Laura Kettel Khan

The relation of childhood BMI to adult adiposity: the Bogalusa Heart Study.

Objective. Although many studies have found that childhood levels of body mass index (BMI; kg/m2) are associated with adult levels, it has been reported that childhood BMI is not associated with adult adiposity. We further examined these longitudinal associations. Design. Cohort study based on examinations between 1973 and 1996. Setting. Bogalusa, Louisiana. Participants. Children (2610; ages 2-17 years old) who were followed to ages 18 to 37 years; the mean follow-up was 17.6 years. Main Outcome Measures. BMI-for-age and triceps skinfold thickness (SF) were measured in childhood. Subscapular and triceps SFs were measured among adults, and the mean SF was used as an adiposity index. Adult obesity was defined as a BMI ≥ 30 kg/m2 and adult overfat as a mean SF in the upper (gender-specific) quartile. Results. Childhood levels of both BMI and triceps SF were associated with adult levels of BMI and adiposity. The magnitude of these longitudinal associations increased with childhood age, but the BMI levels of even the youngest (ages 2-5 years) children were moderately associated (r = 0.33-0.41) with adult adiposity. Overweight (BMI-for-age ≥ 95th centile) 2- to 5-year-olds were >4 times as likely to become overfat adults (15 of 23 [65%]), as were children with a BMI < 50th centile (30 of 201 [15%]). Even after accounting for the triceps SF of children, BMI-for-age provided additional information on adult adiposity. Conclusions. Childhood BMI is associated with adult adiposity, but it is possible that the magnitude of this association depends on the relative fatness of children.

Racial and Ethnic Differences in Secular Trends for Childhood BMI, Weight, and Height

Objectives: The prevalence of childhood overweight in the United States has markedly increased over the last 30 years. We examined differences in the secular trends for BMI, weight, and height among white, black, and Mexican‐American children.

Overweight and obesity in preschool children from developing countries

OBJECTIVES: To estimate levels and trends in overweight and obesity in preschool children from developing countries; to study how overweight varies by the educational level of the mother, by urban or rural residence, and by gender; to investigate how these relationships are related to the gross national product (GNP).DESIGN: 71 national nutrition surveys since 1986 from 50 countries were used.SUBJECTS: 150,482 children 12 to 60 months from the most recent survey from each country were the primary sample.MEASUREMENTS: Overweight and obesity were defined as weight-for-height (>1 or >2 s.d., respectively) of the WHO/NCHS reference curves. Stunting was <−2 s.d. of the same reference. Urban was as defined in each of the surveys and higher education was defined as at least one year of secondary schooling or higher.RESULTS: 32 of 50 countries had a prevalence of obesity below 2.3%, the value in the reference population. The prevalences of overweight and obesity were lowest in Asia and in Sub-Saharan Africa. In 17 countries with serial data, no consistent regional trends could be detected. Overweight was more common in urban areas, in children of mothers with higher education, and in girls; these relationships did not differ by GNP but GNP was related negatively to stunting and positively to overweight.CONCLUSIONS: Obesity does not appear to be a public health problem among preschool children in Asia and Sub-Saharan Africa. In a number of countries in Latin America and the Caribbean, the Middle East and North Africa, and the region of Central Eastern Europe/Commonwealth of Independent States, levels are as high as in the United States.

Inter-relationships among childhood BMI, childhood height, and adult obesity: the Bogalusa Heart Study

OBJECTIVE: Although the body mass index (BMI, mass index, kg/m2) is widely used as a surrogate measure of adiposity, it is moderately associated (r∼0.3) with height among children. We examined whether the resulting preferential classification of taller children as overweight is appropriate.DESIGN: Cross-sectional analyses of children (ages, 3–17 y) examined the relation of height to adiposity (as assessed by BMI and skinfold thicknesses) and fasting levels of insulin. Longitudinal analyses examined the relation of childhood height and weight–height indices to adult (mean age, 25 y) levels of adiposity and fasting insulin.SUBJECTS: Children (n=11 406) and adults (n=2911) who had participated in the Bogalusa Heart Study.MEASUREMENTS: We constructed three weight–height indices: BMI, W/H 3, and W/H p. The triceps and subscapular skinfolds, as well as fasting levels of insulin, were also measured.RESULTS: The classification of children as overweight (BMI-for-age ⩾95th percentile) varied markedly by height, with a 10-fold difference in the prevalence of overweight across quintiles of height between the ages of 3 and 10 y. Childhood height, however, was also related to skinfold thicknesses and insulin levels, and all associations were modified in a similar manner by age. Furthermore, childhood height was related to adult adiposity, and of the three childhood weight–height indices, BMI showed the strongest associations with adult adiposity.CONCLUSIONS: Because BMI reflects the positive association between height and adiposity among children, it is a better weight–height index than is either W/H 3 or W/H p.

The relation of menarcheal age to obesity in childhood and adulthood: the Bogalusa heart study

BackgroundSeveral studies have shown that girls who undergo menarche at a relatively young age tend to be more obese as adults. However, because childhood (pre-menarcheal) levels of weight and height are associated with an earlier menarche, the increased prevalence of adult obesity among early maturers may largely reflect the persistence of childhood obesity into adulthood.MethodsWe examined these interrelationships among 1179 girls (65% white, 35% black) who were examined as children (mean age, 9 y), adolescents, and adults (mean age, 26 y) in the Bogalusa Heart Study.ResultsBoth white and black women who reported that they underwent menarche before age 12 y had, on average, higher adult levels of weight (+10 kg), body mass index (BMI, +4 kg/m2) and skinfold thicknesses (+6 mm) than did women who underwent menarche after age 13.5 y. However, relatively fat children tended to undergo menarche earlier than did thinner children, with each standard deviation increase in pre-menarcheal BMI increasing the odds of early menarche (<12 y) by approximately 2-fold. Stratified and regression analyses indicated that (1) adult obesity was more strongly associated with childhood obesity than with menarcheal age, and (2) about 60% to 75% of the apparent effect of menarcheal age was due to the influence of childhood obesity on both menarcheal age and adult obesity.ConclusionsAlthough additional longitudinal studies are needed, it is likely that the importance of early menarche in adult obesity has been overestimated. Most of apparent influence of menarcheal age on adult obesity is attributable to the association of childhood obesity with both menarcheal age and adult obesity.

Acculturation, socioeconomic status, and obesity in Mexican Americans, Cuban Americans, and Puerto Ricans

OBJECTIVES: This study examined the relationship between acculturation and obesity in United States (US) Hispanics, controlling for socioeconomic status (SES). METHODS: The sample included 3141 Mexican American, 828 Cuban American, and 1211 Puerto Rican adults 18–74 y of age in the 1982–84 Hispanic Health and Nutrition Examination Survey (HHANES). Acculturation was measured by language preference and generation; SES by income and education; and obesity by body mass index (BMI). RESULTS: Mean and standard deviations of BMI (kg/m2) were 25.9±4.4, 26.0±4.2, and 25.5±4.3 in men of Mexican American, Cuban American, and Puerto Rican origin, respectively. For women, the corresponding values were 26.6±5.8, 25.9±5.0, and 26.2±5.9. Linear regression models of BMI which included acculturation, income, education, and other covariates were carried out. Income and education were not associated consistently with BMI. Acculturation, but only among Mexican Americans, was associated with BMI. Specifically, greater preference for English was associated with reduced BMI among women (P<0.01). Also, men and women of the second (P<0.001 in both sexes) and third (P<0.01 in men and P<0.001 in women) generation had greater BMIs. Relative to the first generation, the increase in BMI units was 1.15±0.34 in men and 1.76±0.39 in women in the second generation and 0.83±0.31 in men and 1.83±0.37 in women of the third generation. CONCLUSIONS: BMI was not associated with SES, an unexpected finding since the relationship is generally negative in women from developed countries. The relationship between BMI and acculturation was weak and conditional. BMI in Mexican Americans appeared to be somewhat more sensitive to the process of acculturation than among Cubans or Puerto Ricans.

A conceptual model of the food and nutrition system

The food system is a widely used concept, but few systematic frameworks model the full scope and structure of the food and nutrition system. Bibliographic searches, a modified Delphi technique, focus groups and interviews with experts on the topic were conducted to identify existing models of agriculture, food, nutrition, health and environmental systems. These models were examined, classified and synthesized into an integrated conceptual model of the food and nutrition system. Few existing models broadly described the system and most focused on one disciplinary perspective or one segment of the system. Four major types of models were identified: food chains, food cycles, food webs and food contexts. The integrated model developed here included three subsystems (producer, consumer, nutrition) and nine stages (production, processing, distribution, acquisition, preparation, consumption, digestion, transport, metabolism). The integrated model considers the processes and transformations that occur within the system and relationships between the system and other systems in the biophysical and social environments. The integrated conceptual model of the food and nutrition system presents food and nutrition activities as part of a larger context and identifies linkages among the many disciplines that deal with the food and nutrition system.

Possible lessons from the tobacco experience for obesity control

Although obesity is increasing to epidemic proportions in many developed countries, some of these same countries are reporting substantial reductions in tobacco use. Unlike tobacco, food and physical activity are essential to life. Yet similar psychological, social, and environmental factors as well as advertising pressures influence the usage patterns of all 3. These similarities suggest that there may be commonalities between factors involved in controlling obesity and tobacco. This review, therefore, seeks to draw lessons from the tobacco experience for the organization of more successful obesity control. Smoking cessation counseling by physicians has been found to be one of the most clinically effective and cost-effective of all disease prevention interventions. When used alone, however, it cannot decrease the cultural acceptability of tobacco and the pressures and cues to smoke. Research and evaluation have shown the key elements of tobacco control to be (1) clinical intervention and management, (2) educational strategies, (3) regulatory efforts, (4) economic approaches, and (5) the combination of all of these into comprehensive programs that address multiple facets of the environment simultaneously. For each element, we present the evidence outlining its importance for tobacco control, discuss its application to date in obesity control, and suggest areas for further research. Viewing all of the elements involved and recognizing their synergistic effects draws researchers and practitioners back from an exclusive concentration on their particular setting to consider how they might seek to influence other settings in which individuals and populations must negotiate desired changes in nutrition and physical activity.

Blood lead concentration and children's anthropometric dimensions in the Third National Health and Nutrition Examination survey (NHANES III), 1988-1994

OBJECTIVE To assess the association between lead exposure and childrens physical growth. DESIGN Cross-sectional analysis of data from the Third National Health and Nutrition Examination Survey, 1988-1994. PARTICIPANTS A total of 4391 non-Hispanic white, non-Hispanic black, and Mexican-American children age 1 to 7 years. MEASUREMENTS AND RESULTS We investigated the association between blood lead concentration and stature, head circumference, weight, and body mass index with multiple regression analysis adjusting for sex, ethnic group, iron status, dietary intake, medical history, sociodemographic factors, and household characteristics. Blood lead concentration was significantly negatively associated with stature and head circumference. Regression models predicted reductions of 1. 57 cm in stature and 0.52 cm in head circumference for each 0.48 micromol/L (10 micrograms/dL) increase in blood lead concentration. We did not find significant associations between blood lead concentration and weight or body mass index. CONCLUSIONS The significant negative associations between blood lead concentration and stature and head circumference among children age 1 through 7 years, similar in magnitude to those reported for the Second National Health and Nutrition Examination Survey, 1976-1980, suggest that although mean blood lead concentrations of children have been declining in the United States for 2 decades, lead exposure may continue to affect the growth of some children.

Sedentary behavior, recreational physical activity, and 7-year weight gain among postmenopausal U.S. women.

Objective: To assess the relationship among recreational physical activity (PA), non‐occupational sedentary behavior, and 7‐year weight gain among postmenopausal U.S. women 40 to 69 years old.