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

Combined Influence of Gestational Diabetes and Gestational Weight Gain on Exclusive Breastfeeding

Background: Over half of pregnant women in the United States do not meet the recommended gestational weight gain (GWG). In addition, the prevalence of gestational diabetes mellitus (GDM) is increasing. We examined the combined influence of GDM and GWG on breastfeeding practices on exclusive breastfeeding during the neonatal period and at 3 months postpartum. Materials and Methods: A cross-sectional study was performed on 173,603 women from the pregnancy risk assessment monitoring system, 2009-2015. Descriptive statistics and multivariable logistic regression modeling were performed. Results: The prevalence of GDM was 9.5%. Only 30.7% of women had weight gain within the Institute of Medicine (IOM) recommended guidelines. Approximately 21.7% and 10.3% of the participants exclusively breastfed their infants during the neonatal period and at 3 months postpartum, respectively. After adjusting for potential confounders, there was a significant multiplicative interaction between GWG and GDM on exclusive breastfeeding during the neonatal period and at 3 months postpartum. Among women with normal and excessive GWG, the odds of exclusively breastfeeding during the neonatal period were lower for women with GDM compared with women without GDM (odds ratio, 95% confidence interval: 0.74, 0.64-0.85 and 0.75, 0.66-0.85, respectively). Similarly, among women with normal and excessive GWG, the odds of exclusively breastfeeding at 3 months postpartum were lower for women with GDM compared to women without GDM (0.67, 0.55-0.81 and 0.71, 0.60-0.85, respectively). Conclusion: With the increasing prevalence of GDM and weight gain outside the IOM guidelines, it is critical to identify populations at risk and to promote exclusive breastfeeding practices.

The Pattern of Complementary Foods in American Infants and Children Aged 0⁻5 Years Old-A Cross-Sectional Analysis of Data from the NHANES 2011⁻2014

Proper nutrition early in life can influence children’s present and future health. While several authoritative sources provide eating/food recommendations, only a few studies have assessed whether these recommendations are followed. The goal of this paper was to examine food and nutrient intakes on any given day during infancy and early childhood among various ethnicities. Twenty-four-hour dietary recall data of 0–5 years-old children (n = 2431) from the National Health and Nutrition Examination Survey (NHANES) 2011–2014 was used to estimate intakes of nutrients and food groups and prevalence of inadequate intake. Data was analyzed separately for various age groups and ethnicities, and differences in means by age and or race/ethnicity were determined by t-tests with p < 0.05 as significant. The results indicate that intakes of all food groups were expectedly low at 0–11 months, increased with age, and were influenced by race/ethnicity. Mixed dish consumption, which also increased with age, made substantial contributions to children’s food group intakes. However, there was a substantial percentage of the population among all age and race/ethnic groups who did not consume the recommended amounts for each food group and had inadequate intakes of key nutrients, such as calcium, vitamin D, and vitamin E. Non-Hispanic black children consumed less dairy and more protein foods, and a significantly greater proportion of these children had inadequate intakes of calcium and vitamin D compared to their peers. In conclusion, the results from this study suggest that a substantial population of American infants and children from 0 to five years of age did not meet food group recommendations and had inadequate intakes of key nutrients such as calcium, vitamin D, and vitamin E from foods.

Maternal breastfeeding, early introduction of non-breast milk, and excess weight in preschoolers

Objective:

Investigate associations between excess weight in preschool children, breastfeeding duration and age of non-breast milk introduction.

Methods:

Cross-sectional study of a representative sample of 817 preschool children, aged 2-4 years, attending municipal day care centers in the city of Taubaté. The weight and height of children were measured in the day care centers in 2009, 2010 and 2011. The body mass index z-score (BMIz) was calculated and children were classified as risk of overweight (BMIz≥1 to<2) or excess weight (BMIz≥2). Data analysis was carried out by comparison of proportions, coefficient of correlation and multivariate linear regression.

Results:

The prevalence of risk of overweight was 18.9% and of excess weight (overweight or obesity) was 9.3%. The median duration of breastfeeding and age of introduction of non-breast milk was 6 months. The child's BMIz showed direct correlation with birth weight (r=0.154; p<0.001) and maternal body mass index (BMI) (r=0.113; p=0.002). The correlation was inverse with the total duration of breastfeeding (r=−0.099; p=0.006) and age at non-breast milk introduction (r=−0.112; p=0.002). There was no correlation between the child's BMIz with birth length, duration of exclusive breastfeeding and mother's age.

Conclusions:

The earlier the introduction of non-breast milk, the higher the correlation with excess weight at preschool age.

Association between History of Gestational Diabetes and Exclusive Breastfeeding at Hospital Discharge

BACKGROUND

Exclusive breastfeeding is recommended in the first 6 months of life, especially for infants born to women with a history of gestational diabetes mellitus (GDM). Yet, women with a history of GDM face challenges with exclusive breastfeeding in the early postpartum period, a critical period for setting up longer term breastfeeding success. Minimal research has been published on associated risk factors for not exclusively breastfeeding.

OBJECTIVE

The purpose of this study was to examine the association between GDM and exclusive breastfeeding at hospital discharge.

METHODS

We conducted a cross-sectional analysis including 2038 women who participated in the population-based Infant Feeding Practices Study II between May 2005 and June 2007.

RESULTS

Gestational diabetes mellitus prevalence was 5.8%. The crude prevalence of exclusive breastfeeding at hospital discharge was 62.2% among women with GDM compared to 75.4% of women without GDM (P < .01). After adjusting for sociodemographic, behavioral, and anthropometric factors, the odds of exclusive breastfeeding were lower among women with GDM compared to women without diabetes (odds ratio = 0.59; 95% confidence interval, 0.39-0.92). Furthermore, women who had gestational weight gain (GWG) below the Institute of Medicine guidelines had lower odds of exclusive breastfeeding compared to women who had normal GWG (odds ratio = 0.62; 95% confidence interval, 0.45-0.85).

CONCLUSION

Women with GDM history and women with inadequate GWG may need additional education to promote exclusive breastfeeding during maternal hospital stay. It is important for health care providers to assess both factors when providing education on exclusive breastfeeding and to support these women's breastfeeding efforts in the early postpartum period to maximize potential for longer term breastfeeding success.

Maternal breastfeeding, early introduction of non-breast milk, and excess weight in preschoolers

OBJECTIVE

Investigate associations between excess weight in preschool children, breastfeeding duration and age of non-breast milk introduction.

METHODS

Cross-sectional study of a representative sample of 817 preschool children, aged 2 to 4 years, attending municipal day care centers in the city of Taubaté. The weight and height of children were measured in the day care centers in 2009, 2010 and 2011. The body mass index z-score (BMIz) was calculated and children were classified as risk of overweight (BMIz≥1 to<2) or excess weight (BMIz≥2). Data analysis was carried out by comparison of proportions, coefficient of correlation and multivariate linear regression.

RESULTS

The prevalence of risk of overweight was 18.9% and of excess weight (overweight or obesity) was 9.3%. The median duration of breastfeeding and age of introduction of non-breast milk was 6 months. The child's BMIz showed direct correlation with birth weight (r=0.154; p<0.001) and maternal Body Mass Index (BMI) (r=0.113; p=0.002). The correlation was inverse with the total duration of breastfeeding (r=-0.099; p=0.006) and age at non-breast milk introduction (r=-0.112; p=0.002). There was no correlation between the child's BMIz with birth length, duration of exclusive breastfeeding and mother's age.

CONCLUSIONS

The earlier the introduction of non-breast milk, the higher the correlation with excess weight at preschool age.

Dietary protein intake is associated with body mass index and weight up to 5 y of age in a prospective cohort of twins

BACKGROUND

Few large epidemiologic studies have investigated the role of postweaning protein intake in excess weight and adiposity of young children, despite children in the United Kingdom consistently consuming protein in excess of their physiologic requirements.

OBJECTIVE

We investigated whether a higher proportion of protein intake from energy beyond weaning is associated with greater weight gain, higher body mass index (BMI), and risk of overweight or obesity in children up to 5 y of age.

DESIGN

Participants were 2154 twins from the Gemini cohort. Dietary intake was collected by using a 3-d diet diary when the children had a mean age of 21 mo. Weight and height were collected every 3 mo, from birth to 5 y. Longitudinal models investigated associations of protein intake with BMI, weight, and height, with adjustment for age at diet diary, sex, total energy intake, birth weight/length, and rate of prior growth and clustering within families. Logistic regression investigated protein intake in relation to the odds of overweight or obesity at 3 and 5 y of age.

RESULTS

A total of 2154 children had a mean ± SD of 5.7 ± 3.2 weight and height measurements up to 5 y. Total energy from protein was associated with higher BMI (β = 0.043; 95% CI: 0.011, 0.075) and weight (β = 0.052; 95% CI: 0.031, 0.074) but not height (β = 0.088; 95% CI: -0.038, 0.213) between 21 mo and 5 y. Substituting percentage energy from fat or carbohydrate for percentage energy from protein was associated with decreases in BMI and weight. Protein intake was associated with a trend in increased odds of overweight or obesity at 3 y (OR = 1.10; 95% CI 0.99, 1.22, P = 0.075), but the effect was not statistically significant at 5 y.

CONCLUSION

A higher proportion of energy from protein during the complementary feeding stage is associated with greater increases in weight and BMI in early childhood in this large cohort of United Kingdom children.

Early factors leading to later obesity: interactions of the microbiome, epigenome, and nutrition

Obesity is a major public health problem in the United States and many other countries. Childhood obesity rates have risen extensively over the last several decades with the numbers continuing to rise. Obese and overweight children are at high risk of becoming overweight adolescents and adults. The causes are multifactorial and are affected by various genetic, behavioral, and environmental factors. This review aims to discuss a previously under-recognized antecedent of obesity and related chronic metabolic diseases such as heart disease and diabetes. Specifically, we highlight the relationship of the microbial ecology of the gastrointestinal tract during early development and the consequent effects on metabolism, epigenetics, and inflammatory responses that can subsequently result in metabolic syndrome. Although studies in this area are just beginning, this area of research is rapidly expanding and may lead to early life interventions that may have significant impacts in the prevention of obesity.

Breastfeeding, early nutrition, and adult body fat

OBJECTIVE

To examine the association between breastfeeding and adult body fatness, adjusting for nutritional intake in early childhood.

STUDY DESIGN

Nutritional intakes of 73 healthy infants born in 1984 who participated in the 2-decade-long Longitudinal Study of Nutrition and Growth in Children (Etude Longitudinale Alimentation Nutrition Croissance des Enfants [ELANCE]) were estimated at age 10 months and again at age 2 years. Breastfeeding was defined as any breastfeeding, including partial breastfeeding, regardless of duration. At age 20 years, weight, height, subscapular skinfold thickness (SF), and fat mass (assessed via bioelectrical impedance analysis) were measured.

RESULTS

In this sample, 64% of the children had been breastfed. In linear regression models adjusted for mother's body mass index and father's profession, breastfeeding was not associated with any of the body fat measurements at 20 years (all P > .05). After adding nutritional intake variables (total energy and % energy from nutrients) to the models, breastfeeding became significantly associated with lower SF at 20 years. In particular, breastfed subjects had significantly lower % SF at 20 years after adjustment for energy and % fat intakes at 2 years of age, (β = -28.25% SF; 95% CI, -50.28% to -6.21%; P = .013) or when adjusting for energy and % carbohydrates at 2 years of age (β = -28.27% SF; 95% CI, -50.64% to -5.90%; P = .014).

CONCLUSION

Breastfeeding was not associated with adult body fatness taking into account the usual confounding factors. However, after also adjusting for nutritional intake covariates, a protective effect of breastfeeding emerged. Early nutrition needs to be taken into account when examining the long-term health effects of breastfeeding.

Socioeconomic patterning of childhood overweight status in Europe

There is growing evidence of social disparities in overweight among European children. This paper examines whether there is an association between socioeconomic inequality and prevalence of child overweight in European countries, and if socioeconomic disparities in child overweight are increasing. We analyse cross-country comparisons of household inequality and child overweight prevalence in Europe and review within-country variations over time of childhood overweight by social grouping, drawn from a review of the literature. Data from 22 European countries suggest that greater inequality in household income is positively associated with both self-reported and measured child overweight prevalence. Moreover, seven studies from four countries reported on the influence of socioeconomic factors on the distribution of child overweight over time. Four out of seven reported widening social disparities in childhood overweight, a fifth found statistically significant disparities only in a small sub-group, one found non-statistically significant disparities, and a lack of social gradient was reported in the last study. Where there is evidence of a widening social gradient in child overweight, it is likely that the changes in lifestyles and dietary habits involved in the increase in the prevalence of overweight have had a less favourable impact in low socio-economic status groups than in the rest of the population. More profound structural changes, based on population-wide social and environmental interventions are needed to halt the increasing social gradient in child overweight in current and future generations.

Introduction of solid food to young infants

Timing of the first introduction of solid food during infancy may have potential effects on life-long health. To understand the characteristics that are associated with the timing of infants’ initial exposure to solid foods. The 2000 National Survey of Early Childhood Health (NSECH) was a nationally representative telephone survey of 2,068 parents of children aged 4–35 months, which profiled content and quality of health care for young children. African-American and Latino families were over-sampled. Analyses in this report include bivariate tests and logistic regressions. 62% of parents reported introducing solids to their child between 4–6 months of age. African-American mothers (OR = 0.5 [0.3, 0.9]), English-speaking Latino mothers (OR = 0.4 [0.2, 0.7]), White mothers with more than high school education (OR = 0.5 [0.2, 1.0]), and mothers who breastfed for 4 months or longer (OR = 0.4 [0.3, 0.7]) were less likely to introduce solids early. Most parents (92%) of children 4–9 months of age reported that their pediatric provider had discussed introduction of solids with them since the child’s birth, and provider discussion of feeding was not associated with the timing of introduction of solids. Although most parents recall discussing the introduction of solid foods with their child’s physician, several subgroups of mothers introduce solid foods earlier than the AAP recommendation of 4–6 months. More effective discussion of solid food introduction linked to counseling and support of breastfeeding by the primary health care provider may reduce early introduction of solids.

Determinants of rapid weight gain during infancy: baseline results from the NOURISH randomised controlled trial

Background

Rapid weight gain in infancy is an important predictor of obesity in later childhood. Our aim was to determine which modifiable variables are associated with rapid weight gain in early life.

Methods

Subjects were healthy infants enrolled in NOURISH, a randomised, controlled trial evaluating an intervention to promote positive early feeding practices. This analysis used the birth and baseline data for NOURISH. Birthweight was collected from hospital records and infants were also weighed at baseline assessment when they were aged 4-7 months and before randomisation. Infant feeding practices and demographic variables were collected from the mother using a self administered questionnaire. Rapid weight gain was defined as an increase in weight-for-age Z-score (using WHO standards) above 0.67 SD from birth to baseline assessment, which is interpreted clinically as crossing centile lines on a growth chart. Variables associated with rapid weight gain were evaluated using a multivariable logistic regression model.

Results

Complete data were available for 612 infants (88% of the total sample recruited) with a mean (SD) age of 4.3 (1.0) months at baseline assessment. After adjusting for mother's age, smoking in pregnancy, BMI, and education and infant birthweight, age, gender and introduction of solid foods, the only two modifiable factors associated with rapid weight gain to attain statistical significance were formula feeding [OR = 1.72 (95%CI 1.01-2.94), P = 0.047] and feeding on schedule [OR = 2.29 (95%CI 1.14-4.61), P = 0.020]. Male gender and lower birthweight were non-modifiable factors associated with rapid weight gain.

Conclusions

This analysis supports the contention that there is an association between formula feeding, feeding to schedule and weight gain in the first months of life. Mechanisms may include the actual content of formula milk (e.g. higher protein intake) or differences in feeding styles, such as feeding to schedule, which increase the risk of overfeeding.

Trial Registration

Australian Clinical Trials Registry ACTRN12608000056392

Babies fed breastmilk by breast versus by bottle: a pilot study evaluating early growth patterns

BACKGROUND

Numerous studies have documented short- and long-term differences in growth and body composition based on whether an infant is breastfed or formula-fed. However, little is known about whether these differences result from the substance consumed (breastmilk vs. formula) or from the delivery method (breast vs. bottle). This prospective pilot study compared the growth and body composition patterns of 19 predominantly breastfed/nursing infants (NG) and 18 infants fed significant quantities of breastmilk by bottle (BG) during the first 6 months of life.

METHODS

Infants were measured in a laboratory setting each month by trained staff. Growth measures (length, weight, and head circumference) were compared to World Health Organization growth standards. Body composition, including relative fat mass (%FM), was measured using an air-displacement plethysmography system (Pea Pod(®), Life Measurement, Inc., Concord, CA).

RESULTS

With the exception of small differences in length and weight scaled for length (body mass index and weight-for-length z-score) present at birth and continuing for the first 1-2 months of life, NG and BG infants were similar in weight, weight-for-age z-scores, head circumference, fat mass, and %FM. However, BG infants were three times more likely to exceed the 85(th) percentile for weight velocity during the 4-6-month age interval than NG infants (33% vs. 10%, respectively), but this did not reach statistical significance in this sample size (p = 0.12).

CONCLUSIONS

This pilot study suggests the delivery method (breast vs. bottle) for breastmilk may not dramatically affect growth for the first 4 months of life; however, future research with larger samples will be needed to carefully evaluate longer-term growth patterns in infants fed breastmilk by bottle.

Incidence of diabetes mellitus at postpartum six to twelve months following the diagnosis of gestational diabetes mellitus

OBJECTIVE

The aim of this study was to research the rates of diabetes mellitus (DM) and the risk factors that may play a role in the prediction of this condition by evaluating patients with the diagnosis of gestational diabetes mellitus (GDM) at the 6(th)-12(th) postpartum months.

MATERIAL AND METHOD

Among 109 cases who had been invited to the hospital for oral glucose tolerance test (OGTT) at the 6(th)-12(th) postpartum months, 84 cases (77%) were enrolled in the study. To the 78 patients that were found to be appropriate according to the study criteria, 75 gr OGTT was administered. Patients who had new pregnancies during the period of postpartum screening, and those with previously diagnosed DM were excluded from the study.

RESULTS

While the results of 23 cases (29.5%) included in the study were normal, 27 cases (34.6%) were diagnosed with DM and 28 cases (35.9%) were diagnosed as having an impaired glucose tolerance and/or impaired fasting glucose (IGT/IFG). Among patients diagnosed with DM, the history of DM in the first degree relatives (n=21, 77.8%, p=0.018), body mass index before pregnancy (mean=30.1±4.4, p=0.009) and insulin requirement for the treatment of GDM (n=25, 92.6%, p<0.05) were determined at higher rates. In the logistic regression analysis, multiparity (OR=2) and insulin requirement during pregnancy (OR: 7.27) were found to be the predictive factors in the development of postpartum DM.

DISCUSSION

In this study, the determination of high rates of DM development in the postpartum period after GDM demonstrates the necessity of augmentation in efforts to increase the screening rates after delivery and to increase the patients' acknowledgement of this topic.

The obesity epidemic

Obesity has reached epidemic proportions in the United States, with 35.1% of adults being classified as obese. Obesity affects every segment of the US population and continues to increase steadily, especially in children. Obesity increases the risk for many other chronic diseases, including diabetes mellitus, cardiovascular disease, and nonalcoholic fatty liver disease, and decreases overall quality of life. The current US generation may have a shorter life expectancy than their parents if the obesity epidemic is not controlled, and there is no indication that the prevalence of obesity is decreasing. Because of the complexity of obesity, it is likely to be one of the most difficult public health issues our society has faced.

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.

Period-specific growth, overweight and modification by breastfeeding in the GINI and LISA birth cohorts up to age 6 years

Children's weight/growth development is age-specific and may be influenced by breastfeeding. We therefore assessed velocities of weight, length, body-mass-index and overweight/obesity development from birth up to age 6 years overall and in relation to breastfeeding. The method of this study is based on pooled data of the birth-cohorts GINI-plus and LISA-plus and follows 7,643 healthy full-term neonates in four study-centers in Germany. Up to nine anthropometric measurements are available. Overweight/obesity is percentile-defined according to WHO-Child-Growth-Standards. Fully-breastfed is defined as breastfed for at least 4 months. Piecewise-linear-random-coefficient-models were applied to assess growth trajectories and velocities between 0-3, 3-6, 6-12, 12-24 and beyond 24th months. Velocities for weight-, length- and BMI-development are highest in the first 3 months after birth and diminish, with differing pace, in the periods that follow. For overweight and obesity, peak-velocities are estimated in periods 6-12 and 3-6 months. The difference in the velocity of weight gain for breastfed vs. other children is -18 g/month in the first 3 month, -93 g/month between month 3 and 6, -14 g/month between month 6 and 12 and -3 g/month beyond the 24th month. Velocities in length are not different between breastfed and non-breastfed children. Over time, a slightly lower risk (difference < 2%) of being overweight was estimated for breastfed children, after adjustment for study-center, socio-economic-status and maternal smoking in pregnancy. Infants fully-breastfed gain less weight, but grow equally in length in the first 12 months of life versus mixed or formula-fed children. The protective effect of breastfeeding on becoming overweight is related to its weight-velocity-modifying-effect in early infancy.

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.

Adiponectin: an intriguing hormone for paediatricians

Adiponectin, a protein hormone produced by adipocytes, is also found in breast milk, which in turn is implicated in childhood obesity prevention. Although a biological role for adiponectin has not been firmly established, clinical and experimental research indicates that it regulates lipid and glucose metabolism, affects foetal development, and exerts anti-inflammatory and antiatherogenic effects.

CONCLUSION

This review demonstrates an emerging interest of paediatric research on adiponectin. A better understanding of adiponectin's bioactivity might clarify whether breast milk indeed prevents childhood obesity.

Early life programming of obesity and metabolic disease

It is becoming increasingly apparent that conditions experienced in early life play an important role in the long-term health of individuals. Alterations in development due to impaired, excessive or imbalanced growth, both in utero and during critical periods of relative plasticity beyond birth, can lead to the permanent programming of physiological systems. The regulation of energy balance is one area that is receiving particular attention, as rates of obesity and associated metabolic and cardiovascular disease continue to rise. Over recent decades, much progress has been made toward understanding the way in which metabolic tissues and physiological systems develop, and the impact of early life events and nutrition on these processes. It is apparent within human populations that some individuals are better able to maintain an appropriate body weight in the face of an obesogenic environment. Animal models have been widely used for the investigation of differential susceptibility to diet-induced obesity (DIO) and impaired energy balance regulation, and are shedding light on key pathways that may be involved. Alterations in pathways mediating energy homeostasis, outlined below, are likely candidates for programming effects following disturbed growth in early life.

Session 1: Feeding and infant development breast-feeding and immune function

The newborn receives, via the placenta, maternal IgG antibodies against the microbes present in its surroundings, but such antibodies have a pro-inflammatory action, initiating the complement system and phagocytes. Although the host defence mechanisms of the neonate that involve inflammatory reactivity are somewhat inefficient, this defence system can still have catabolic effects. Breast-feeding compensates for this relative inefficiency of host defence in the neonate by providing considerable amounts of secretory IgA antibodies directed particularly against the microbial flora of the mother and her environment. These antibodies bind the microbes that are appearing on the infant's mucosal membranes, preventing activation of the pro-inflammatory defence. The major milk protein lactoferrin can destroy microbes and reduce inflammatory responses. The non-absorbed milk oligosaccharides block attachment of microbes to the infant's mucosae, preventing infections. The milk may contain anti-secretory factor, which is anti-inflammatory, preventing mastitis in mothers and diarrhoea in infants. Numerous additional factors in the milk are of unknown function, although IL-7 is linked to the larger size of the thymus and the enhanced development of intestinal Tgammadelta lymphocytes in breast-fed compared with non-breast-fed infants. Several additional components in the milk may help to explain why breast-feeding can reduce infant mortality, protecting against neonatal septicaemia and meningitis. It is therefore important to start breast-feeding immediately. Protection is also apparent against diarrhoea, respiratory infections and otitis media. There may be protection against urinary tract infections and necrotizing enterocolitis, and possibly also against allergy and certain other immunological diseases, and tumours. In conclusion, breast-feeding provides a very broad multifactorial anti-inflammatory defence for the infant.