Considerable advances have occurred in recent years in the scientific knowledge of the benefits of breastfeeding, the mechanisms underlying these benefits, and in the clinical management of breastfeeding. This policy statement on breastfeeding replaces the 1997 policy statement of the American Academy of Pediatrics and reflects this newer knowledge and the supporting publications. The benefits of breastfeeding for the infant, the mother, and the community are summarized, and recommendations to guide the pediatrician and other health care professionals in assisting mothers in the initiation and maintenance of breastfeeding for healthy term infants and high-risk infants are presented. The policy statement delineates various ways in which pediatricians can promote, protect, and support breastfeeding not only in their individual practices but also in the hospital, medical school, community, and nation.

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Breastfeeding and the Use of Human Milk

Importance Approximately 80% of US adults and adolescents are insufficiently active. Physical activity fosters normal growth and development and can make people feel, function, and sleep better and reduce risk of many chronic diseases. Objective To summarize key guidelines in thePhysical Activity Guidelines for Americans, 2nd edition (PAG). Process and Evidence Synthesis The 2018 Physical Activity Guidelines Advisory Committee conducted a systematic review of the science supporting physical activity and health. The committee addressed 38 questions and 104 subquestions and graded the evidence based on consistency and quality of the research. Evidence graded as strong or moderate was the basis of the key guidelines. The Department of Health and Human Services (HHS) based the PAG on the2018 Physical Activity Guidelines Advisory Committee Scientific Report. Recommendations The PAG provides information and guidance on the types and amounts of physical activity to improve a variety of health outcomes for multiple population groups. Preschool-aged children (3 through 5 years) should be physically active throughout the day to enhance growth and development. Children and adolescents aged 6 through 17 years should do 60 minutes or more of moderate-to-vigorous physical activity daily. Adults should do at least 150 minutes to 300 minutes a week of moderate-intensity, or 75 minutes to 150 minutes a week of vigorous-intensity aerobic physical activity, or an equivalent combination of moderate- and vigorous-intensity aerobic activity. They should also do muscle-strengthening activities on 2 or more days a week. Older adults should do multicomponent physical activity that includes balance training as well as aerobic and muscle-strengthening activities. Pregnant and postpartum women should do at least 150 minutes of moderate-intensity aerobic activity a week. Adults with chronic conditions or disabilities, who are able, should follow the key guidelines for adults and do both aerobic and muscle-strengthening activities. Recommendations emphasize that moving more and sitting less will benefit nearly everyone. Individuals performing the least physical activity benefit most by even modest increases in moderate-to-vigorous physical activity. Additional benefits occur with more physical activity. Both aerobic and muscle-strengthening physical activity are beneficial. Conclusions and Relevance ThePhysical Activity Guidelines for Americans, 2nd edition, provides information and guidance on the types and amounts of physical activity that provide substantial health benefits. Health professionals and policy makers should facilitate awareness of the guidelines and promote the health benefits of physical activity and support efforts to implement programs, practices, and policies to facilitate increased physical activity and to improve the health of the US population.

https://jamanetwork.com/journals/jama/articlepdf/2712935/jama_Piercy_2018_sc_180005.pdf

The Physical Activity Guidelines for Americans

To revise 1998 recommendations on childhood obesity, an Expert Committee, comprised of representatives from 15 professional organizations, appointed experienced scientists and clinicians to 3 writing groups to review the literature and recommend approaches to prevention, assessment, and treatment. Because effective strategies remain poorly defined, the writing groups used both available evidence and expert opinion to develop the recommendations. Primary care providers should universally assess children for obesity risk to improve early identification of elevated BMI, medical risks, and unhealthy eating and physical activity habits. Providers can provide obesity prevention messages for most children and suggest weight control interventions for those with excess weight. The writing groups also recommend changing office systems so that they support efforts to address the problem. BMI should be calculated and plotted at least annually, and the classification should be integrated with other information such as growth pattern, familial obesity, and medical risks to assess the child’s obesity risk. For prevention, the recommendations include both specific eating and physical activity behaviors, which are likely to promote maintenance of healthy weight, but also the use of patient-centered counseling techniques such as motivational interviewing, which helps families identify their own motivation for making change. For assessment, the recommendations include methods to screen for current medical conditions and for future risks, and methods to assess diet and physical activity behaviors. For treatment, the recommendations propose 4 stages of obesity care; the first is brief counseling that can be delivered in a health care office, and subsequent stages require more time and resources. The appropriateness of higher stages is influenced by a patient’s age and degree of excess weight. These recommendations recognize the importance of social and environmental change to reduce the obesity epidemic but also identify ways healthcare providers and health care systems can be part of broader efforts.

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Expert Committee Recommendations Regarding the Prevention, Assessment, and Treatment of Child and Adolescent Overweight and Obesity: Summary Report

Ten per cent of the world’s school-aged children are estimated to be carrying excess body fat (Fig. 1), with an increased risk for developing chronic disease. Of these overweight children, a quarter are obese, with a significant likelihood of some having multiple risk factors for type 2 diabetes, heart disease and a variety of other co-morbidities before or during early adulthood. The prevalence of overweight is dramatically higher in economically developed regions, but is rising significantly in most parts of the world. In many countries the problem of childhood obesity is worsening at a dramatic rate. Surveys during the 1990s show that in Brazil and the USA, an additional 0.5% of the entire child population became overweight each year. In Canada, Australia and parts of Europe the rates were higher, with an additional 1% of all children becoming overweight each year. The burden upon the health services cannot yet be estimated. Although childhood obesity brings a number of additional problems in its train – hyperinsulinaemia, poor glucose tolerance and a raised risk of type 2 diabetes, hypertension, sleep apnoea, social exclusion and depression – the greatest health problems will be seen in the next generation of adults as the present childhood obesity epidemic passes through to adulthood. Greatly increased rates of heart disease, diabetes, certain cancers, gall bladder disease, osteoarthritis, endocrine disorders and other obesityrelated conditions will be found in young adult populations, and their need for medical treatment may last for their remaining life-times. The costs to the health services, the losses to society and the burdens carried by the individuals involved will be great. The present report has been written to focus attention on the issue and to urge policy-makers to consider taking action before it is too late. Specifically, the report:

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1467-789X.2004.00133.x

Obesity in children and young people: a crisis in public health.

The purpose was to: 1) perform a systematic review of studies examining the relation between physical activity, fitness, and health in school-aged children and youth, and 2) make recommendations based on the findings. The systematic review was limited to 7 health indicators: high blood cholesterol, high blood pressure, the metabolic syndrome, obesity, low bone density, depression, and injuries. Literature searches were conducted using predefined keywords in 6 key databases. A total of 11,088 potential papers were identified. The abstracts and full-text articles of potentially relevant papers were screened to determine eligibility. Data was abstracted for 113 outcomes from the 86 eligible papers. The evidence was graded for each health outcome using established criteria based on the quantity and quality of studies and strength of effect. The volume, intensity, and type of physical activity were considered. Physical activity was associated with numerous health benefits. The dose-response relations observed in observational studies indicate that the more physical activity, the greater the health benefit. Results from experimental studies indicate that even modest amounts of physical activity can have health benefits in high-risk youngsters (e.g., obese). To achieve substantive health benefits, the physical activity should be of at least a moderate intensity. Vigorous intensity activities may provide even greater benefit. Aerobic-based activities had the greatest health benefit, other than for bone health, in which case high-impact weight bearing activities were required. The following recommendations were made: 1) Children and youth 5-17 years of age should accumulate an average of at least 60 minutes per day and up to several hours of at least moderate intensity physical activity. Some of the health benefits can be achieved through an average of 30 minutes per day. [Level 2, Grade A]. 2) More vigorous intensity activities should be incorporated or added when possible, including activities that strengthen muscle and bone [Level 3, Grade B]. 3) Aerobic activities should make up the majority of the physical activity. Muscle and bone strengthening activities should be incorporated on at least 3 days of the week [Level 2, Grade A].

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Systematic review of the health benefits of physical activity and fitness in school-aged children and youth

EDITOR,-Borato Viana et al report evidence that malnutrition is an adverse prognostic factor in childhood acute lymphoblastic leukaemia (ALL), suggest that the effect may apply even to moderately undernourished children, and discuss some possible mechanisms.I While the relevance of severe malnutrition to the developed world may seem limited, our own evidence2 indicates that relatively mild undernutrition (weight for height SD score <-0 5) had adverse prognostic significance for children treated for ALL in Glasgow on the UKALL-X protocol. We would also like to add two possible mechanisms which may be worthy of investigation: impairment of immune function by undernutrition and variability in body composition between patients producing variation in drug pharmacokinetics.3 There are now three studies which indicate the need for further research on the relevance of nutritional status to outcome in ALL, and on the possible mechanisms.' 2 4

https://adc.bmj.com/content/archdischild/72/1/98.1.full.pdf

Malnutrition as a prognosis factor in lymphoblastic leukemia: a multivariate analysis.

Early life risk factors for childhood obesity

Objective: To explore trends in prevalence and socioeconomic inequalities in underweight and obesity in 5-year-old schoolchildren in Scotland between 2011/2012 and 2017/2018.

Design: A population-based, repeated cross-sectional study.

Setting: Local authority primary schools in Scotland.

Participants: 373 189 5-year-old schoolchildren in Scotland between 2011/2012 and 2017/2018.

Methodology: Trends in prevalence and inequalities in underweight and obesity were examined across seven school years (2011/2012–2017/2018) for 373 189 5-year-old schoolchildren in Scotland. Body mass index SD scores were calculated, and epidemiological cut-offs relative to the UK 1990 references categorised underweight and obesity. Slope/relative indices of inequality (SII/RII) were calculated for underweight and obesity by school year using the area-based Scottish Index of Multiple Deprivation.

Results: The prevalence of obesity rose slightly overall during the study period (9.8% in 2011/2012; 10.1% in 2017/2018). However, this masked a widening of inequalities, with children from the most deprived areas experiencing a greater risk of obesity in 2017/2018 than in 2011/2012 (risk ratio=1.14, 95% CI 1.04 to 1.25) compared with an unchanged risk in children from the least deprived areas (risk ratio=0.95, 95% CI 0.82 to 1.11). SII and RII indicate widening inequalities for obesity, with RII rising from 1.95 (95% CI 1.71 to 2.22) in 2011/2012 to 2.22 (95% CI 1.93 to 2.56) in 2017/2018. The prevalence of underweight was consistently low (compared with the UK 1990 references) and remained unchanged over the study period (1.2% in 2011/2012; 1.1% in 2017/2018), with no consistent evidence of social patterning over time.

Conclusions: Inequalities in obesity in schoolchildren in Scotland are large and have widened from 2011, despite only a slight rise in overall prevalence. In contrast there has been little change in underweight prevalence or inequalities during the study period. Extra resources for policy implementation and measures which do not widen inequalities and focus on reaching the most deprived children are required to tackle the high prevalence and growing inequalities in childhood obesity in Scotland.

https://bmjopen.bmj.com/content/bmjopen/11/3/e042023.full.pdf

Trends in socioeconomic inequalities in underweight and obesity in 5-year-old children, 2011-2018: a population-based, repeated cross-sectional study.

The present study aimed to determine the validity of simple epidemiological and clinical methods for the assessment of body fatness in preschool children. In 89 children (42 boys, 47 girls; mean age 4.1 SD 1.3y) measures of body fatness were made using total body water (TBW), dual energy x-ray absorptiometry (DXA), air displacement plethysmography (BODPOD) and skinfold thickness. Methods were compared by Bland–Altman analysis using TBW as the reference method, and by paired comparisons and rank order correlations. Bias for DXA was +1.8% body fat percentage units (limits of agreement +15.5% to -11.9%), bias for BODPOD was -3.5% (limits of agreement +18.9% to -5.9%) and bias for skinfolds using the Slaughter equations was -6.5% (limits of agreement +10.0% to –23.1%). Significant rank order correlations with TBW measures of fatness were obtained for DXA estimates of fatness (r=0.54, P=0.01), but not for estimates of fat by skinfold thickness (r=0.20, P=0.2) or BODPOD (r=0.25, P=0.1). Differences between both DXA and BODPOD and the reference TBW estimates of body fatness were not significant (P=0.06 and P=0.1 respectively); however, the difference in estimated body fatness between skinfold thickness and TBW was significant (P<0.001). Estimates of body fatness in preschool children were inaccurate at the level of the individual child using all the methods, but DXA might provide unbiased estimates and a means of making relative assessments of body fatness.

Validation of simple epidemiological or clinical methods for the measurement of body composition in young children.

Vitamin D insufficiency may be common among elite athletes, but prevalence is unclear, and some potentially important risk factors are uncertain. The present study aimed to (a) estimate the prevalence of vitamin D insufficiency in elite athletes, and (b) examine differences in prevalence between the sexes, and between adults and adolescents, from recent studies which used a contemporary definition of insufficiency.Four databases (Web of Science, SPORTDiscus, PubMed, and Sports Medicine and Education Index) were searched for studies in elite athletes. Literature selection, data extraction, and risk of bias assessment were conducted independently by two researchers. Vitamin D insufficiency was defined as 25(OH)D < 50 nmol/L. Meta-analysis was conducted, using R software x64 4.0.2, to provide estimates of prevalence of insufficiency for adults and adolescents, and to examine between-sex differences in risk of insufficiency.From the initial 943 literature search hits, 51 studies were eligible with 5456 participants, 33 studies in adults (12/33 in winter and spring), 15 studies in adolescents (6/15 in winter and spring) and 3 studies with age of study participants not given. Prevalence of vitamin D insufficiency from meta-analysis was 30% (95% CI 22-39%) in adults and prevalence was higher, though not significantly so, at 39% (95% CI 25-55%) in adolescents. Differences in the prevalence of insufficiency between the sexes for the eight studies which provided within-study comparisons was not significant (RR = 1.0; 95% CI 0.79-1.26). Evidence quality was moderate.Prevalence of vitamin D insufficiency (≤ 50 nmol/L) in elite athletes is high, suggesting a need for greater attention to prevention and treatment. Prevalence estimates in the present study are conservative due to a relative lack of studies in winter. While there was no evidence of higher risk among women than men in the present study, there was less evidence on women. 

/pdf/prevalence-and-novel-risk-factors-for-vitamin-d-1jq0o2hb.pdf

John J. Reilly

Papers

Malnutrition as a prognosis factor in lymphoblastic leukemia: a multivariate analysis.

Early life risk factors for childhood obesity

Trends in socioeconomic inequalities in underweight and obesity in 5-year-old children, 2011-2018: a population-based, repeated cross-sectional study.

Validation of simple epidemiological or clinical methods for the measurement of body composition in young children.

Prevalence and novel risk factors for vitamin D insufficiency in elite athletes: systematic review and meta-analysis