David Freedman

David Freedman

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210
Publications
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28,310
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Publications

Publications (210)
Article
Objective: There have been conflicting reports concerning weight gain among adults during the COVID-19 epidemic. Although early studies reported large weight increases, several of these analyses were based on convenience samples or self-reported information. The objective of the current study is to examine the pandemic-related weight increase asso...
Article
Background: Weight control programs for children monitor BMI changes using BMI z-scores that adjust BMI for the sex and age of the child. It is, however, uncertain if BMIz is the best metric for assessing BMI change. Objective: To identify which of 6 BMI metrics is optimal for assessing change. We considered a metric to be optimal if its short-t...
Article
Objective This study compared the importance of age at adiposity rebound versus childhood BMI to subsequent BMI levels in a longitudinal analysis. Methods From the electronic health records of 4.35 million children, a total of 12,228 children were selected who were examined at least once each year between ages 2 and 7 years and reexamined after ag...
Article
What is already known about this topic? The COVID-19 pandemic led to school closures, disrupted routines, increased stress, and less opportunity for physical activity and proper nutrition, leading to weight gain among children and adolescents. What is added by this report? Among a cohort of 432,302 persons aged 2–19 years, the rate of body mass ind...
Article
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Background: Infants and young children with high weight-for-length are at increased risk for obesity in later life. This study describes prevalence of high weight-for-length and examines changes during 2010-2018 among 11,366,755 infants and young children 3-23 months of age in the Special Supplemental Nutrition Program for Women, Infants, and Child...
Article
Obesity* is a recognized risk factor for severe COVID-19 (1,2), possibly related to chronic inflammation that disrupts immune and thrombogenic responses to pathogens (3) as well as to impaired lung function from excess weight (4). Obesity is a common metabolic disease, affecting 42.4% of U.S. adults (5), and is a risk factor for other chronic disea...
Article
Objective The current CDC BMI z-scores are inaccurate for BMIs ≥ 97th percentile. We, therefore, considered 5 alternatives that can be used across the entire BMI distribution: modified BMIz, %CDC95th percentile, extended BMIz, %median, and %median adjusted for the dispersion of BMIs. Study design We illustrate the behavior of the metrics among chi...
Article
Objective: The beginning of postinfancy increase in BMI has been termed the adiposity rebound, and an early rebound increases the risk for obesity in adolescence and adulthood. We examined whether the relation of the age at BMI rebound (agerebound) to subsequent BMI is independent of childhood BMI. Design: From the electronic health records of 2.8...
Article
Objective The Mind, Exercise, Nutrition, Do It! 7–13 (MEND 7–13) program was adapted in 2016 by five Denver Health federally qualified health centers (DH FQHC) into MEND+, integrating clinician medical visits into the curriculum and tracking health measures within an electronic health record (EHR). We examined trajectories of body mass index (BMI,...
Article
Background: The 2000 CDC growth charts are based on national data collected between 1963 and 1994 and include a set of selected percentiles between the 3rd and 97th and LMS parameters that can be used to obtain other percentiles and associated z-scores. Obesity is defined as a sex- and age-specific body mass index (BMI) at or above the 95th percen...
Article
Public health surveillance of obesity describes changes over time and identifies subgroups at risk of obesity-related consequences. We analyzed trends, stratified by race and Hispanic origin, in high weight for length, obesity, and severe obesity in the US from 1999 to 2018.
Article
Objective Several cross‐sectional studies have shown that height in childhood is correlated with BMI and with body fatness, and two longitudinal studies have reported that childhood height is associated with adult BMI. This study explored this longitudinal association in an electronic health record database of 2.8 million children. Methods Childre...
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Background and objective: As obesity among children and adolescents is associated with major health risks, including the persistence of obesity into adulthood, there has been interest in targeting prevention efforts at children and adolescent. The longitudinal tracking of BMI and obesity, as well as the effects of initial age and duration of follo...
Article
Obesity negatively affects children's health because of its associations with cardiovascular disease risk factors, type 2 diabetes, asthma, fatty liver disease, victimization stemming from social stigma and bullying, and poor mental health (e.g., anxiety and depression) (1). Children who have overweight or obesity in early childhood are approximate...
Article
In Reply We agree with Drs Stefan and Schulze that there are limitations of BMI as a surrogate of adiposity in our study of the prevalence of obesity among children aged 2 through 4 years enrolled in WIC.
Article
Body mass index z-score (BMIz) based on the CDC growth charts is widely used, but it is inaccurate above the 97th percentile. We explored the performance of alternative metrics based on the absolute distance or % distance of a child’s BMI from the median BMI for sex and age. We used longitudinal data from 5628 children who were first examined < 12...
Article
Prevalence of childhood obesity is high in the United States, especially among children from lower-income families.¹ Among children aged 2 through 4 years enrolled in the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC), obesity prevalence increased between 2000 and 2010 but declined through 2014.² The decline was stati...
Article
Importance Differences in obesity by sex, age group, race and Hispanic origin among US adults have been reported, but differences by urbanization level have been less studied. Objectives To provide estimates of obesity by demographic characteristics and urbanization level and to examine trends in obesity prevalence by urbanization level. Design,...
Article
Importance Differences in childhood obesity by demographics and urbanization have been reported. Objective To present data on obesity and severe obesity among US youth by demographics and urbanization and to investigate trends by urbanization. Design, Setting, and Participants Measured weight and height among youth aged 2 to 19 years in the 2001-...
Article
Objective Although the tracking of BMI levels from childhood to adulthood has been examined, there is little information on the within‐person variability of BMI. Methods Longitudinal data from 11,591 schoolchildren, 3,096 of whom were reexamined as adults, were used to explore the tracking and variability of BMI levels. This article focuses on cha...
Article
Obesity prevalence has been increasing since the 1980s among adults, but among youth, prevalence plateaued between 2005-2006 and 2013-2014.¹,2 We analyzed trends in obesity prevalence among US youth and adults between 2007-2008 and 2015-2016 in order to determine recent changes.
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Obesity prevalence varies by income and education level, although patterns might differ among adults and youths (1-3). Previous analyses of national data showed that the prevalence of childhood obesity by income and education of household head varied across race/Hispanic origin groups (4). CDC analyzed 2011-2014 data from the National Health and Nu...
Article
Background: BMI z-scores (BMIz) based on the Centers for Disease Control and Prevention (CDC) growth charts among children do not accurately characterise BMI levels among children with very high BMIs. These limitations may be particularly relevant in longitudinal and intervention studies, as the large changes in the L (normality) and S (dispersion)...
Article
Objective: To examine the associations among several body mass index (BMI) metrics (z-scores, percent of the 95th percentile (%BMIp95) and BMI minus 95th percentile (ΔBMIp95) as calculated in the growth charts from the Centers for Disease Control and Prevention (CDC). It is known that the widely used BMI z-scores (BMIz) and percentiles calculated...
Article
Objective: Although the Centers for Disease Control and Prevention (CDC) growth charts are widely used, BMI-for-age z-Scores (BMIz) are known to be uninformative above the 97th percentile. This study compared the relations of BMIz and other BMI metrics (%BMIp95 , percent of 95th percentile, and ΔBMIp95 , BMI minus 95th percentile) to circumference...
Article
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Objectives: To describe the prevalence and secular trends of high weight-for-length among infants (ages, 3-23 months) in the biennial US Department of Agriculture Women, Infants, and Children Program and Participants Characteristic (WIC-PC) Survey from 2000 through 2014 (n = 16 927 120). Methods: Weight-for-length was considered to be "high" if...
Article
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Childhood obesity is associated with negative health consequences in childhood (1) that continue into adulthood (2), putting adults at risk for type 2 diabetes, cardiovascular disease, and certain cancers (1). Obesity disproportionately affects children from low-income families (3). Through a collaboration with the United States Department of Agric...
Article
Background: Although the prevalence of a body mass index [BMI (in kg/m(2))] ≥30 has tripled among US adults since the 1960s, BMI is only moderately correlated with body fatness. Because skinfolds can more accurately estimate body fatness than can BMI, it is possible that skinfolds could be useful in monitoring secular trends in body fatness. Obje...
Article
Objective: This study assessed the prevalence and consistency of high values of weight, height, and BMI considered to be biologically implausible (BIV) using cut points proposed by WHO among 8.8 million low-income children (13.7 million observations). Methods: Cross-sectional and longitudinal analyses were performed among 2- to 4-year-olds who w...
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Background: Although the estimation of body fatness by Slaughter skinfold thickness equations (PBFSlaughter) has been widely used, the accuracy of this method is uncertain. We have previously examined the interrelationships among the body mass index (BMI), PBFSlaughter, percent body fat from dual energy X-ray absorptiometry (PBFDXA) and CVD risk f...
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Background and objectives: Children with Down syndrome (DS) have lower birth weights and grow more slowly than children without DS. Advances in and increased access to medical care have improved the health and well-being of individuals with DS; however, it is unknown whether their growth has also improved. Our objective was to develop new growth c...
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Background: Several studies have shown that the waist circumference of children and adolescents has increased over the last 25 years. However, given the strong correlation between waist circumference and BMI, it is uncertain if the secular trends in waist circumference are independent of those in BMI. Methods: We analyzed data from 6- to 19-year...
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Background: The WHO cutoffs to classify biologically implausible values (BIVs) for weight, height, and weight-for-height in children and adolescents are widely used in data cleaning. Objectives: We assess 1) the prevalence of these BIVs, 2) whether they were consistent with information on waist circumference, arm circumference, and leg lengths,...
Article
Several studies showed that the waist circumference of US adults has increased over the past 25 y. However, because of the high correlation between waist circumference and body mass index (BMI; in kg/m(2)) (r ∼ 0.9), it is uncertain if these trends in waist circumference exceed those expected on the basis of BMI changes over this time period. We as...
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Recent national data suggest there were improvements in serum lipid concentrations among US children and adolescents between 1988 and 2010 but an increase in or stable blood pressure (BP) during a similar period. To describe the prevalence of and trends in dyslipidemia and adverse BP among US children and adolescents. The National Health and Nutrit...
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Background: The sagittal abdominal diameter (SAD) measured in supine position is an alternative adiposity indicator that estimates the quantity of dysfunctional adipose tissue in the visceral depot. However, supine SAD's distribution and its association with health risk at the population level are unknown. Here we describe standardized measurement...
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Objective: To examine whether sugar-sweetened beverage (SSB) intake during infancy predicts obesity at age 6 years. Methods: We included 1189 children who participated in the Infant Feeding Practices Study II in 2005-2007 and were followed up at 6 years in 2012. Children's weight and height were measured by mothers. Obesity was defined as gender...
Article
The relative importance of the fourth (K4) and fifth (K5) Korotkoff phases as the indicator of diastolic blood pressure (DBP) levels among children remains uncertain. In a sample of 11,525 youth aged 5-17, we examined interexaminer differences in these 2 phases and the relation of theses 2 phases to adult blood pressure levels and hypertension. The...
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Obesity is a major public health problem affecting adults and children in the United States. Since 1960, the prevalence of adult obesity in the United States has nearly tripled, from 13% in 1960-1962 to 36% during 2009-2010. Since 1970, the prevalence of obesity has more than tripled among children, from 5% in 1971-1974 to 17% in 2009-2010. Althoug...
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Although estimation of percentage body fat with the Slaughter skinfold-thickness equations (PBFSlaughter) is widely used, the accuracy of this method has not been well studied. The objective was to determine the accuracy of the Slaughter skinfold-thickness equations. We compared agreement between PBFSlaughter and derived from dual-energy X-ray abso...
Article
A recent, cross-sectional analysis of adults found that the hip circumference divided by height1.5 minus 18 (the body adiposity index, BAI) was strongly correlated (r = 0.79) with percent body fat determined by dual energy X-ray absorptiometry. The BAI was proposed as a more accurate index of body fatness than BMI. We examined whether BAI was more...
Article
Objective: To examine the accuracies of body mass index (BMI) and skinfold thicknesses in classifying the body fatness of 7365 8- to 19-year-old subjects in a national sample. Study design: We used percent body fat determined by dual-energy x-ray absorptiometry (PBFDXA) between 1999 and 2004. Categories of PBFDXA and the skinfold sum (triceps pl...
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The prevalence of obesity among children and adolescents increased by almost threefold from the 1970s to 2000. We examined whether these secular changes in BMI were accompanied by increases in blood pressure levels. A total of 24,092 examinations were conducted among 11,478 children and adolescents (aged 5-17 years) from 1974 to 1993 in the Bogalus...
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Because of its strong association (r 0·85) with percentage of body fat determined by dual-energy X-ray absorptiometry, hip circumference divided by height1·5 (the body adiposity index) has recently been proposed as an index of body fatness among adults. We examined whether this proposed index was more strongly associated with skinfold thicknesses a...
Article
Based on cross-sectional analyses, it was suggested that hip circumference divided by height(1.5) minus 18 (the body adiposity index, BAI), could directly estimate percent body fat without the need for further correction for sex or age. We compared the prediction of percent body fat, as assessed by dual-energy x-ray absorptiometry (PBF(DXA)), by BA...
Article
This chapter focuses on the classification of high levels of BMI and body fatness, the relation of BMI to body fatness among children, and the ability of a high BMI to identify children with excess body fatness. Many of the results are based on published data from the Pediatric Rosetta Study, but several are from unpublished analyses of this large...
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The high prevalence of obesity (defined by body mass index) among children and adolescents in the United States and elsewhere has prompted increased attention to body fat in childhood and adolescence. This report provides smoothed estimates of major percentiles of percentage body fat for boys and girls aged 8-19 years in the United States. Percenta...
Conference Paper
Researchers, public health practitioners, and legislators are looking to large-scale fitness testing in schools as one approach to address and monitor childhood obesity. Some states and cities already use these data to conduct surveillance of student fitness levels and body mass index (BMI). Data quality must be a top priority if fitness testing in...
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ABSTRACT: No recent national studies have provided incidence data for obesity, nor have they examined the association between incidence and selected risk factors. The purpose of this study is to examine the incidence of obesity (body mass index [BMI] ≥ 30.0 kg/m2) and extreme obesity (BMI ≥ 40.0 kg/m2) among US adults and to determine variations ac...
Chapter
Findings from the Bogalusa Heart Study have furthered the understanding of the natural history of obesity, as well as its short- and long-term consequences. Although the limitations of BMI (kg/m2) as an indicator of body fatness are widely recognized, this simple index appears to be able to identify metabolic risk as accurately as do methods that a...
Article
The prevalence of obesity in the United States has increased substantially since the 1960s. From 1976--1980 to 2007--2008, obesity prevalence increased from 15% to 34% among adults and from 5% to 17% among children and adolescents. Substantial differences exist in obesity prevalence among racial/ethnic groups, and these differences vary by sex and...
Article
Recent secular trends have resulted in large numbers of very overweight children who are at increased risk for type 2 diabetes mellitus and for various coronary heart disease risk factors, including adverse levels of lipids, insulin, and blood pressure. Furthermore, severe overweight in childhood is associated with risk factor clustering and with t...
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The cutoffs from the Centers for Disease Control and Prevention (CDC) growth charts and from the Cooper Institute (FitnessGram) are widely used to identify children who have a high body mass index (BMI). We compared the abilities of these 2 systems to identify children who have adverse lipid concentrations and blood pressure measurements and the re...
Article
A 2008 report from the American Academy of Pediatrics recommended both population and individual approaches (including pharmacologic interventions) for adolescents who had low-density lipoprotein (LDL) cholesterol levels above various cutoff points (130, 160, and 190 mg/dL). However, the tracking and variability of these very high levels have not b...
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Although adverse levels of cardiovascular disease risk factors are related to skinfold thicknesses and BMI among adults, the relative strengths of these associations are unknown. We examine whether the triceps and subscapular skinfold thicknesses are more strongly related to adult levels of lipids, fasting insulin and blood pressure than BMI. Cross...
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To examine 35-year trends in the prevalence of overweight and obesity among children and adolescents from Bogalusa, Louisiana. Height and weight were measured for 11653 children and adolescents between 5 and 17 years of age in 8 cross-sectional surveys. The Bogalusa Heart Study contributed data from 1973-1994, and routine school screening provided...
Data
Morbid Obesity as a Risk Factor for Hospitalization and Death due to 2009 Pandemic Influenza A(H1N1) Disease. (0.11 MB DOC)
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Background: Severe illness due to 2009 pandemic A(H1N1) infection has been reported among persons who are obese or morbidly obese. We assessed whether obesity is a risk factor for hospitalization and death due to 2009 pandemic influenza A(H1N1), independent of chronic medical conditions considered by the Advisory Committee on Immunization Practice...
Article
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Body mass index (BMI)-for-age has been recommended as a screening test for excess adiposity in children and adolescents. We quantified the performance of standard categories of BMI-for-age relative to the population prevalence of high adiposity in children and adolescents overall and by race-ethnic group in a nationally representative US population...
Article
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To examine the ability of various body mass index (BMI)-for-age categories, including the Centers for Disease Control and Prevention's 85th to 94th percentiles, to correctly classify the body fatness of children and adolescents. Cross-sectional. The New York Obesity Research Center at St Luke's-Roosevelt Hospital from 1995 to 2000. Healthy 5- to 18...
Article
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The 2000 Centers for Disease Control and Prevention (CDC) growth charts included lambda-mu-sigma (LMS) parameters intended to calculate smoothed percentiles from only the 3rd to the 97th percentile. The objective was to evaluate different approaches to describing more extreme values of body mass index (BMI)-for-age by using simple functions of the...
Article
Although the prevalence of childhood obesity, as assessed by BMI (kg/m(2)), has tripled over the last 3 decades, this index is a measure of excess weight rather than excess body fatness. In this review we focus on the relation of BMI to body fatness and health risks, particularly on the ability of BMI for age >or=95th Centers for Disease Control an...
Article
Although the body mass index (BMI, kg m(-2)) is widely used as a measure of adiposity, it is a measure of excess weight, rather than excess body fat. It has been suggested that skinfold thicknesses be measured among overweight children to confirm the presence of excess adiposity. The present study examined the additional information provided by ski...
Article
The purpose of this study was to examine ethnic differences in adiposity as measured by sum of skinfolds (SKF) and waist circumference (WC) in children and adolescents, after statistical adjustment for the BMI and age. A cross sectional sample of 3,218 (55% white, 49% male) children and adolescents aged 5-18 years who participated in the Bogalusa H...