Prediction and Cross-validation of an Energy Expenditure Equation in Walking or Running in Asian Adults.

The prevalence of obesity is increasing across the world. Knowledge of the actual energy expenditure (EE) of walking and running can lead to a more precise exercise prescription which may contribute to obesity reduction or avoidance. Limited research has focused on EE prediction during walking or running in Asian adults. So, the aims of this study included developing an EE prediction equation and cross-validating the equation for Asian adults. METHODS: A total of 85 Asians participated to test EE through indirect calorimetry. Linear regression analysis was employed for EE prediction, and a dependent t-test and Chow statistical test were used to cross-validate the equation. RESULTS: Predicting EE during walking or running, corrected for one mile, yielded the following equation: EE = 0.933 * (Body Weight) - 4.127 * Gender (M = 1, F = 2) + 44.256 (standard error of estimate, SEE = 12.1 kcal·mile-1). A dependent t-test revealed no significant difference between measured EE (101.4 ± 4.3 kcal) and predicted EE (100.0 ± 2.8 kcal) (p = 0.546). Also, the coefficients for body weight and gender between the development prediction equation and the predicted equation in the cross-validation group were not significantly different (p = 0.365). CONCLUSION: The cross-validation results supported the validity of our predicted equation in Asians. In a practical field setting, exercise professionals could apply this equation for assessing EE during walking or running, corrected for one mile, in normal weight (body fat percentage ≤ 22 for males, ≤ 35 for females) and overweight (body fat percentage > 22 for males, > 35 for females) Asian adults.

Comparison and predicted equation of energy expenditure during walking or running among Caucasians, African Americans and Asians.

Knowledge of measured energy expenditure (EE) during walking and running is important for exercise prescription. Further, research on the EE comparison and EE predicted equation during walking or running among different ethnicities is limited. The purpose of the current study was to compare EE to walk or run 1 mile in Caucasian, African American and Asian adults and to develop a regression equation to predict EE to walk or run 1 mile. Two hundred and twenty-four participants were included (71 Caucasians, 68 African Americans and 85 Asians) with 3 groups (normal weight walking, overweight walking and running). EE was measured via indirect calorimetry. Analysis of variance was used to compare EE across groups. Multiple regression analysis was employed for EE prediction, and the prediction equation was cross-validated. A significant EE difference was found between walking and running among three ethnicities. The prediction equation was: EE â€‹= â€‹0.978 Body Weight - 4.571 Gender (male=1; female=2) â€‹+ â€‹3.524 Ethnicities (Caucasians=1, African Americans=2, Asians=3) â€‹+ â€‹32.447 (standard error of estimate=12.5 â€‹kcal·mile-1). The equation was valid through cross-validation, so it is recommended to apply for calculating EE during walking or running 1 mile among Caucasians, African Americans and Asians.

Geographic Disparity in Funding for School Nutrition Environments: Evidence from Mississippi Schools.

BACKGROUND: Despite the federal initiatives on equitable provision of school nutrition programs, geographic disparity in childhood obesity persists. It may be partly because built-in school nutrition environments rely on each school's efficient use of existing operational funds or its ability to obtain expanded financial support. This study explores how funding acquisition by schools is determined by local community characteristics and how it relates to healthy school meal offerings. METHODS: Information about food preparation technology and funding in 811 schools in Mississippi was obtained by in-depth phone interviews of district child nutrition directors and school foodservice managers, which was matched to socioeconomic indicators of schools and communities. Probit models were estimated. RESULTS: About 56% of schools in the sample received some funds toward combination oven/steamers in the last few years. Small schools, schools in non-metro counties, and those in low-income minority areas were significantly less likely to be funded. Obtainment of funds was associated with a 45 percentage-point reduction in the probability of serving fried foods. CONCLUSIONS: Funds obtained by schools for advanced food preparation technology contributes to creation of healthier nutrition environments for children. However, fund availability is associated with community characteristics, possibly contributing to geographic disparity of child health.

Pedometer determined physical activity tracks in African American adults: the Jackson Heart Study.

BACKGROUND: This study investigated the number of pedometer assessment occasions required to establish habitual physical activity in African American adults. METHODS: African American adults (mean age 59.9 ± 0.60 years; 59 % female) enrolled in the Diet and Physical Activity Substudy of the Jackson Heart Study wore Yamax pedometers during 3-day monitoring periods, assessed on two to three distinct occasions, each separated by approximately one month. The stability of pedometer measured PA was described as differences in mean steps/day across time, as intraclass correlation coefficients (ICC) by sex, age, and body mass index (BMI) category, and as percent of participants changing steps/day quartiles across time. RESULTS: Valid data were obtained for 270 participants on either two or three different assessment occasions. Mean steps/day were not significantly different across assessment occasions (p values > 0.456). The overall ICCs for steps/day assessed on either two or three occasions were 0.57 and 0.76, respectively. In addition, 85 % (two assessment occasions) and 76 % (three assessment occasions) of all participants remained in the same steps/day quartile or changed one quartile over time. CONCLUSION: The current study shows that an overall mean steps/day estimate based on a 3-day monitoring period did not differ significantly over 4 - 6 months. The findings were robust to differences in sex, age, and BMI categories. A single 3-day monitoring period is sufficient to capture habitual physical activity in African American adults.

Physical activity and obesity in African Americans: the Jackson Heart Study.

OBJECTIVES: To better understand how obesity and low levels of physical activity (PA) contribute to racial health disparities, we examined the association of PA domains (work, home life, and leisure) with indicators of socioeconomic status and markers of obesity in African Americans. METHODS: These cross sectional analyses of interview and clinical measures from the baseline visit of the Jackson Heart Study of cardiovascular disease (CVD) in African Americans of the Jackson, Mississippi metropolitan statistical area included 3,174 women and 1,830 men aged 21-95 years. The main measures were active living, sport, work, home life, and total PA scores; participation in regular moderate or vigorous intensity leisure physical activity (MVLPA); demographics, body mass index (BMI), waist circumference (WC) and CVD risk factors. RESULTS: The sample was 63% female, 81% high school or college graduates, with 51% aged 45-64 years, and mostly overweight (32%) or obese (53%). Women were less active than men in all domains except home life. Total PA was inversely associated with WC in women and men. The overweight (BMI 25-29.9) group was most active in all domains except work; active living and sport PA and prevalence of MVLPA then declined in a dose response association with increasing BMI. Work PA was associated with the lowest BMI but otherwise with indicators of less favorable socioeconomic status and health. CONCLUSIONS: Observed differences in PA in African Americans by domain and association with obesity biomarkers suggest areas for future study and intervention to reduce health disparities.

Serum carotenoid and tocopherol concentrations vary by dietary pattern among African Americans.

BACKGROUND: Intakes and biochemical concentrations of carotenoids and tocopherols have been associated with chronic diseases. OBJECTIVE: To describe dietary patterns in Jackson Heart Study participants and to determine if biochemical measurements of antioxidants differ across these. DESIGN: Cross-sectional analysis of data for 373 African-American men and women (age 35 to 80 years), participating in the Diet and Physical Activity Substudy of the Jackson Heart Study. METHODS: Dietary intake was assessed with a region specific food frequency questionnaire. Patterns were defined by cluster analysis of food groups, as percent of energy intake. RESULTS: Four dietary patterns were identified: fast food, Southern, prudent, and juice. Individuals in the fast-food pattern (n=153) had significantly lower serum concentrations of lutein plus zeaxanthin and beta-cryptoxanthin; those in the Southern cluster (n=99) had significantly lower serum alpha-carotene; and those in the prudent (n=63) and juice (n=58) clusters had significantly higher serum alpha-carotene and beta-cryptoxanthin (P<0.05) relative to those in at least one other cluster (all P<0.05). The juice cluster also had higher serum alpha-tocopherol concentrations relative to the fast-food cluster. CONCLUSIONS: Diets high in fast foods, snacks, soft drinks, and meat were associated with relatively low concentrations of carotenoids and alpha-tocopherol. This pattern contained the largest number of participants, and could contribute to the extensive health disparities seen in this region.

Dietary assessment in African Americans: methods used in the Jackson Heart Study.

OBJECTIVES: The dietary assessment methods used in the Jackson Heart Study (JHS) with the entire cohort and a subset of the cohort who participated in a diet and physical activity substudy (DPASS) are reported. These methods were employed to validate culturally explicit data collection instruments developed by Delta Nutrition Intervention Research Initiative (NIRI) for assessing dietary intake in an all African-American cohort. DESIGN: A validation/calibration design was employed. A short food frequency questionnaire (FFQ) was used with all JHS participants (N=5302). A long FFQ and four 24-hour diet recalls were used for the subset of DPASS participants (n=449). OUTCOME MEASURES: Completion rates and preliminary macronutrient intakes are reported for the cohort and DPASS methods. RESULTS: Participants (5302) in the JHS full cohort completed the short FFQ. Of these, 572 were enrolled in the DPASS. A total of 506 participants completed four 24-hour dietary recalls, and 499 completed all six measures, including the long FFQ. Validation of dietary instruments in African Americans will help assure that valid conclusions can be drawn regarding the effects of diet on cardiovascular disease in this population.

Physical activity assessment methods in the Jackson Heart Study.

OBJECTIVES: Physical activity measures used in exam 1 of the Jackson Heart Study (JHS), including the diet and physical activity substudy (DPASS), are described. DESIGN: The JHS physical activity (PAC) survey instrument was administered by interview. Accelerometer data, pedometer step counts, and additional questionnaire data were collected from volunteer subsamples of the cohort, including the DPASS. OUTCOME MEASURES: The PAC assessed four different domains of physical activity (active living, work, home and garden, and sport and exercise indexes). The 24-hour accelerometer and pedometer monitoring provided objective measures for validation of cohort survey responses. The DPASS past week activity (PWA) questionnaire assessed time spent in moderate and vigorous activity during the previous seven days. Pedometer step counts for three days before three DPASS visits provided additional data for the DPASS. RESULTS: 5296 respondents completed the PAC, 423 completed 24-hour accelerometer monitoring, and 499 completed the DPASS measures; 85 completed both 24-hour monitoring and DPASS measures. Initial analyses of leisure and sports activity items showed similar distributions for men and women and for the cohort and DPASS participants, in a bimodal distribution, with similar proportions reporting infrequent and frequent activity. The physical activity measures from the JHS can provide unique information about the association between physical activity, other risk factors, and cardiovascular disease in African Americans.