "road to health" (growth monitoring) cards. It was concluded that exclusive breast-feeding supported adequate growth during the first six months of life for most of the children studied and that our national recommendation that infants be introduced to complementary feeding at six months is appropriate.     

How does infant behaviour relate to weight gain and adiposity?

An understanding of how infant eating behaviour relates to later obesity is required if interventions in infancy are to be attempted. The aim of this paper is to review findings from the Gateshead Millennium Study to describe (i) what we have already established about the relationship between infant feeding transitions, infancy weight gain and eating behaviour and (ii) describe new analyses that examine how infant eating behaviour and temperament relate to infancy weight gain and childhood adiposity. The Gateshead Millennium Study recruited 1029 infants at birth and parents completed questionnaires five times in the first year. We have already described how starting solids and ceasing breast-feeding seems to be a response to rapid early weight gain, rather than a cause, and that parents identify and respond to the individual appetite characteristics of their child. A number of questions about eating behaviour at 12 months were used to construct an infancy eating avidity score that was positively associated with height at age 7-8 years, but not with an adiposity index constructed using bioelectrical impedance, waist and skinfolds. Infancy eating avidity score was associated with greater fussiness and lower satiety responsivity on the Child Eating Behaviour Questionnaire at age 6-8 years. Temperament measured at age 6 weeks and 8 months showed no consistent associations with either infancy weight gain or adiposity at 6-8 years. While infancy may seem a logical time to intervene with children at risk of future obesity, the collective findings from this substantial population-based study largely suggest otherwise.     

Mode of infant feeding and achieved growth in adolescence: early feeding patterns in relation to growth and body composition in adolescence.

OBJECTIVE: Feeding mode in infancy and differences in childhood growth have been studied in several longitudinal studies, but few studies have followed children up to adolescent age. There is evidence that formula-fed infants weigh more and are taller than their breast-fed counterparts, and indications that this difference may sustain. RESEARCH METHODS AND PROCEDURES: We have studied the relations between length of breast-feeding, growth, and body composition in a group of 781 representatively chosen adolescents. Data on feeding pattern in infancy and on weight and height from birth up to 18 years were collected. We studied the relation between high body mass index (BMI) (defined as < or =85th percentile) in adolescence and length of breast-feeding. RESULTS: Girls who were not breast-fed or breast-fed for less than 3 months had a significantly higher height curve than girls exclusively breast-fed for more then 3 months. There were tendencies towards higher values of adipose tissue measured by skinfolds in girls breast-fed for 3 months or less. Short duration of exclusive breast-feeding was associated with higher BMI (p<0.04). In a subgroup of 194 adolescents, body composition was measured with dual energy X-ray. Both boys and girls who were exclusively breast-fed for more than 3 months were leaner and showed a trend towards lower skinfold values. CONCLUSION: These results are important to include in the debate about optimal feeding in infancy. Regarding breast-feeding as a standard, our results imply that formula fed infants may be at risk for overfeeding, which might lead to overweight, even up to adolescent age.     

On birth single dose live attenuated OPV and BCG vaccination induces gut cathelicidin LL37 responses at 6 week of age: A natural experiment

In a cross sectional study, we show that infants who received single dose of live attenuated OPV and BCG vaccines within 48 h of birth, have higher excretion of human cathelicidin LL37 (p < 0.05) in stool at 6 wk of age. This response remained unchanged in multivariate analysis after adjusting for sex, mode of delivery, infant age, mother age birth weight and breast milk feeding pattern. This analysis also reveals that irrespective of vaccination, girl infants have higher human-beta-defencin2 (HBD2) and exclusively breastfed infants have higher total and anti-polio specific IgA to all three subtypes in stool (p < 0.05). However, vaccination induces anti-polio IgA responses only to infants who are exclusively breastfed. Thus on-birth live attenuated vaccination may provide non-specific beneficial effect against infections while exclusive breastfeeding enhance protection by boosting vaccine induced IgA. The result also suggests that in polio endemic area, exclusive breastfeeding may be sufficient for mucosal anti-polio responses during early infancy.     

西部两县早产/低出生体重儿与正常足月儿的喂养情况比较

【目的】 比较我国西部两县早产/低出生体重儿(简称早产组)与正常足月儿(简称足月组)养护人的喂养知识和行为。 【方法】 利用对559名早产/低出生体重儿和522名足月儿的问卷调查资料的分析,应用χ²检验和方差分析比较早产组与足月组养护人的喂养知识及行为。 【结果】 早产组与足月组分别有56.5%和57.3%的养护人了解纯母乳喂养持续时间,34.5%和33.7%知道辅食添加的好处,33.8%和34.7%知道开始添加辅食的时间,差异均无统计学意义。早产组和足月组6个月以内纯母乳喂养的比例分别为26.6%和37.5%,添加辅食后目前仍继续母乳喂养的比例分别为7.1%和11.8%,差异均有统计学意义。早产组与足月组6个月开始添加辅食的比例(31.5%和32.6%)以及首次添加的辅食种类为铁强化婴儿营养米粉的比例(17.4%和20.6%)均相近。早产组每周摄入普通牛奶的比例高于足月组(54.4%和44.8%),差异有统计学意义;早产组与足月组每周摄入肉蛋类(66.8%和69.0%)、蔬果类(41.3%和40.7%)食物的比例以及出生后按时服用过补铁药物的比例(18.7%和19.6%)均接近,上述差异均无统计学意义。 【结论】 早产组与足月组养护人有关婴幼儿喂养知识均较缺乏,早产组采取不适宜喂养行为的比例更高。建议加强养护人对婴幼儿特别是早产/低出生体重儿的营养和喂养知识的健康教育。     

Systematic review concerning the age of introduction of complementary foods to the healthy full-term infant

OBJECTIVES: To evaluate existing data from published studies investigating outcomes (growth, nutritional status and morbidity) in relation to the age of introduction of complementary foods to the healthy full-term infant. To assess the methodological quality of current scientific evidence on which infant feeding recommendations are based. SEARCH STRATEGY: A database was created following a search of electronic databases MEDLINE and BIDS, a handsearch of relevant journals and consultation with international experts in infant feeding practices. The search was conducted during a 6-month period and encompassed the years 1982-1998. INCLUSION CRITERIA: Randomised/non-randomised controlled trials and cohort studies investigating the relationship to the health of full-term infants of the introduction of complementary foods to childhood health. DATA COLLECTION AND ANALYSIS: Assessment of studies for inclusion and their compliance with methodological criteria was undertaken independently by two reviewers and discrepancies were resolved by discussion. RESULTS: From over 400 published papers identified, 33 met specific inclusion criteria. Significant differences in baseline characteristics of subjects in included studies meant that data were not amenable to meta-analysis. The consensus of the authors was that, of the 33 included publications, 13 contained data supporting the current WHO recommendations which attempt to accommodate all infants, including those whose nutritional requirements are not met by exclusive breast-feeding for 6 months. An equal number contained data that would support a recommendation for delaying the introduction of complementary foods until 6 months of age within the study population. The remaining seven were unable to provide evidence to support a change from the current WHO infant feeding recommendations which state that 'infants should be fed exclusively on breast milk from birth to 4-6 months of age'. None of the studies met all the methodological criteria. CONCLUSIONS: This review has shown that there is a lack of clear evidence to either support or refute a change to the current recommendations for the age of introduction of complementary foods to the breast milk or formula fed infant. Whilst exclusive breast feeding for the first 6 months of life can support growth and development in some infants, sub-groups have been identified within certain populations who may require complementary feeding prior to this age.     

Session 4: Mineral metabolism and body composition iron status of breast-fed infants

Fe deficiency is a common nutritional disorder during infancy, particularly in low-income countries. The Fe status of a breast-fed infant is strongly influenced by the body Fe content at birth, which is determined by factors that operate before birth (maternal Fe status before and during pregnancy; infant gestational age and birth weight) and at the time of delivery (the timing of umbilical cord clamping). Delaying the clamping of the umbilical cord for 2 min can increase body Fe content by approximately 33% (75 mg), and results in greater Fe stores at 6 months of age. After birth, male gender and a rapid rate of weight gain are associated with lower Fe status. During the first half of infancy dietary Fe requirements depend on Fe stores at birth. For an exclusively-breast-fed full-term normal-birth-weight infant with delayed umbilical cord clamping, whose mother had adequate Fe status during pregnancy, the Fe provided from stores and breast milk is sufficient for >/=6 months, but before this time higher-risk infants may become Fe deficient. Fe supplementation can be beneficial for high-risk infants, but can have adverse effects on growth and morbidity of Fe-replete infants. After 6 months most breast-fed infants will require complementary foods that are rich in Fe.     

Breastfeeding and infant size: evidence of reverse causality

Infants who receive prolonged and exclusive breastfeeding grow more slowly during the first year of life than those who do not. However, infant feeding and growth are dynamic processes in which feeding may affect growth, and prior growth and size may also influence subsequent feeding decisions. The authors carried out an observational analysis of 17,046 Belarusian infants who were recruited between June 1996 and December 1997 and who participated in a cluster-randomized trial of a breastfeeding promotion intervention. To assess the effects of infant size on subsequent feeding, the authors restricted the analysis to infants breastfed (or exclusively breastfed) at the beginning of each follow-up interval and examined associations between weight or length at the beginning of the interval and weaning or discontinuation of exclusive breastfeeding by the end of the interval. Smaller size (especially weight for age) was strongly and statistically significantly associated with increased risks of subsequent weaning and of discontinuing exclusive breastfeeding (adjusted odds ratios = 1.2-1.6), especially between 2 and 6 months, even after adjusment for potential confounding factors and clustered measurement. The authors speculate that similar dynamic processes involving infant crying, other signs of hunger, and supplementation/weaning undermine causal inferences about the "effect" of prolonged and exclusive breastfeeding on slower infant growth.     

The EU Childhood Obesity Project

The European Union Childhood Obesity Project was set up in 2001 to test the hypothesis that the higher risk of obesity seen in formula‐fed infants – as compared with breastfed babies – is a result of the higher protein content in infant formulas than in breastmilk. The infants participating in the study were recruited between 2002 and 2004 and followed up for 2 years. The first results of the study were published earlier this year. After 2 years, the weight‐for‐length and body mass index of the infants fed the lower‐protein formula were significantly lower than those fed the higher‐protein formulas. Extrapolating from previous studies suggests that the children in the higher‐protein group have a 13% increased risk of being obese in adolescence compared with those in the lower‐protein group. An analysis of the timing of weaning has also been published: this showed that formula‐fed infants were given solid foods on average 2 weeks earlier than breastfed infants (19 weeks compared with 21 weeks) and were twice as likely to be introduced to solid foods before the age of 4 months as breastfed infants.