These data and results published in the literature show that BMI and %fat relationship are not independent of age and gender. These data showed a race effect for women, but not men. The failure to adjust for these sources of bias resulted in substantial differences in the proportion of subjects defined as obese by measured %fat.

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OBJECTIVE:To determine if the relationship between abdominal visceral fat (AVF) and measures of adiposity are different between Black and White subjects and to develop valid field prediction models that accurately identify those individuals with AVF levels associated with high risk for chronic disease. DESIGN: Cross-sectional measurements obtained from 91 Black men, 137 Black women, 227 White men, and 237 White women subjects, ages 17-65 y, who were participants in the HERITAGE Family Study, both at baseline and following 20 weeks of endurance training. MEASURMENTS: AVF, abdominal subcutaneous fat (ASF), abdominal total fat (ATF), and sagittal diameter (SagD) were measured by computed tomography (CT). Body density was determined by hydrostatic weighing and was used to estimate relative body fat. Arm, waist (WC), and hip circumferences and skinfold thickness measures were taken, and BMI was calculated from weight (kg) and height (m 2 ). Since CT abdominal fat variables were skewed, a natural log transformation (Ln) was used to produce a normal distribution. The General Linear Model (GLM) procedure was used to test the relationship between AVF and two different groups of variablesFCT and anthropometric. RESULTS: The AVF of White men and women was significantly higher than that of Black men and women, independent of BMI, WHR, WC, and age, and was greater for men than for women. The CT model showed that the combination of SagD, Ln (ASF), age, and race accounted for 84 and 75% of the variance in AVF in men and women, respectively. The anthropometric model provided two valid generalized field AVF prediction equations. The Field-I equation, which included BMI, WHR, age and race, had an r 2 of 0.78 and 0.73 for men and women, respectively. The Field-II equation, which included BMI (women only), WC, age, and race, had an r 2 of 0.78 and 0.72 for men and women, respectively. The field model equations became less accurate as the estimated AVF increased. CONCLUSIONS: (1) At the same age and level of adiposity, Black men and women have less AVF than White men and women. These differences are greater in men than in women. (2) The field regression equations can be generalized to the diverse group of adults studied, both in an untrained and trained state. However, their accuracy decreases with increasing levels of AVF.

Trends in populations of lesser prairie chickens (Tympanuchus pallidicinctus) in the Texas Panhandle were investigated by censusing drumming grounds annually on two study areas during a 10-year period, 1952-62, for comparison with data from a census of the same areas in 1942. Severe drops in populations came in 1952. The decline was triggered by onset of a major drouth lasting through 1956, but populations did not increase during a series of good rainfall years starting with 1957. Changing land-use practices are responsible for keeping lesser prairie chickens at low population levels in the Texas Panhandle. The more important of these are overgrazing of cattle range, particularly in dry weather, resulting in displacement of the tall grasses; accelerated programs of aerial spraying with herbicides for brush control; and combine harvesting of grain sorghum in place of storage by stacking and shocking in the field.

Obesity is a major health problem in the U.S., especially for Hispanic youth. Because maximal/peak oxygen consumption (V.O (2)peak) is one predictor of future weight gain in children, valid field-based methods for determining V.O (2)peak in Hispanic children are needed. The purpose of this study was to validate a field-based aerobic fitness test, the 20-m shuttle test (20-MST), in Hispanic boys (n = 58) and girls (n = 67), 10 - 12 years old (mean age +/- SD, 10.7 +/- 0.6 y). Measured V.O (2)peak was determined during a maximal, graded treadmill test using the Bruce protocol. The 20-MST was administered per a standard protocol. Maximal speed attained on the 20-MST and age were used to estimate V.O (2)peak. An intraclass coefficient of 0.82 was obtained on 35 students (16 boys; r = 0.85 and 19 girls; r = 0.79) who completed the 20-MST twice, 1-wk apart. Estimated (44.3 ml x kg (-1) x min (-1) ) and measured (45.1 ml x kg (-1) x min (-1)) V.O (2)peak were not significantly different (p = 0.33). The correlation between the two V.O (2)peak parameters was r = 0.62; p < 0.001, the standard error of the estimate (SEE) was 3.91 ml x kg (-1) x min (-1), and 85.5 % of the measured V.O (2)peak values fell within 5.9 ml x kg (-1) x min (-1) of estimated V.O (2)peak. The weight status of the child did not significantly change these results. The 20-MST combined with the Leger et al. equation is a valid method for predicting V.O (2)peak in Hispanic youth. The test can be used to provide valuable information for intervention design and disease prevention.

OBJECTIVE: To describe the problem of obesity in Mexican American children and provide a method for identifying Mexican American children at risk for obesity. DESIGN: Cross-sectional and retrospective cohort study. SUBJECTS: Mexican American children, ages 5 ± 11 (kindergarten (K) ± 5th grade) were studied in cross-sectional (girls 463, boys 448) and retrospective (girls 124, boys 92) samples. MEASUREMENTS: Weights (kg) and heights (cm) were extracted from each child's school medical records. Measurements were made by the school nurses (one nurse per school). Body mass index (BMI [wah 2 ]) was calculated from obtained weights and heights. RESULTS: The prevalence of obesity in the cross-sectional sample was 27.4% for girls and 23.0% for boys. The highest prevalence was noted in 4th grade for both the girls (32.4%) and boys (43.4%). The 5 year incidence rates derived from the retrospective sample were 17.7% for girls and 21.1% for boys. The largest increase in the number of girls becoming obese was observed between K and 1st grade (15.6%). The largest increase for boys was found between the 1st and 2nd grades (13.2%). Logistic regression parameters were calculated to estimate the probability of becoming obese in 5th grade given a child's K BMI. Using the generated equation, BMIs in K equal to 16.5, 20.9, and 23.7 would have a 21.0%, 70.0%, and 91.0% probability of being obese by 5th grade. CONCLUSION: This study provides schools with a simple procedure for identifying Mexican American children at risk for obesity. This procedure may assist in the development and implementation of interventions aimed at averting the onset of obesity in this population.

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