Correlates of persistent thinness in black and white young women

OBJECTIVE: To examine health and psychosocial correlates of persistent thinness in black and white young adult women. RESEARCH METHODS AND PROCEDURES: 1,830 females (n = 988 black, n = 842 white) who participated in the National Heart, Lung, and Blood Institute Growth and Health Study were asked to indicate their current body size from a series of nine pictograms (1, emaciated to 9, obese). Persistent thinness was defined as having at least seven non-missing measurement points between ages 9 to 18 with a body size rating of <4 at all points. Generalized linear models were used to examine whether persistently thin women differed from comparison women on cardiovascular disease risk factors measured at age 18.5 and psychosocial variables measured at age 21.5. Prospective associations between psychological measures in childhood and persistent thinness through the course of adolescence were also examined. RESULTS: In the sample, 145 women (7.9%) met criteria for persistent thinness and 1,685 women (92.1%) were classified as not persistently thin. Persistently thin women had a later age of menarche, fewer weight concerns, and healthier eating attitudes, were less likely to have had a child, came from higher socioeconomic backgrounds, and had significantly lower blood pressure and higher high-density lipoprotein-cholesterol than comparison women. Differences were not found on measures of depression or health services use. Girls with higher self-esteem in childhood were more likely to remain persistently thin throughout adolescence. DISCUSSION: Persistently thin women seem to be healthier on several indicators relative to comparison women, and race did not moderate these differences.     

Anthropometric measurements of white and black southern adolescent girls

Anthropometric measurements of 691 white and 550 black 12-, 14-, and 16-year-old girls from three income groups, residing in the southern United States, were evaluated, Heights, weights, mid-upper arm circumferences, and arm muscle areas of 14-year-old girls were significantly higher than those of 12-year-old girls and significantly lower than those of girls 16 years of age; triceps skinfolds, arm fat areas, and body mass indexes of 12-year-olds were significantly lower than those of older subjects. Blacks had significantly higher weights, body mass indexes, and arm muscle areas than whites. Black 12-year-old girls were significantly taller than white 12-year-old girls but significantly shorter than older girls of either race; white 16-year-old girls were significantly taller than blacks of that age. Body mass indexes of black 12-year-olds and white 14-year-olds were significantly higher than those of white 12-year-olds, and significantly lower than those of black 14- and 16-year-olds. Medium-income blacks and whites of all income levels had lower (usually significantly) weights, body mass indexes, mid-upper arm circumferences, arm muscle areas, and arm fat areas than low- and high-income blacks did. Anthropometric values of white, but not of black, girls were generally similar to those reported in surveys of primarily white girls.     

Energy expenditure in preadolescent African American and white boys and girls: the Baton Rouge Children's Study

BACKGROUND: Low energy expenditure has been identified as a potential risk factor for body fat gain. OBJECTIVE: The objective was to determine the relations between race, sex, body fat, and energy expenditure. DESIGN: As part of the Baton Rouge Children's Study, energy expenditure was examined in 131 preadolescent African American and white girls and boys, further stratified as obese or lean. Total daily energy expenditure (TDEE) was measured by the doubly labeled water method. Resting metabolic rate (RMR) and the thermic effect of food were measured by indirect calorimetry. Fat-free mass and fat mass were measured by dual-energy X-ray absorptiometry. To account for differences in body size, energy expenditure variables were adjusted with the use of fat-free mass or fat-free mass and fat mass as covariates. RESULTS: The African American children had lower TDEE and RMR than did the white children. A lower level of energy expended in physical activity by the African American girls and a lower RMR in the African American boys accounted for the racial differences in TDEE. The white boys had a higher RMR than did the white girls. The girls had a lower TDEE and expended less energy in activity than did the boys. Energy expended in activity was lower in the obese children. CONCLUSIONS: The African American children expended less energy than did the white children. The obese children spent less time engaged in activity or engaged in lower-intensity activity. Obese children may maintain their obese state by spending less time in physical activity, but they do not have a reduced RMR or thermic effect of food.     

Discrepancies among predictors of desirable weight for black and white obese adolescent girls.

Desirable weights were determined for 26 black and white, postmenarchal girls (11 to 15 years old) with juvenile-onset obesity. Each subject was measured for height, weight, triceps and subscapular fatfolds, and body density by underwater weighing (UWW). Body mass indexes and desirable weights were determined by UWW, from the US National Health Examination Survey (NHES) data, and from the Slaughter fatfold equation to estimate body fat. Desirable weights obtained from NHES growth charts were consistently lower than those obtained from UWW, especially for blacks (P less than .01). Findings from both the Slaughter fatfold equation and percent body fat from UWW indicated that growth charts provide lower-than-appropriate weight goals for both black and white obese girls. Results of our study suggest that health professionals should consider a measurement of body composition or at least increase desirable weights by 10% to 30% when setting weight recommendations from weight-for-height charts for obese adolescent girls.     

Differences in physical activity between black and white girls living in rural and urban areas

This study examined the relationship of race and rural/urban setting to physical, behavioral, psychosocial, and environmental factors associated with physical activity. Subjects included 1,668 eighth-grade girls from 31 middle schools: 933 from urban settings, and 735 from rural settings. Forty-six percent of urban girls and 59% of rural girls were Black. One-way and two-way ANOVAs with school as a covariate were used to analyze the data. Results indicated that most differences were associated with race rather than setting. Black girls were less active than White girls, reporting significantly fewer 30-minute blocks of both vigorous and moderate-to-vigorous physical activity. Black girls also spent more time watching television, and had higher BMIs and greater prevalence of overweight than White girls. However, enjoyment of physical education and family involvement in physical activity were greater among Black girls than White girls. Rural White girls and urban Black girls had more favorable attitudes toward physical activity. Access to sports equipment, perceived safety of neighborhood, and physical activity self-efficacy were higher in White girls than Black girls.     

Self-esteem and adiposity in black and white girls: The NHLBI growth and health study

PURPOSE: Obesity is assumed to have a negative impact on self-esteem because of the associated social stigmatization in Western society. Studies of the psychological effect of obesity in children are inconclusive and limited, particularly pertaining to minority populations. Most studies have assessed global rather than domain-specific measures of self-esteem and hence, may have lacked specificity to detect impairment of certain aspects of self-esteem most closely associated with obesity. The purpose of this study is to examine the effect of adiposity and other environmental factors on measures of perceived competence and self-adequacy in 2205 black and white girls aged 9–10 years.

METHODS: Domain-specific measures of self-esteem were studied by race and degree of adiposity, using Harter's “Self-Perception Profile for Children”. Three Harter scales deemed more relevant to obesity (social acceptance (SA), physical appearance (PA), and global self-worth (GSW)) were selected for univariate and multivariate linear regression models to examine relationships between self-esteem level and adiposity (measured by the sum of triceps, subscapular, and suprailiac skinfolds (SSF)), race, pubertal maturation, and parental education. The relationship between adiposity and Harter scores was further examined with LOESS curves and also by comparing the mean scores of each quintile of SSF by race, as well as inter-quintile differences within race.

RESULTS: Adiposity in general impacted negatively on the scores of all three selected Harter scales. There was also racial variation in the relationship between the scores and adiposity, with the magnitude of the effect somewhat less in black girls. White girls exhibited a significant inverse relationship between SSF and SA scores while, in striking contrast, there was no variation in scores in black girls across all ranges of adiposity. Although there was a significant inverse relationship between adiposity and PA and GSW in both groups, the slope was steeper in white girls, particularly at higher ranges of SSF. Non-linearity in the relationship between SSF and the scores was seen in SA and PA scales.

CONCLUSIONS: The present study demonstrated a significant negative association between adiposity and the level of self-esteem in girls as young as 9 to 10 years. There were also intriguing racial differences in the selected domains of esteem. These results may help better understand cultural differences regarding the psychological impact of obesity and could be used to formulate appropriate strategies for public health policy.     

Zinc retention and losses of zinc in sweat by preadolescent girls.

Preadolescent girls, ages 7 to 9 years, were fed levels of zinc ranging from 5.61 to 14.61 mg/day during an 18-day metabolic study. All other nutrients were provided at or above Recommended Dietary Allowance levels. The sweat loss of zinc was measured using an arm-bag method and whole body zinc loss was calculated from whole body nitrogen and arm loss of nitrogen and zinc. Fecal zinc reflected dietary zinc, but urinary zinc remained relatively stable. The mean daily loss of zinc through sweat was calculated to be 1.43 mg. Zinc retentions were not significantly different (P greater than 0.05) though the retention increased generally with intake of zinc. A comparison of these data with previously reported studies indicated that the absorption of zinc was usually in the range of 20 to 30%. Based on sweat losses reported by others and found in this study and on usual absorption of zinc, it appears that diets should provide a minimum of 7 mg of zinc daily for growing children.     

Income and racial patterns of dietary vitamin C intake among black and white girls.

The authors examined the influence of income and race on mean dietary vitamin C intake and the risk of dietary vitamin C intake at levels below the recommended dietary allowance (RDA). They performed a cross-sectional analysis of 2,032 black and white 9- and 10-year-old females, from a wide range of income groups, who participated in the National Heart, Lung, and Blood Institute Growth and Health Study. Mean intake of vitamin C, exclusive of vitamin supplements and determined by 3-day diet records, exceeded the RDA of 45 milligrams per day for that age group in all racial and income categories. The investigators found that annual household income was directly associated with mean dietary vitamin C intake (P < 0.0001) and that blacks had higher mean dietary vitamin C intakes than whites (P < 0.01). Among both blacks and whites, household income and risk of below-RDA vitamin C intake were inversely correlated, but this trend was statistically significant for blacks only (P < 0.05). Except for the lowest level income group (less than $10,000 per year), black girls from households with incomes less than $30,000 per year were at increased risk for below-RDA vitamin C intake (relative risk = 1.93 in the $10,000-$19,999 per year group and 1.63 in the $20,000-29,999 per year group, P < 0.05), compared with black girls in the highest income category. One-quarter of white girls overall and more than 30 percent of white girls in the lowest two income groups had below-RDA vitamin C intakes.(ABSTRACT TRUNCATED AT 250 WORDS)     

Racial differences in accuracy of self-assessment of sexual maturation among young black and white girls.

PURPOSE: To examine the validity of maturation self-assessments and to investigate the association between race and validity of self-assessments among young black and white girls. METHODS: Self-assessments and examiner-assessments of areolar and pubic hair development using line drawings were compared at three visits among a cohort of 11- to 14-year-old girls enrolled in the National Heart, Lung, and Blood Institute's Growth and Health Study. Accuracy rates and kappa coefficients were calculated to measure the agreement between girls and examiners. Logistic regression models were used to assess the racial differences in the accuracy of self-assessments while adjusting for possible confounders. RESULTS: Fair to moderate agreement was found between self- and examiner-assessments (areolar self-assessments: adjusted accuracy rates: 60.7-69.9%, kappa: 0.32-0.51; pubic hair self-assessments: adjusted accuracy rates: 57.9-70.7%, kappa: 0.36-0.55). While there were indications of racial differences in the ability to perform self-assessment with black girls tending to self-assess less accurately, most of the differences disappeared after adjusting for nurse-assessed stage. CONCLUSIONS: These findings suggest that self-assessment can substitute for examiner evaluations only when crude estimates of maturation are needed. However, when accurate maturation stage data are required, examiner-assessments are necessary. Because black girls are usually more pubertally advanced and tend to underestimate their development, the value of self-assessment is questionable for assessing populations with young black and white girls. Use of self-assessment might present biased estimates of maturation and confound research findings.     

Drive for thinness score is a proxy indicator of energy deficiency in exercising women

The purpose of this study was to determine the association between drive for thinness (DT) and adaptations to energy deficiency in exercising women. This observational study evaluated psychometric and metabolic factors in sedentary (n=9, 27.9+/-2.0 yr) and exercising women (n=43, 24.0+/-1.1 yr). Volunteers were retrospectively grouped according to exercise status (sedentary or exercising) and a DT score of normal (sedentary or exercising) or high (exercising only). Resting energy expenditure (REE) and metabolic hormones (triiodothyronine, (TT3), ghrelin, leptin, insulin) were measured repeatedly over a 2-3 month period. The DT subscale successfully discriminated the groups based on energy status. Although the groups did not differ in body weight, the high DT group exhibited adaptations to chronic energy deficiency, including a REE below 90% of their predicted REE (86+/-3.0%), significantly lower TT3 levels and significantly higher ghrelin levels than the normal DT groups. Since energy deficiency plays a causal role in the Female Athlete Triad, DT may serve as a proxy indicator of underlying energy deficiency and may be useful for identifying individuals at risk for Triad disorders prior to the development of serious clinical sequelae.     

Assessing the introduction of universal human papillomavirus vaccination for preadolescent girls in The Netherlands

A persistent infection with human papillomavirus (HPV) is a prerequisite for the development of cervical cancer. Clinical trials with HPV-vaccines have been very successful in preventing persistent HPV16/18 infections, the two most oncogenic HPV-genotypes. We assessed the introduction of universal HPV-vaccination for preadolescent girls in the Dutch National Immunization Programme. Long-term vaccine efficacy, the need and extent of a catch-up programme for young women, and the impact of vaccination on the cervical cancer screening programme are major unresolved issues. Preliminary conservative estimates (80% vaccine efficacy and no effects on the screening programme, transmission rate, non-cervical cancer incidence, and cross protection) predict an acceptable cost-effectiveness ratio for universal vaccination of preadolescent girls.     

Weight status and psychosocial factors predict the emergence of dieting in preadolescent girls

OBJECTIVE: The current study tested a longitudinal model predicting the emergence of dieting in girls (n = 183) at age 9 years using data from the same girls measured at ages 5 and 7. METHOD: Variables related to the girls' weight status, psychological health, body satisfaction, maternal child feeding practices, and family environment are included in a hierarchical regression model predicting the emergence of dieting in girls. Interactions of girls' weight status with other variables in the model are also included in the last step. RESULTS: Results indicate that the model accounts for 45% of the variance in the outcome scores and that variables across constructs have significant contributions to the model. Results also show that girls' weight status, both independently and as an interaction term, accounts for a large proportion of variance in this model. CONCLUSION: Weight status at age 5 years is a critical factor related to the emergence of dieting in young girls.     

Research in black and white

The authors consider the methodological, interpretative, and practical issues that arise when there is a difference in ethnicity between researcher and informant in qualitative research by drawing on the academic literature and their fieldwork experiences as White researchers undertaking studies with individuals of African/Caribbean and South Asian descent. Some contemporary issues raised by "researching the other" in the context of pragmatic health services research are highlighted, including access to same-ethnicity researchers, the involvement of interpreters, and the potential for ethnocentric interpretation. The authors believe that qualitative research should be judged by the plausibility of the findings and by a critical evaluation of the way in which the research was conducted and the reflexivity of the researcher.