Infant feeding and obesity through the lifecourse

Feeding characteristics in infancy affect fruit and vegetable consumption and dietary variety in early childhood

BACKGROUND/OBJECTIVES

Previous studies have shown an association between breastfeeding and higher fruit and vegetable consumption and the level of dietary variety in children. However, few studies have reported this association on the feeding characteristics. Therefore, this study examined the association of the feeding characteristics with the consumption of fruit and vegetable and dietary variety in children.

SUBJECTS/METHODS

This study recruited 802 participants from their parents with information on their feeding, and 24-h dietary recall. The associations of the feeding characteristics with fruit and vegetable consumption and dietary variety score (DVS) were analyzed using a multiple logistic regression model.

RESULTS

Compared to the feeding type of exclusive breastfed children, exclusive formula-fed children had a significant association with a lower DVS (odds ratio [OR], 0.42, 95% confidence interval [CI], 0.23-0.77). Fruit and vegetable consumption was classified into 6 groups: non-salted vegetables (NSV), salted vegetables (SV), fruit (F), total vegetables (TV), non-salted vegetables + fruit (NSVF), and total vegetables + fruit (TVF). According to the mean level of fruit and vegetable consumption, compared to the duration of total breastfeeding for 6 month or less, a greater duration of breastfeeding for 12 mon had a significant association with a higher intake of NSVF and TVF (OR, 1.85, 95% CI, 1.20-2.85 and OR, 1.89, 95% CI, 1.22-2.92). On the other hand, the early introduction of formula feeding for 4 mon had a significant association with a lower intake of F and NSVF (OR, 0.59, 95% CI, 0.38-0.91 and OR, 0.63, 95% CI, 0.40-0.99).

CONCLUSIONS

These results confirm that breastfeeding is associated with higher fruit and vegetable consumption and dietary variety, whereas formula feeding is associated with lower fruit and vegetable consumption and dietary variety. Therefore, the feeding characteristics in infants may affect fruit and vegetable consumption and dietary variety in children.

Personalized Nutrition Approach in Pregnancy and Early Life to Tackle Childhood and Adult Non-Communicable Diseases

The development of childhood and adult non-communicable diseases (NCD) is associated with environmental factors, starting from intrauterine life. A new theory finds the roots of epigenetic programming in parental gametogenesis, continuing during embryo development, fetal life, and finally in post-natal life. Maternal health status and poor nutrition are widely recognized as implications in the onset of childhood and adult diseases. Early nutrition, particularly breastfeeding, also plays a primary role in affecting the health status of an individual later in life. A poor maternal diet during pregnancy and lack of breastfeeding can cause a nutrient deficiency that affects the gut microbiota, and acts as a cofactor for many pathways, impacting the epigenetic controls and transcription of genes involved in the metabolism, angiogenesis, and other pathways, leading to NCDs in adult life. Both maternal and fetal genetic backgrounds also affect nutrient adsorption and functioning at the cellular level. This review discusses the most recent evidence on maternal nutrition and breastfeeding in the development of NCD, the potentiality of the omics technologies in uncovering the molecular mechanisms underlying it, with the future prospective of applying a personalized nutrition approach to prevent and treat NCD from the beginning of fetal life.

Family Factors Associated with Selected Childhood Nutrition Aspects in Central Poland

Childhood diet has a significant influence on diet-related diseases in adulthood, so an understanding of environmental influences on nutrition, is important. The aim of this cross-sectional study was to indicate family factors associated with some aspects of children’s nutrition in Central Poland. A questionnaire was used to investigate 892 mothers’ approach to breastfeeding, frequency of eating with children at fast food restaurants, and serving them snacks, sugary drinks, and fried food. Prevalence of dental caries among children, based on the mothers’ self-assessment, was also assessed. Majority of the mothers breastfed for a period not longer than six months. There was a positive association between breastfeeding duration and mothers’ education level and the number of children in a family. Sweets were used as a reward, more often among younger children and in families with higher number of children. The frequency of consumption of sweet beverages rose with the child’s age and decreased with mother’s education level and family income. It was also more frequent in rural areas. Most children received snacks and fried food at least once a week. There was a negative association between eating with parents at fast food restaurants and, both, the number of children in the family and living in a village. Fast food consumption rose with the mother’s education level and family income. Prevalence of dental caries according to mothers’ declarations was much lower than in national studies but was associated with frequent consumption of snacks and sweet beverages in the examined population. Extensive activities to reduce the occurrence of dental caries at the national level and education concerning the role of a family environment in providing a proper childhood nutrition, with a special emphasis on breastfeeding benefits, seems necessary for Polish parents. Designing community-wide education campaigns referencing population-based programs and other health and disease prevention activities, need to be promoted.

Infant breastfeeding and childhood general, visceral, liver, and pericardial fat measures assessed by magnetic resonance imaging

Background

Although a longer duration of breastfeeding has been associated with a lower risk of childhood obesity, the impact on specific organ fat depots is largely unknown.

Objective

We examined the associations of any breastfeeding, duration and exclusiveness of breastfeeding, and of age at introduction of solid foods with measures of general, visceral, and organ adiposity at 10 y.

Design

In a population-based prospective cohort study in 4444 children, we obtained information on infant feeding by questionnaires. At the mean age of 9.8 y, we estimated body mass index from height and weight; fat mass index and fat-free mass index by dual-energy X-ray absorptiometry; and visceral fat index, pericardial fat index, and liver fat fraction by MRI. MRI scans were performed in a subgroup of 2646 children.

Results

After adjustment for age and sex, we observed associations of infant feeding with all general, visceral, and organ fat outcomes, except for pericardial fat index, at the age of 10 y. After further adjustment for family-based sociodemographic, maternal lifestyle-related, and childhood factors, only the associations of shorter breastfeeding duration and nonexclusive breastfeeding with a lower fat-free mass index remained significant (P < 0.05). The associations of infant feeding with visceral fat index and liver fat fraction were attenuated to nonsignificant. Maternal education was found to be the strongest confounder.

Conclusion

Our results suggest that the assoiations of any breastfeeding, duration and exclusiveness of breastfeeding, and age at the introduction of solid foods with general, visceral, and organ fat measures at the age of 10 y are largely explained by family-based sociodemographic factors.

Determinants of Cardiometabolic Risk Factors in the First Decade of Life: A Longitudinal Study Starting at Birth

The present prospective study assessed the association of birth weight (BW) and growth pattern on cardiometabolic risk factors in a cohort followed from birth to 10 years of age. One hundred and forty-five subjects (73 girls) who fulfilled the inclusion criteria and had all their data recorded at birth and at 5 years were enrolled. Of these, 100 (52 girls) also recorded data at 10 years. Anthropometric measurements, office and 24-hour blood pressure, and metabolic parameters were obtained. At 5 years, both BW and current weight were determinants of blood pressure and metabolic parameters; however, as the subjects got older, the impact of body size increased. Higher BW and maternal obesity increased the risk of becoming obese at 5 years while this was reduced if breastfeeding. Maternal obesity was the only factor associated with becoming obese at 10 years. Twenty-two children at 10 years had insulin values ≥15 U/L, some of whom were persistent from 5 years while in others it increased afterward. Subjects with insulin values ≥15 U/L showed significant higher values of office systolic blood pressure, triglycerides, and uric acid and lower values of high-density lipoprotein than did those with normal insulin values. Highest weight gain from 5 to 10 years and lowest BW were the main determinants of high insulin levels. In conclusion, although BW was a proxy of the events during fetal life and projected its influence later, the influence of gaining weight was a key determinant in the risk to develop obesity and metabolic abnormalities.

Excessive weight gain in exclusively breast-fed infants

BACKGROUND

Breastfeeding is recommended as the best source of nutrition in the first months of life and observational studies have associated exclusive breastfeeding with decreased weight gain and a protective effect against obesity in childhood. The objective of this study was to describe the characteristics of a cohort of exclusively breastfed obese infants to determine factors that may lead to this unusual weight gain.

METHODS

Infants seen between 2003 and 2015 who were exclusively breastfed and showed excessive weight gain in the first year of life were followed with a focus on features of the mother, the child, feeding patterns and the presence of concomitant factors that influence nutritional status. Additionally, in a subset of the sample, macronutrients of the maternal breast milk were analyzed. A descriptive, prospective cross-sectional study was conducted.

RESULTS

Of 73 patients, 63% were girls. At 3 months of life, 64% had a weight-for-height standard deviation score (SDS) >2. At 6 and at 12 months, 100% of the patients had a weight-for-height >2 SDS. The mean age at semisolid-food introduction was 7 months. The mean age at weaning was 15.8 months. The babies were fed on demand and no hunger-satiety pattern was observed. In the breast milk samples analyzed, a significantly lower fat content was found.

CONCLUSIONS

The results of our study lead to the assumption that inter-individual variations in mother's milk composition may affect the growth patterns of children.

Gene and environment interaction: Is the differential susceptibility hypothesis relevant for obesity?

The differential susceptibility model states that a given genetic variant is associated with an increased risk of pathology in negative environments but greater than average resilience in enriched ones. While this theory was first implemented in psychiatric-genetic research, it may also help us to unravel the complex ways that genes and environments interact to influence feeding behavior and obesity. We reviewed evidence on gene vs. environment interactions that influence obesity development, aiming to support the applicability of the differential susceptibility model for this condition, and propose that various environmental "layers" relevant for human development should be considered when bearing the differential susceptibility model in mind. Mother-child relationship, socioeconomic status and individual's response are important modifiers of BMI and food intake when interacting with gene variants, "for better and for worse". While only a few studies to date have investigated obesity outcomes using this approach, we propose that the differential susceptibility hypothesis is in fact highly applicable to the study of genetic and environmental influences on feeding behavior and obesity risk.

The accuracy of dietary recall of infant feeding and food allergen data

BACKGROUND

Research investigating the association of infant dietary factors with later health outcomes often relies on maternal recall. It is unclear what the effect of recall bias is on the accuracy of the information obtained. The present study aimed to determine the extent of recall bias on the accuracy of infant feeding and food allergen data collected 10 years later.

METHODS

Mothers were recruited from a prospective birth cohort from the Isle of Wight. When their child was 10 years of age (2011/2012), mothers were requested to complete a retrospective infant feeding questionnaire asking the same questions as those solicited in 2001/2002.

RESULTS

In total, 125 mothers participated. There was substantial agreement for recollection of any breastfeeding (κ = 0.79) and the duration of breastfeeding from 10 years earlier (r = 0.84). Some 94% of mothers recalled accurately that their child had received formula milk. The exact age at which formula milk was first given was reliably answered (r = 0.63). The brand of formula milk was poorly recalled. Recall of age of introduction of solid food was not reliable (r = 0.16). The age of introduction of peanuts was the only food allergen that was recalled accurately (86%).

CONCLUSIONS

The present study highlights the importance of maternal recall bias of infant feeding practices over 10 years. Recall related to breastfeeding and formula feeding were reliable, whereas recalls related to age of introduction of solid or allergenic foods, apart from peanut, were not. Caution should be applied when interpreting studies relying on dietary recall.

[DOHaD: long-term impact of perinatal diseases (IUGR and prematurity)]

The first epidemiological studies showing a link between low birth weight and chronic diseases in adults did not distinguish the origins of low birth weight. A low birth weight may be the result of a premature birth. It can also be caused by an intrauterine growth restriction (IUGR). A child can be both preterm and IUGR. It is clear now that prematurity is an independent risk factor for programming chronic adult diseases. However, unlike adults born IUGR, adults born prematurely do not have an increased risk to develop metabolic syndrome (dyslipidemia or obesity). An increased risk of neurodevelopmental and psychiatric morbidity and hypertension is found after a premature birth. Mechanisms of chronic diseases programming are multiple: they involve both the cause of prematurity and IUGR such as infection / inflammation or placental insufficiency, but also consequences for therapeutic or nutritional strategies needed to support these children. This chapter describes the possible prevention of perinatal programming of noncommunicable diseases.

Breastfeeding is associated with waist-to-height ratio in young adults

Background

The current study investigated the association between breastfeeding and adult weight distribution using an emerging indicator of weight distribution, the waist-to-height ratio (WHtR).

Methods

The study sample consisted of two subsamples of individuals that were part of the National Longitudinal Study of Adolescent Health. One sample (n = 1 179) consisted of individuals from the sibling pair data. A second sample (n = 4 648) consisted of individuals that were not part of the paired data. Regression models were constructed to establish if there was a relationship between breastfeeding and two measures of weight distribution: WHtR and body mass index (BMI). Controls for parental socioeconomic status, maternal smoking, race, sex, age, birth weight, maternal BMI, genetic ancestry, and a genetic risk score (GRS) for obesity were included. In addition, a behavioral risk score (BRS) was constructed to control for other residual confounding factors.

Results

A significant, inverse relationship between breastfeeding and adult WHtR persisted in models constructed from the sibling pair sample (P = 0.002) and unrelated sample (P <0.0001). This association remained significant with the inclusion of ancestry principal components, GRS, and a measure of maternal obesity.

Conclusions

The moderate association between breastfeeding and weight distribution persists into adulthood while controlling for potential confounders. This paper also provides evidence that the WHtR may be a superior outcome measure to BMI in studies investigating breastfeeding and obesity.

Electronic supplementary material

The online version of this article (doi:10.1186/s12889-015-2611-7) contains supplementary material, which is available to authorized users.

Association between Breastfeeding and Childhood Obesity: Analysis of a Linked Longitudinal Study of Rural Appalachian Fifth-Grade Children

INTRODUCTION

Although breastfeeding is associated with improving numerous health outcomes for the child, its role in reducing childhood obesity is contested. Despite this controversy, both the CDC and the US Department of Health and Human Services promote breastfeeding as one of the strategies for reducing childhood obesity. Rural Appalachia has one of the highest rates of childhood obesity and low rates of breastfeeding, compared to rest of the nation. The aim of this study was to examine the association between breastfeeding and childhood obesity at 11 years in the rural Appalachian state of West Virginia (WV).

METHODS

The study used linked data from two cross-sectional data sets to examine this relationship longitudinally in fifth-grade WV children. The main outcome variable was BMI adjusted percent (BMI%) and the main exposure was defined as occurrence of breastfeeding. Mean BMI% of children who were not breastfed was significantly higher, compared to children who were breastfed.

RESULTS

The result of the multiple regression analysis showed that breastfeeding significantly predicted BMI% of children after controlling for maternal education, health insurance, family history of hypercholesterolemia and diabetes, child's asthma status, and birth weight of the infant.

CONCLUSIONS

Our results are consistent with other studies that have shown a significant, but small, inverse association between breastfeeding and childhood obesity. Findings from this study suggest the need to improve breastfeeding rates in the rural Appalachian state of WV as one of the potential strategies to prevent obesity during childhood and adolescence.

The protective effects of breastfeeding on chronic non-communicable diseases in adulthood: A review of evidence

Chronic non-communicable diseases (NCDs), including cardiovascular diseases, cancers, chronic respiratory diseases, diabetes, etc., are the major causes of mortality in the world, notably in low- and middle-income countries. A growing body of evidence suggests that NCDs have a complex etiology resulting from the interaction of genetic factors, gender, age, ethnicity, and the environmental factors. It is well-documented that chronic diseases in adulthood origins in early life. In recent years, much attention has been focused on primordial and primary prevention of NCD risk factors. There are many biological and epidemiological studies on beneficial effects of breastfeeding during infancy on chronic diseases in adulthood, particularly on hypertension, obesity, diabetes, hypercholesterolemia, and cardiovascular diseases. This review article aims to summarize the current literature on the long-term effects of breastfeeding on prevention of NCDs and their risk factors.

The current literature is controversial about these effects; however, a growing body of evidence suggests that breastfeeding has protective roles against obesity, hypertension, dyslipidemia, and type II diabetes mellitus during adulthood. In addition to its short-term benefits, encouraging breastfeeding can have long-term beneficial health effects at individual and population levels.

The impact of maternal prenatal smoking on the development of childhood overweight in school-aged children

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

Maternal smoking during pregnancy likely increase the risk of childhood overweight. Childhood overweight is influenced by socioeconomic characteristics of mothers. Characteristics of child at birth determine the likelihood of overweight.

WHAT THIS STUDY ADDS

Children of mothers who smoked 1 year before birth (including pregnancy) were likely to be overweight during school ages than those of mothers who never smoked. Confirmation that socioeconomic characteristics of mothers influence the likelihood of childhood overweight during school age. Smoking cessation should be targeted at mothers 1 year before birth to improve their health status and that of offspring.

OBJECTIVES

To examine associations between maternal smoking and overweight among school-aged children and also identify mothers and offspring characteristics that affect children's weight.

METHODS

We used data from the National Institute of Child Health and Human Development (NICHD) Study of Early Child Care and Youth Development (SECCY). Childhood overweight was defined as having Body Mass Index (BMI) of 85th percentile or above. Smoking patterns among mothers were assessed by questioning smoking behaviour 1 year before birth of the target child: never or ever smoking. Standardized procedures were used to measure height and weight. Descriptive statistics and generalized estimating equations (GEE) were used for the analysis.

RESULTS

Descriptive results showed that children of mothers who smoked anytime within 1 year before birth were more likely to be overweight and have higher BMI percentile averages. GEE results showed that children of mothers who were ever smokers 1 year before birth were more likely to be overweight (OR = 1.39, 95% CI: 1.01, 1.94) and have higher BMI percentile averages (β = 4.46, P = 0.036) from grades 1 through 6 than those of mothers who were never smokers. Additionally, the level of mother's education and birth weight were significantly associated with childhood overweight.

CONCLUSIONS

Confirmed relationships between maternal smoking and overweight among school-aged children have important implications for public health policy because this evidence can be used to enhance smoking cessation 1 year before birth to improve the health status of mothers and offspring.

Effects of promoting longer-term and exclusive breastfeeding on adiposity and insulin-like growth factor-I at age 11.5 years: a randomized trial

IMPORTANCE

Evidence that longer-term and exclusive breastfeeding reduces child obesity risk is based on observational studies that are prone to confounding.

OBJECTIVE

To investigate effects of an intervention to promote increased duration and exclusivity of breastfeeding on child adiposity and circulating insulin-like growth factor (IGF)-I, which regulates growth.

DESIGN, SETTING, AND PARTICIPANTS

Cluster-randomized controlled trial in 31 Belarusian maternity hospitals and their affiliated clinics, randomized into 1 of 2 groups: breastfeeding promotion intervention (n = 16) or usual practices (n = 15). Participants were 17,046 breastfeeding mother-infant pairs enrolled in 1996 and 1997, of whom 13,879 (81.4%) were followed up between January 2008 and December 2010 at a median age of 11.5 years.

INTERVENTION

Breastfeeding promotion intervention modeled on the WHO/UNICEF Baby-Friendly Hospital Initiative (World Health Organization/United Nations Children's Fund).

MAIN OUTCOME MEASURES

Body mass index (BMI), fat and fat-free mass indices (FMI and FFMI), percent body fat, waist circumference, triceps and subscapular skinfold thicknesses, overweight and obesity, and whole-blood IGF-I. Primary analysis was based on modified intention-to-treat (without imputation), accounting for clustering within hospitals and clinics.

RESULTS

The experimental intervention substantially increased breastfeeding duration and exclusivity when compared with the control (43% vs 6% exclusively breastfed at 3 months and 7.9% vs 0.6% at 6 months). Cluster-adjusted mean differences in outcomes at 11.5 years of age between experimental vs control groups were: 0.19 (95% CI, -0.09 to 0.46) for BMI; 0.12 (-0.03 to 0.28) for FMI; 0.04 (-0.11 to 0.18) for FFMI; 0.47% (-0.11% to 1.05%) for percent body fat; 0.30 cm (-1.41 to 2.01) for waist circumference; -0.07 mm (-1.71 to 1.57) for triceps and -0.02 mm (-0.79 to 0.75) for subscapular skinfold thicknesses; and -0.02 standard deviations (-0.12 to 0.08) for IGF-I. The cluster-adjusted odds ratio for overweight/obesity (BMI ≥ 85th vs <85th percentile) was 1.18 (95% CI, 1.01 to 1.39) and for obesity (BMI ≥ 95th vs <85th percentile) was 1.17 (95% CI, 0.97 to 1.41).

CONCLUSIONS

AND RELEVANCE Among healthy term infants in Belarus, an intervention that succeeded in improving the duration and exclusivity of breastfeeding did not prevent overweight or obesity, nor did it affect IGF-I levels at age 11.5 years. Breastfeeding has many advantages but population strategies to increase the duration and exclusivity of breastfeeding are unlikely to curb the obesity epidemic.

TRIAL REGISTRATION

isrctn.org: ISRCTN37687716; and clinicaltrials.gov: NCT01561612.

A narrative literature review of the development of obesity in infancy and childhood

This narrative review explains the development of excess weight gain in babies and children. It takes a life course approach which includes genetics, pre-conception, pregnancy, infancy and childhood. The paper focuses on feeding behaviours, physical activity, parental influences and the wider social and environmental context. Risk factors which can cumulatively lead to excess childhood weight gain include: under- or overweight during pregnancy; the presence of diabetes during pregnancy; low or high birth weight; having obese parents; early weaning; prolonged formula feeding; rapid weight gain in the first year; disinhibited eating patterns and the consistent availability of energy dense food at home; feeding practices which are not responsive to the child's cues; insufficient sleep among preschool children; sedentary parents; low parental education; living in poor socio-economic circumstances; absence, or perceived absence, of safe play areas; parents who lack time or confidence to authoritatively parent; environments where there is poor access to affordable lower energy dense foods; and parents who do not accept that excess weight is a health problem. Recommendations for health professionals are made.

Breast feeding and the risk of obesity and related metabolic diseases in the child

Breast feeding is the best way to nurture healthy newborns of healthy mothers. A number of studies have shown that breast feeding may protect against the later development of obesity and related metabolic diseases. Using data from our own meta-analysis as well as studies by other groups, in this review we systematically examine the current state of evidence regarding this topic. Breast feeding, in general, is shown to be associated later in a child's life with decreased risk of overweight, decreased blood cholesterol and blood pressure, and a reduced risk of developing type 2 diabetes. Additionally, we review data of our Kaulsdorf Cohort Study (KCS) showing, however, that these effects might be reversed when the mother is affected by a non-communicable disease such as diabetes mellitus, which alters the composition of breast milk. In particular, exposure to breast milk from diabetic mothers during the first days of life (first week; early neonatal period) seems to increase rather than decrease risk of overweight and, consecutively, impaired glucose tolerance in childhood. Taken together, current findings show clearly that breast feeding is effective in lowering the risk of developing key features of the metabolic syndrome in later life, and should therefore be promoted. With increasing prevalence of overweight and diabetes in women, however, more research is urgently needed to clarify whether breast feeding might even have negative consequences for risk of overweight and diabetogenic disturbances when the mother suffers from a metabolic disorder. From a more general perspective, breast feeding and its long-term consequences are an important paradigm for "perinatal programming" of health and disease.

The Effect of Breast-Feeding with and without Formula Use on the Risk of Obesity at 4 Years of Age

OBJECTIVE

To determine the minimal duration of breast-feeding required to protect against later obesity, whether the concurrent use of formula lessened any protective effect of breast-feeding, and what maternal or child characteristics might modify the association between breast-feeding and child obesity.

RESEARCH METHODS AND PROCEDURES

This was a retrospective cohort study. Participants were 73,458 white and black low-income children followed from birth through 4 years of age. Obesity at age 4 years was defined as measured BMI >or= 95th percentile. Feeding exposure was based on breast-feeding duration and the age of formula initiation. Covariates were obtained from the children's birth certificates.

RESULTS

At age 4 years, the prevalence of obesity was 11.5%. Only 16% of children were breast-fed 8 weeks or longer. Breast-feeding was associated with a reduced risk of obesity only in white children whose mothers had not smoked in pregnancy. In this subgroup, the reduction in obesity risk (adjusted odds ratio, 95% confidence interval), compared with those never breast-fed, occurred only for children who were breast-fed at least 16 weeks without formula (0.71, 0.56 to 0.92) or at least 26 weeks with concurrent formula (0.70, 0.61 to 0.81). Among whites whose mothers smoked in pregnancy and among blacks, breast-feeding was not associated with a reduced risk of obesity at age 4 years.

DISCUSSION

In a population of low-income children, breast-feeding was associated with a reduced risk of obesity at age 4 years only among whites whose mothers did not smoke in pregnancy and only when breast-feeding continued for at least 16 weeks without formula or at least 26 weeks with formula.

Breastfeeding and risk of overweight and obesity at nine-years of age

Whether breastfeeding is protective against the development of childhood overweight and obesity remains the subject of considerable debate. Although a number of meta-analyses and syntheses of the literature have concluded that the greater preponderance of evidence indicates that breastfeeding reduces the risk of obesity, these findings are by no means conclusive. The present study used data from the Growing Up in Ireland study to examine the relationship between retrospectively recalled breastfeeding data and contemporaneously measured weight status for 7798 children at nine-years of age controlling for a wide range of variables including; socio-demographic factors, the child's own lifestyle-related behaviours, and parental BMI. The results of the multivariable analysis indicated that being breastfed for between 13 and 25 weeks was associated with a 38 percent (p < 0.05) reduction in the risk of obesity at nine-years of age, while being breastfed for 26 weeks or more was associated with a 51 percent (p < 0.01) reduction in the risk of obesity at nine-years of age. Moreover, results pointed towards a dose-response patterning in the data for those breastfed in excess of 4 weeks. Possible mechanisms conveying this health benefit include slower patterns of growth among breastfed children, which it is believed, are largely attributable to differences in the composition of human breast milk compared with synthesised formula. The suggestion that the choice of infant feeding method has important implications for health and development is tantalising as it identifies a modifiable health behaviour that is amenable to intervention in primary health care settings and has the potential to improve the health of the population.

Early markers of adult obesity: a review

The purpose of this review was to evaluate factors in early childhood (≤5 years of age) that are the most significant predictors of the development of obesity in adulthood. Factors of interest included exposures/insults in the prenatal period, infancy and early childhood, as well as other socio-demographic variables such as socioeconomic status (SES) or birth place that could impact all three time periods. An extensive electronic and systematic search initially resulted in 8,880 citations, after duplicates were removed. Specific inclusion and exclusion criteria were set, and following two screening processes, 135 studies were retained for detailed abstraction and analysis. A total of 42 variables were associated with obesity in adulthood; however, of these, only seven variables may be considered as potential early markers of obesity based on the reported associations. Possible early markers of obesity included maternal smoking and maternal weight gain during pregnancy. Probable early markers of obesity included maternal body mass index, childhood growth patterns (early rapid growth and early adiposity rebound), childhood obesity and father's employment (a proxy measure for SES in many studies). Health promotion programmes/agencies should consider these factors as reasonable targets to reduce the risk of adult obesity.

Early markers of adult obesity: a review

The purpose of this review was to evaluate factors in early childhood (≤5 years of age) that are the most significant predictors of the development of obesity in adulthood. Factors of interest included exposures/insults in the prenatal period, infancy and early childhood, as well as other socio-demographic variables such as socioeconomic status (SES) or birth place that could impact all three time periods. An extensive electronic and systematic search initially resulted in 8,880 citations, after duplicates were removed. Specific inclusion and exclusion criteria were set, and following two screening processes, 135 studies were retained for detailed abstraction and analysis. A total of 42 variables were associated with obesity in adulthood; however, of these, only seven variables may be considered as potential early markers of obesity based on the reported associations. Possible early markers of obesity included maternal smoking and maternal weight gain during pregnancy. Probable early markers of obesity included maternal body mass index, childhood growth patterns (early rapid growth and early adiposity rebound), childhood obesity and father's employment (a proxy measure for SES in many studies). Health promotion programmes/agencies should consider these factors as reasonable targets to reduce the risk of adult obesity.

Etiologies of obesity in children: nature and nurture

Childhood obesity is a profoundly complex problem and serves as an example of a biospsychosocial issue. Scientific inquiry has provided incredible insight into the complex etiology of weight gain but must be viewed as an interaction between a human's propensity to conserve calories for survival in a world with an abundance of it. This article provides a brief overview divided between biological (nature) and psychosocial and behavioral (nurture) factors.

Breastfeeding and obesity in Brazilian children

BACKGROUND

The association between breastfeeding and obesity is inconsistent by the literature. This study aims to assess whether obesity is associated to occurrence of breastfeeding and to duration of total and exclusive breastfeeding in Brazilian children.

METHODS

A cross-sectional study was conducted with 764 children enrolled in public and private schools from Viçosa, Minas Gerais, Brazil. Obesity (outcome variable) was defined as body mass index above the +2 standard deviations score using sex and age specific standards of World Health Organization. Exposure was the occurrence and duration of breastfeeding. Potential confounders were controlled by multiple logistic regression analysis and were divided in two groups: children (gender, age, birth weight, gestational age, order of birth, number of siblings, number of persons in the residence, type of school, physical activity patterns and time watching television) and mothers (age, nutritional status, level of education, weight gain during pregnancy, smokes currently and during the pregnancy).

RESULTS

Prevalence of obesity was 10.7%; 6.8% of the children were not breastfed and 59.0% did not receive exclusive breastfeeding. After adjustment for confounding variables by logistic regression analysis, no statistically significant association was observed between obesity and the occurrence and/or duration of total and exclusive breastfeeding. There was no dose-response effect of duration of breastfeeding on prevalence of obesity.

CONCLUSION

Our results do not support the hypothesis that breastfeeding promotion would reduce obesity in this population. Controversial findings regarding this association by literature indicate a need for further investigations.

The Terneuzen Birth Cohort. Longer exclusive breastfeeding duration is associated with leaner body mass and a healthier diet in young adulthood

Background

Breastfeeding (BF) is protective against overweight and is associated with dietary behaviour. The aims of our study were to assess the relationship between exclusive BF duration and BMI, waist circumference (WC) and waist-hip ratio (WHR) at adulthood, and to study whether dietary behaviour could explain the relationship between BF duration and the proxies of fat mass.

Methods

In 2004-2005, 822 subjects from the Terneuzen Birth Cohort (n = 2,604), aged 18-28 years, filled in postal questionnaires including sociodemographic factors and aspects of dietary behaviour (dietary pattern, and consumption of fruit and vegetables, snacks, sweetened beverages and alcohol); 737 subjects also underwent anthropometric measurements of weight, height, and waist and hip circumference. The relationship between exclusive BF duration and dietary outcomes was investigated by logistic regression analysis. The relationships of BF duration with the anthropometric measures were investigated by linear regression analyses. All results were corrected for age, gender and possible confounders. Finally, regression analyses were performed to investigate if diet factors had a mediating effect on the relationship between BF duration and fat mass.

Results

A significant inverse dose-response relationship of BF duration was found for BMI (β-0.13, SE 0.06), WC (β-0.39, SE 0.18) and WHR (β-0.003, SE 0.001), after correction for age, gender and confounders. The odds ratio (OR) of exclusive BF duration in months for a breakfast frequency of at least 5 times a week was 1.16 (95%CI 1.06-1.27), and for snack consumption of less than twice a week was 1.15 (95%CI 1.06-1.25). Both ORs were corrected for age, gender and confounders. For other dietary outcomes, the results point in the same direction, i.e. a positive relationship with BF duration, but these were not statistically significant. A mediating effect of the diet factors on the association between BF and anthropometric outcomes was not shown.

Conclusions

Exclusive BF duration had a significant inverse dose-response relationship with BMI, WC and WHR at young adulthood. BF duration was positively related to a healthier diet at adulthood, but this did not explain the protective effect of BF against body fat. Our results underline the recommendation of the WHO to exclusively breastfeed for 6 months or longer.

Breastfeeding and obesity at 21 years: a cohort study

AIMS

To determine the influence of breastfeeding on overweight and obesity, as determined by body mass index in early adulthood.

BACKGROUND

Obesity is a contemporary epidemic and linked to increased risk of later cardiovascular disease and type 2 diabetes. The success of long-term treatment is modest. Protective factors, such as potentially, and breastfeeding, are few and very important. There are uncertainties as to whether breastfeeding has a protective effect, especially in adults, or whether it is a reflection of other markers of obesity that are more linked to cardiovascular disease and diabetes risk. Some studies suggest that breastfeeding is protective in later life for cardiovascular disease and atherosclerosis.

DESIGN

Epidemiological analysis of longitudinal data set.

METHODS

We collected data about breastfeeding duration, body mass index of children at 21 years and confounding variables from an ongoing longitudinal study of a singleton birth cohort of 7223 children in Brisbane. We assessed the duration of breastfeeding at six months and prevalence of overweight and obesity at 21 years by body mass index. Adjustment for potential confounders was by multivariable multinomial logistic regression.

RESULTS

Data were available for 2553 young adults. In neither the unadjusted or adjusted analysis was longer duration of breastfeeding associated with reduction in obesity at 21 years.

CONCLUSIONS

Findings of this investigation are consistent with breastfeeding not independently affecting body mass index in young adults.

RELEVANCE TO CLINICAL PRACTICE

Breastfeeding has a range of important benefits for infants, mothers and families, although duration of breastfeeding may not play a substantial role in preventing adult onset obesity.

Risk profiles for overweight/obesity among preschoolers

BACKGROUND

The epidemic of overweight/obesity among U.S. children has led to an alarming increase in health-related consequences, including early-onset diabetes and cardiovascular disease. Recent research has identified the independent contribution of several maternal and child factors to the development of childhood overweight/obesity. Few studies, however, have examined risk profiles of childhood obesity.

AIM

This study used classification and regression tree (CART) analysis to examine the combined effect of maternal and child factors in generating risk profiles for overweight/obesity among preschoolers.

STUDY DESIGN

Data from the Early Childhood Longitudinal Study-Birth Cohort (ECLS-B) study were used. The sample was comprised of preschool children. CART and logistic regression models were built and compared.

RESULTS

Children who were overweight/obese at two years of age had an increased risk of being overweight/obese at four years of age. Children born to overweight/obese mothers were more likely to be overweight/obese by age four, even if their BMI at two years of age was normal. Children with high birth weight (> or = 4000 g.) were also more likely to be overweight/obese at age four years if they were born to mothers with a normal pregravid BMI, but were of a lower socioeconomic status. Among preschoolers whose mothers were black or white and who had a high pregravid BMI, breastfeeding duration and parity played an important role in determining their risk of being overweight/obese.

CONCLUSIONS

Classification tree analysis confirms and extends current knowledge of preschool overweight/obesity by providing preliminary risk profiles that are structured within the context of prenatal and postnatal maternal and child characteristics.

Late introduction of complementary feeding, rather than duration of breastfeeding, may protect against adult overweight

BACKGROUND

Early nutrition may affect the risk of overweight in later life.

OBJECTIVE

The objective was to explore the effect of the duration of breastfeeding (BF) and age at introduction of complementary feeding (CF) on body mass index (BMI) during childhood through adulthood.

DESIGN

The study was based on a subsample of the Copenhagen Perinatal Cohort established in 1959-1961 (n = 5068). Information on BF and available information on CF (age of introduction of "spoon-feeding," "vegetables," "egg," "meat," and "firm food") and several covariates were collected in infancy and linked with information on BMI from follow-up examinations in childhood and adulthood at age 42 y.

RESULTS

The median (10th, 90th percentiles) durations of any BF and age at introduction of spoon-feeding were 2.50 (0.23, 6.50) and 3.50 (2.00, 6.00) mo, respectively. After 1 y of age and throughout childhood and adolescence, no association between BF and BMI was found in regression models also adjusted for age at introduction of spoon-feeding and covariates. The risk of overweight at age 42 y decreased or tended to decrease with increasing age (in mo) at introduction of spoon-feeding [odds ratio (OR): 0.94; 95% CI: 0.86, 1.02], vegetables (OR: 0.90; 95% CI: 0.81, 0.98), meat (OR: 0.93; 95% CI: 0.87, 1.00), and firm food (OR: 0.92; 95% CI: 0.86, 0.98) but not egg (OR: 0.98; 95% CI: 0.91, 1.05).

CONCLUSION

The findings of this study suggest that introduction of CF at a later age (within the range of 2 to 6 mo) is protective against overweight in adulthood but do not support a protective effect of a longer duration of BF.

Do early life exposures explain associations in mid-adulthood between workplace factors and risk factors for cardiovascular disease?

BACKGROUND

Workplace factors (night work, long working hours, psychosocial work stress) have been reported to be associated with increased risk of cardiovascular disease (CVD). We investigated whether (i) workplace factors are associated with CVD risk factors independently of each other, (ii) workplace factors interact, thereby modifying associations and (iii) associations are explained by early life exposures.

METHODS

A total of 7916 employed participants in the 1958 British birth cohort underwent a clinical assessment at age 45 years. Regression analysis was used to examine associations between workplace factors and CVD risk factor levels with adjustment for early life exposures.

RESULTS

Night work was associated with adverse levels of most CVD risk factors. Working > or =48 h/week was positively associated with body mass index (BMI) and waist circumference (WC). Low job control was positively associated with glycosylated haemoglobin (HbA1c) and inflammatory factors, and inversely associated with high-density lipoprotein (HDL)-cholesterol. Low demands were positively associated with systolic blood pressure (SBP), triglycerides and inflammatory factors and inversely associated with HDL-cholesterol. Several associations were weakened when workplace factors were adjusted for each other. Night workers in low-demand jobs had higher BMI [0.78 kg/m(2); 95% confidence interval (CI) 0.35, 1.21], WC (1.49 cm; 0.45, 2.52) and SBP (1.38 mmHg; -0.04, 2.81). HDL was lower for low control plus night work (-0.04 mmol/l; -0.08, -0.01) or long hours (-0.12; -0.18, -0.69). Adjustment for early life exposures explained 30-50% of most associations, e.g. night work/low demands associations reduced by 50% for BMI and WC, and by 39% for SBP.

CONCLUSIONS

Associations between workplace factors and CVD risk factors in mid-adulthood arise in part from social and health disadvantage originating earlier in life.

Prevention of overweight and obesity in children under the age of 6 years

Although obesity was rarely observed among children 30 years ago, it is now evident among Canadian children of all ages. Currently, 15.2% of 2- to 5-year-old children are overweight, whereas 6.3% are obese. Limited data suggest that poor dietary and physical activity patterns are increasing obesity risk among these young children. Body weight and lifestyle behaviours are known to track from childhood to adulthood, thereby increasing the risk for obesity and other chronic diseases later in life. Intrauterine life, infancy, and the preschool years may all include critical periods that program the long-term regulation of energy balance, and therefore obesity-prevention strategies should be initiated in utero and continue throughout childhood and adolescence. Although single-strategy obesity-prevention initiatives have had limited success, programs that target multiple behaviours may help reduce body weight and body fat among young children. Parental involvement is key to the success of obesity-prevention programs at a young age, as parents have primary control over their children's food and activity environments. Accordingly, parental obesity is the best predictor of childhood obesity. Parents should be encouraged to teach and role model healthy lifestyle behaviours for their young children. Health professionals can also be involved in obesity prevention, as they are ideally placed to identify young children at risk for obesity. By calculating and plotting the body mass index for all children, and initiating obesity-prevention strategies in utero, health professionals can help curb the rise in overweight and obesity among young children.

Breast-feeding and overweight in Singapore school children

BACKGROUND

Studies from developed Western countries have shown inconsistent associations between breast-feeding and overweight/obesity in children and adolescents. Few data are available from Asian populations. The purpose of the present study was therefore to evaluate the association between breast-feeding and overweight/obesity in a study of 10-12-year-old children in Singapore.

METHODS

A total of 797 school children (49% girls, 76% Chinese) who participated in the Singapore Cohort Study of the Risk Factors for Myopia (SCORM) were examined. Overweight/obesity (n = 179) was defined as age-sex-specific body mass index (BMI) cut-offs corresponding to BMI of 25 kg/m(2) for overweight and 30 kg/m(2) for obesity at age 18 based on the International Obesity Task Force (IOTF) reference.

RESULTS

The prevalence of overweight/obesity was 22.5%. Overall, breast-feeding was not found to be associated with overweight/obesity. After adjusting for potential confounders, the multivariable odds ratio (95% confidence interval) of overweight/obesity was 1.14 (0.80-1.63) for ever breast-fed compared with never breast-fed, 1.00 (0.57-1.72) for breast-fed for >3 months compared to < or =3 months and 0.79 (0.47-1.34) for exclusive/mostly breast-fed compared to partly breast-fed.

CONCLUSIONS

No significant associations were detected among breast-feeding, its type, and duration with overweight/obesity in this Asian cohort of 10-12-year-old children.

Association between Infant Feeding and Early Postpartum Infant Body Composition: A Pilot Prospective Study

Research studies have produced conflicting results of the impact of breastfeeding on overweight/obesity. This study evaluated the impact of infant feeding on infant body composition. There were two groups of mother-infant pairs (exclusive breastfeeding [EBF; n = 27] and mixed feeding [MF; n = 13]) in this study. At baseline, participants were similar in their demographic characteristics except prepregnancy weight, where MF mothers tended to be heavier than their EBF counterparts (67.3 kg versus 59.9 kg; P = .034). Infant birth weight was slightly higher among the MF group than their EBF counterparts (3.5 kg versus 3.4 kg), although the differences were not statistically significant. At 3 months postpartum, mean infant FMI (4.1 kg/m(2) versus 3.8 kg/m(2)) and percent body fat (24.4% versus 23.1%) were slightly higher among EBF infants than MF infants. In terms of growth velocity, EBF infants gained weight faster than their MF counterparts, although the differences were not statistically significant. The findings from this study suggest that EBF may promote faster weight gain and increase in both fat mass index (FMI) and percent body fat in the early postpartum period in addition to the numerous health benefits enjoyed by the infant and the mother who exclusively breastfeeds her newborn.

Breastfeeding helps explain racial and socioeconomic status disparities in adolescent adiposity

OBJECTIVES

Studies suggest that breastfeeding is protective for later obesity; however, this association has not held among all racial and socioeconomic status groups. Racial and socioeconomic status differences in breastfeeding behavior have also been noted. In this study, we formally test whether breastfeeding mediates the relationship between race and socioeconomic status with adolescent adiposity.

METHODS

Data were analyzed from 739 black and white 10- to 19-year-old adolescents who participated in a large, school-based study. Parents provided information on parental education, used to measure socioeconomic status, and whether the child was breastfed as an infant. BMI was used to measure adolescent adiposity and was analyzed as a continuous measure (BMI z score) using linear regression and categorically (BMI > or = 85th and > or = 95th percentile) using logistic regression.

RESULTS

Black adolescents and those without a college-educated parent were less likely to have been breastfed for > 4 months. Race and parental education were each independent predictors of BMI z score and of having BMI > or = 85th percentile or BMI > or = 95th percentile. When added to the model, being breastfed for > 4 months was also independently associated with lower BMI z score and lower odds of having BMI > or = 85th percentile or BMI > or = 95th percentile. Inclusion of being breastfed for > 4 months resulted in a 25% decrease in racial and parental education differences in adolescent BMI z score, supporting partial mediation. CONCLUSIONS; Having been breastfed for > 4 months was associated with lower adolescent BMI z score and lower odds of having a BMI > or = 85th percentile or BMI > or = 95th percentile, independent of race or parental education. Furthermore, these analyses suggest that being breastfed for > 4 months partially explains the relationship between social disadvantage and increased adiposity. Increasing breastfeeding duration could result in lower adolescent adiposity for all racial and socioeconomic status groups and potentially minimize socioeconomic disparities in adiposity.

The development of life course epidemiology

The present paper reviews the development of life course epidemiology since its origins during the 1990s from biological programming, birth cohort research and the study of health inequalities. Methods of studying the life course are examined, including birth cohort studies, linked register datasets and epidemiological archaeology. Three models of life course epidemiology are described: critical periods, accumulation, and pathways. Their conceptual and empirical differentiation can be difficult, but it is argued that accumulation is the underlying social process driving life course trajectories, while the critical period and pathway models are distinguished by their concern with specific types of aetiological process. Among the advantages of the accumulation model are predictive power, aetiological insights, contributions to health inequality debates and social policy implications. It is emphasised that the life course approach is not opposed to, or an alternative to, a concern with cross-sectional and current effects; major social disruption can have a large and immediate impact on health. Other limitations of the life course approach include a spectrum of impact (life course effects can be strong in relation to physiology, but often are weaker in relation to behaviour and psychological reactions to everyday life) and, more speculatively, the possibility that life course effects are diluted in the older age groups where morbidity and mortality are highest. Three issues for the future of life course epidemiology are identified. Many life course data are collected retrospectively. We need to know which items of information are recalled with what degree of accuracy over how many decades; and what methods of collecting these retrospective data maximise accuracy and duration. Second, the two partners in life course research need to take more seriously each other's disciplines. Social scientists need to be more critical of such measures as self-assessed health, which lacks an aetiology and hence biological plausibility. Natural scientists need to be more critical of such concepts as socio-economic status, which lacks social plausibility because it fails to distinguish between social location and social prestige. Finally, European comparative studies can play an important part in the future development of life course epidemiology if they build on the emerging infrastructure of European comparative research.

The effect of breastfeeding on cardiorespiratory risk factors in adult life

OBJECTIVE

Nutrition in the first weeks of life may program disease risk in adulthood. We examined the influence of initial infant feeding on cardiorespiratory risk factors in adulthood.

PATIENTS AND METHODS

A total of 9377 persons born during 1 week in 1958 in England, Scotland, and Wales were followed-up periodically from birth into adulthood. Infant feeding was recorded from a parental questionnaire at 7 years old as never breastfed, breastfed partially or wholly for <1 month, or breastfed for >1 month. Height; waist circumference; hip circumference; waist/hip ratio; body mass index; blood pressure; forced expiratory volume; total, high-density, and low-density lipoprotein cholesterol; triglycerides; hemoglobin A1c; fibrinogen; fibrin D-dimer; C-reactive protein; von Willebrand factor; and tissue plasminogen activator antigen were measured at 44 to 45 years of age.

RESULTS

Breastfeeding for >1 month was associated with reduced waist circumference, waist/hip ratio, von Willebrand factor, and lower odds of obesity compared with formula feeding after adjustment for birth weight, prepregnancy maternal weight, maternal smoking during pregnancy, socioeconomic position in childhood and adulthood, region of birth, gender, and current smoking status. Infant feeding status was not associated with other cardiorespiratory risk factors after adjustment, except for lower fibrinogen and C-reactive protein levels in women.

CONCLUSIONS

The inverse associations of breastfeeding for >1 month with measures of central obesity and inflammatory markers in the current study are small and of little public health importance. Although there was no substantial long-term protective effect of breastfeeding for >1 month on other cardiorespiratory risk factors in adult life, further studies with contemporaneous data on exclusive breastfeeding are needed to confirm these findings.

A longitudinal study of infant feeding and obesity throughout life course

BACKGROUND

The Centers for Disease Control and Prevention and the US Department of Health and Human Services promote breastfeeding as a strategy for reducing childhood overweight. We evaluated the relation between infant feeding and the development of overweight and obesity throughout life course.

METHODS

We investigated the association between infant feeding and obesity among 35,526 participants in the Nurses' Health Study II who were followed prospectively from 1989 to 2001. Mothers of participants provided information by mailed questionnaires on the duration of breast- and bottle-feeding, as well as the type of milk or milk substitute in the bottle. Information on body shape at ages 5 and 10, weight at age 18, current weight between 1989 and 2001, and height was reported by the participants.

RESULTS

The duration of breastfeeding, including exclusive breastfeeding, was not related to being overweight (25< or = body mass index (BMI) <30 kg/m(2)) or obese (BMI> or =30 kg/m(2)) during adult life. Women who were exclusively breastfed for more than 6 months had a risk of 0.94 (95% confidence interval (CI) 0.83-1.07) of becoming obese as adults compared with women who were not breastfed. Exclusive breastfeeding for more than 6 months was associated with leaner body shape at age 5 (odds ratio (OR)=0.81; 95% CI 0.65-1.01 for the highest vs the lowest category of body shape) compared to women who were not breastfed or breastfed for less than 1 week, but this association did not persist during adolescence or adulthood.

CONCLUSIONS

We did not find that having been breastfed was associated with women's likelihood of becoming overweight or obese throughout life course. Although breastfeeding promotes the health of mother and child, it is unlikely to play an important role in controlling the obesity epidemic.

Early determinants of overweight at 4.5 years in a population-based longitudinal study

OBJECTIVES

The roots of the obesity epidemic need to be traced back as early in life as possible in order to develop effective means for preventing obesity and its health consequences in the future. The aim of this paper is to examine a broad range of factors that may simultaneously contribute to childhood overweight in a population-based cohort of children followed from birth to 4.5 years, to determine which factors exert the most influence in early life.

DESIGN

The analyses were performed using data from the Quebec Longitudinal Study of Child Development 1998-2002 (QLSCD).

SUBJECTS

The study follows a representative sample (n=2103) of children born in 1998 in the Canadian province of Quebec.

MEASURE

Measured height and weight were available for 1550 children aged 4.5 years. At 4.5 years, BMI was analyzed using the US CDC sex- and age-specific growth charts. In order to study children at their highest weights at various ages, odds ratios were presented for high birth weight, weight-for-stature at or above the 95th percentile at 5 months, and BMI at or above the 95th percentile at 4.5 years. Monthly weight gain between birth and five months has been analyzed. Children were also evaluated by the Z-score obtained from the standardized weight divided by height. Factors potentially related to children's weight include sex, gestational age and birth rank, breastfeeding, mothers' smoking status during pregnancy, family type at child's birth, and family income before pregnancy and when the children were 5 months and 4.5 years old. Other parental factors such as height and overweight/obesity (based on BMI) and other maternal factors (age, education, immigrant status) were also part of the analysis.

RESULTS

Being in the highest quintiles of weight gain between birth and 5 months, as well as maternal smoking during pregnancy, almost double the odds of being overweight at 4.5 years. Parental overweight or obesity also increased the odds of being overweight at this age, as well as being raised in middle-income or in poor families. A greater proportion of children born to nonsmoking mothers with higher weights (more than 4000 g) were overweight at 4.5 years, the percentage being greatest for those in the highest weight-gain categories from birth to 5 months. The pattern was different for children born to smoking mothers. The greatest proportion of 4.5-year-old overweight children was seen for children born in the normal weight-range category (3000-4000 g) who were in the highest quintiles of weight gain from birth to 5 months, and for children with high birth weights (more than 4000 g) who were in the lowest quintiles of birth-to-5-months weight gain. Children who were overweight at 4.5 years and who had been born to smoking mothers started life with a birth weight around that for the population means, but they gained more weight in the first 5 months of life than did the children of nonsmoking mothers.

CONCLUSION

This study indicates that behavioral and social factors exert critical influences on the onset of childhood overweight in preschool years. From a population-health perspective, interventions aimed at preventing childhood obesity would do well to target smoking pregnant women, as well as nonsmoking pregnant women at risk for giving birth to high-birth-weight children, paying particular attention to rapid weight gain in the first months of life.

Food behaviors and other strategies to prevent and treat pediatric overweight

OBJECTIVE

To summarize the evidence for the following six strategies to prevent or treat overweight among children: promoting breastfeeding, promoting physical activity, reducing TV/video viewing, increasing fruit and vegetable consumption, reducing sugar-sweetened drink consumption, and reducing portion sizes.

METHODS

Summarization of the relevant literature including review articles, relevant newly published work, the Institute of Medicine's Report on Preventing Childhood Obesity and the Surgeon General's Call to Action to Prevent and Decrease Overweight and Obesity, 2001. This is not a comprehensive review.

RESULTS

Evidence for the association between each strategy and overweight varies. For breastfeeding, physical activity, and TV viewing, there are large review studies. Breastfed children may have a small reduction in risk for overweight. Participation in physical activity may reduce the risk of overweight among school-aged children and adolescents. For preschool- and school-aged children, reducing TV viewing time may reduce their risk of overweight, but most studies report small significant associations. Evidence for an association between each dietary factor and overweight is limited and inconclusive. The biggest gaps in evidence are for the effectiveness of interventions using these strategies. The reviewed interventions based on increasing physical activity (n=7) were effective. Two randomized trials suggest that reducing TV viewing reduces overweight. No intervention studies were found that examined the effectiveness of changing fruit and vegetable consumption, sugar-sweetened drink consumption, or portion sizes. Further clarification of the effect of breastfeeding on obesity is needed.

CONCLUSIONS

These six strategies are reasonable ways to attempt prevention or treatment of overweight in children. Strength of the evidence varies by strategy. The key finding is that more applied research is needed to determine the effectiveness of these and other strategies.

Breastfeeding and obesity at 14 years: a cohort study

AIM

To determine the influence of breastfeeding on overweight and obesity in early adolescence.

METHODS

Data about breastfeeding duration, BMI of children at 14 years, and confounding variables, were collected from an ongoing longitudinal study of a birth cohort of 7776 children in Brisbane. Prevalence of overweight and obesity at 14 years was assessed according to duration of breastfeeding, with logistic regression being used to adjust for the influence of confounders.

RESULTS

Data were available for 3698 children, and those not included were significantly different in age, educational level, income, race, birthweight, and small-for-gestational-age status. Breastfeeding for longer than six months was protective of obesity (OR 0.6, 95% CI 0.4, 0.96) though not of overweight. When confounding variables were considered the effect size diminished and lost statistical significance OR 0.8 (95% CI 0.5, 1.3). Breastfeeding for less than 6 months had no effect on either obesity or overweight though a trend was found for increased prevalence of overweight at 14 years with shorter periods of breastfeeding.

CONCLUSION

This investigation contributes to the gathering body of evidence that breastfeeding for longer than 6 months has a modest protective effect against obesity in adolescence.

Protective effect of breastfeeding against obesity in childhood. Can a meta-analysis of observational studies help to validate the hypothesis?

The relationship between breast-feeding and childhood obesity is of great interest. Since 2000, sixteen studies have been published with conflicting data regarding the potential protective effect of breast-feeding on childhood obesity. A narrative review of Dewey in 2003 suggested a protective effect of breast-feeding, but an editorial in the British Medical Journal later that year cited two more recent studies without such an effect and stated there was inconclusive evidence A recent meta-analysis, however, has suggested a small, but significant, protective effect of breast-feeding. This paper summarizes this meta-analysis and discusses the strengths and limitations of the meta-analysis approach.

The effect of breastfeeding on mean body mass index throughout life: a quantitative review of published and unpublished observational evidence

BACKGROUND

Evidence from observational studies has suggested that breastfeeding may reduce the prevalence of obesity in later life.

OBJECTIVE

The objective was to examine whether initial breastfeeding is related to lower mean body mass index (BMI; in kg/m(2)) throughout life.

DESIGN

The study was a systematic review of published studies investigating the association between infant feeding and a measure of obesity or adiposity in later life, which was supplemented with data from unpublished sources. Analyses were based on the mean differences in BMI between those subjects who were initially breastfed and those who were formula-fed (expressed as breastfed minus bottle-fed), which were pooled by using fixed-effects models throughout.

RESULTS

From 70 eligible studies, 36 mean differences in BMI (from 355 301 subjects) between those breastfed and those formula-fed (reported as exclusive feeding in 20 studies) were obtained. Breastfeeding was associated with a slightly lower mean BMI than was formula feeding (-0.04; 95% CI: -0.05, -0.02). The mean difference in BMIs appeared larger in 15 small studies of <1000 subjects (-0.19; 95% CI: -0.31, -0.08) and smaller in larger studies of >or=1000 subjects (-0.03; 95% CI: -0.05, -0.02). An Egger test was statistically significant (P = 0.002). Adjustment for socioeconomic status, maternal smoking in pregnancy, and maternal BMI in 11 studies abolished the effect (-0.10; 95% CI: -0.14, -0.06 before adjustment; -0.01; 95% CI: -0.05, 0.03 after adjustment).

CONCLUSIONS

Mean BMI is lower among breastfed subjects. However, the difference is small and is likely to be strongly influenced by publication bias and confounding factors. Promotion of breastfeeding, although important for other reasons, is not likely to reduce mean BMI.

Smoking during pregnancy and bulimia nervosa in offspring

Because smoking during pregnancy is implicated in influencing appetite and impulse control in offspring, the aim of this study was to establish if it is associated with bulimia nervosa in offspring. Bulimia was identified at age 30 years among 4046 females, born 5-11 April, 1970. After adjustment for potential confounding factors including body mass index (BMI) and maternal psychiatric morbidity, smoking during pregnancy was associated with bulimia in offspring by age 30 years. Compared with non-smoking mothers, the adjusted odds ratios (95% confidence intervals) for bulimia in offspring were 0.74 (0.25-2.21) for those who gave up before pregnancy, 3.04 (1.16-7.95) for giving up during pregnancy and 2.64 (1.47-4.74) for smoking throughout pregnancy. Smoking during pregnancy was not associated with anorexia nervosa in offspring. Neither BMI nor variation between childhood and adult BMI explain the association. If the association of smoking during pregnancy with bulimia in offspring is causal, then it may operate through compromised central nervous system development and its influence on impulse or appetite control. The increased risk associated with mothers who gave up smoking during pregnancy emphasizes the importance of smoking cessation prior to conception.

How much protein is safe?

BACKGROUND

Since breastfeeding and human milk seem to prevent, while high dietary proteins in the first 2 y of life seem to promote, later overweight, questions have been raised on the safe levels of proteins in the early years. How much protein (as a percentage of total calorie intake) is safe?

METHODS

Revision of available data on the protein content of human milk, protein intake in the first 2 y of life and their association with body mass development.

RESULTS

We should move from the figure of 7-8% in the 4-month exclusively breastfed infants up to the maximum acceptable levels of 14% in 12-24-month-old infants. When protein supply represents less than 6% and energy is limited, fully breastfed infants are likely to enter a status of negative nutrient balance. Over the limit of 14% energy from proteins in the 6-24 months period, some mechanisms may begin to operate, leading young children towards an early adiposity rebound and overweight development, beyond any genetic predisposition. Preliminary data seem to indicate a causal role for whole cow's milk proteins.

CONCLUSION

We suggest maintaining breastfeeding as long as possible, and, in case human milk is insufficient, to introduce infant formulas, appropriate for age, up to 18-24 months, in order to keep protein intakes in the safe range of 8-12% within a diet adequate in energy and balanced as far as macronutrients.