Sex and race/ethnicity specific reference predictive equations for abdominal adiposity indices using anthropometry in US adults.

BACKGROUND AND AIMS: Abdominal adiposity indices have stronger associations with cardiometabolic risk factors compared to anthropometric measures but are rarely used in large scale studies due to the cost and efficiency. The aim of this study is to establish sex and race/ethnicity specific reference equations using anthropometric measures. METHODS AND RESULTS: A secondary data analysis (n = 6589) of healthy adults was conducted using data from National Health and Nutrition Examination Survey 2011-2018. Variables included in the analyses were anthropometric measures (height; weight; waist circumference, WC) and abdominal adiposity indices (android percent fat; android to gynoid ratio, A/G ratio; visceral adipose tissue area, VATA; visceral to subcutaneous adipose area ratio, VSR). Multivariable prediction models were developed using quantile regression. Bland-Altman was used for external validation of prediction models. Reference equations to estimate android percent fat, A/G ratio, VATA and VSR from anthropometric measurements were developed using a randomly selected subsample of 4613. These reference equations for four abdominal adiposity indices were then cross-validated in the remaining subsample of 1976. The measured and predicted android percent fat, A/G ratio, VATA and VSR were not statistically different (p > 0.05) except for the A/G ratio in Asian males and VSR in White females. The results of Bland-Altman further revealed that ≥93% of predicted abdominal adiposity indices fell within the limits of agreement (±1.96 standard deviation). CONCLUSION: The sex and race/ethnicity specific reference equations for abdominal adiposity indices established using anthropometrics in the present study have strong predictive ability in US healthy adults.

The Sex and Race/Ethnicity-Specific Relationships of Abdominal Fat Distribution and Anthropometric Indices in US Adults.

The purpose of this study was to examine demographic-specific relationships between direct abdominal fat measures and anthropometric indices. A cross-sectional study was conducted utilizing abdominal fat measures (visceral fat area, VFA; visceral to subcutaneous adipose area ratio, VSR) and anthropometrics (body mass index, BMI; waist circumference, WC) data from the 2011-2018 National Health and Nutrition Examination Survey. Linear or polynomial linear regression models were used to examine the relationships of abdominal fat measures to anthropometrics with adjustment for demographics. The results revealed that while VFA was linearly related to BMI and WC across all demographics (p < 0.001), the relationships between VSR and both BMI and WC were concave in men and convex in women. The relationships between VFA, VSR, and BMI, WC varied by sex and race/ethnicity. In conclusion, increasing BMI and WC were linearly associated with increased VFA, but their relationships with VSR were nonlinear and differed by sex.

The Demographic Specific Abdominal Fat Composition and Distribution Trends in US Adults from 2011 to 2018.

Despite the rising awareness of abdominal adiposity associated health problems and demographic health disparities, research is lacking about abdominal fat trends using a national representative sample of US adults. Our purpose was to examine national demographic specific abdominal fat composition and distribution trends from 2011 to 2018. This trend analysis was using National Health and Nutrition Examination Survey data (n = 13,163). Visceral adipose percent (VAT%), visceral adipose tissue area (VAA) and visceral to subcutaneous adipose area ratio (VSR) were utilized in data analyses. Multiple polynomial linear regression was utilized with adjustment for confounding variables. Our findings revealed that VAT%, VAA and VSR trends were concave among all demographic groups. The VAT%, VAA and/or VSR changes were observed in most demographic groups (p < 0.05) except younger, White and Black respondents. The pattern was consistent with biennial increases up to 2014 or 2016 followed by decreases in 2017-2018. There were demographic disparities, with middle-aged respondents and Hispanics having the most evident VAT%, VSR and/or VAA changes biennially when compared to their counterparts (p < 0.05). In conclusion, abdominal fat composition and distribution increased before 2014 or 2016 but decreased afterwards with variations by age and/or race/ethnicity. Further research is needed to explore the possible causes of abdominal fat changes overtime.

The Association between US Adolescents' Weight Status, Weight Perception, Weight Satisfaction, and Their Physical Activity and Dietary Behaviors.

Background: It remain unclear that the association between weight status, weight perception, weight satisfaction and the clustering of physical activity (PA) and dietary behaviors in adolescents. Method: A cross-sectional analysis of National Health and Nutrition Examination Survey and the US Department of Agriculture's Food Patterns Equivalents 2007⁻2014 data from adolescents aged 12⁻17 years (n = 2965) was conducted. Multivariable logistic regression models adjusted for demographic characteristics examined the association between weight status, weight perception, weight satisfaction, and the four created lifestyle groups (healthier behaviors, healthier diet only, physically active only, unhealthier behaviors). Results: Males with obesity were more likely to be in the healthier diet only group than males with a normal weight (OR = 1.90, 95% CI: 1.02, 3.52). Similar patterns were found in males who perceived themselves as being overweight or having obesity (OR = 2.09, 95% CI: 1.09, 3.99) and males with obesity who perceived their weight status accurately (OR = 2.33, 95% CI: 1.12, 4.88). Female respondents who were satisfied with their weight were 59% less likely to be in the healthier diet only group than healthier behaviors group compared with females who were weight dissatisfied (OR = 0.41, 95% CI: 0.23, 0.75). This pattern was not observed in males. Conclusions: Clustering PA and dietary behaviors were associated with weight status and weight perception for males but not females. Weight satisfaction was associated with clustered PA and dietary behaviors for females. These findings are important for obesity prevention policies and programs to better address adolescents' obesity and reduce health disparities in this population.

Survey Development to Assess College Students' Perceptions of the Campus Environment.

OBJECTIVE: We developed and tested a College Environmental Perceptions Survey (CEPS) to assess college students' perceptions of the healthfulness of their campus. METHODS: CEPS was developed in 3 stages: questionnaire development, validity testing, and reliability testing. Questionnaire development was based on an extensive literature review and input from an expert panel to establish content validity. Face validity was established with the target population using cognitive interviews with 100 college students. Concurrent-criterion validity was established with in-depth interviews (N = 30) of college students compared to surveys completed by the same 30 students. Surveys completed by college students from 8 universities (N = 1147) were used to test internal structure (factor analysis) and internal consistency (Cronbach's alpha). RESULTS: After development and testing, 15 items remained from the original 48 items. A 5-factor solution emerged: physical activity (4 items, α = .635), water (3 items, α = .773), vending (2 items, α = .680), healthy food (2 items, α = .631), and policy (2 items, α = .573). The mean total score for all universities was 62.71 (±11.16) on a 100-point scale. CONCLUSION: CEPS appears to be a valid and reliable tool for assessing college students' perceptions of their health-related campus environment.

The Green Eating Project: web-based intervention to promote environmentally conscious eating behaviours in US university students.

OBJECTIVE: To investigate the effectiveness of an online, interactive intervention, referred to as the Green Eating (GE) Project, to motivate university students to adopt GE behaviours. DESIGN: The study was quasi-experimental and integrated into courses for credit/extra credit. Courses were randomly stratified into experimental or non-treatment control. The 5-week intervention consisted of four modules based on different GE topics. Participants completed the GE survey at baseline (experimental, n 241; control, n 367) and post (experimental, n 187; control, n 304). The GE survey has been previously validated and consists of Transtheoretical Model constructs including stage of change (SOC), decisional balance (DB: Pros and Cons) and self-efficacy (SE: School and Home) as well as behaviours for GE. Modules contained basic information regarding each topic and knowledge items to assess content learning. SETTING: The GE Project took place at a public university in the north-eastern USA. SUBJECTS: Participants were full-time students between the ages of 18 and 24 years. RESULTS: The GE Project was effective in significantly increasing GE behaviours, DB Pros, SE School and knowledge in experimental compared with control, but did not reduce DB Cons or increase SE Home. Experimental participants were also more likely to be in later SOC for GE at post testing. CONCLUSIONS: The GE Project was effective in increasing GE behaviours in university students. Motivating consumers towards adopting GE could assist in potentially mitigating negative consequences of the food system on the environment. Future research could tailor the intervention to participant SOC to further increase the effects or design the modules for other participants.

Increasing breastfeeding in WIC participants: cost of formula as a motivator.

OBJECTIVE: To assess the cost of infant formula, explore mothers' perceptions of formula cost, and assess whether cost influences the decision to breastfeed. METHODS: A mixed-methodological descriptive study with survey (phase 1) and interviews (phase 2) was completed in Rhode Island Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) offices. Thirty non-breastfeeding mothers participated in phase 1 and 14 pregnant women participated in phase 2. Means and frequencies were calculated for phase 1. For phase 2, data were organized into matrices and thematic analysis identified key themes. RESULTS: Non-breastfeeding mothers were spending an extra $46 a month on average in their child's fourth month on formula beyond the formula supplied by WIC. This was perceived as high, but formula cost did not influence their decision to breastfeed. For mothers intending to breastfeed, cost information was perceived as an additional motivation. CONCLUSIONS AND IMPLICATIONS: Information on supplemental formula cost could be provided as a motivator for women intending to breastfeed. Future research should investigate how cost information could be used to support breastfeeding initiation and duration among WIC mothers.

Assessment of the dining environment on and near the campuses of fifteen post-secondary institutions.

OBJECTIVE: The present study evaluated the restaurant and dining venues on and near post-secondary campuses varying in institution size. DESIGN: The Nutrition Environment Measures Survey for Restaurants (NEMS-R) was modified to evaluate restaurants as fast food, sit down and fast casual; and campus dining venues as dining halls, student unions and snack bar/cafe´s. ANOVA with post hoc Tukey's B and T tests were used to distinguish differences between dining venues and associated institutions by size. SETTING: The study was conducted at fifteen US post-secondary institutions, 2009­2011. SUBJECTS: Data presented are from a sample of 175 restaurants and sixty-eight on-campus dining venues. RESULTS: There were minimal differences in dining halls by institution size, although medium-sized institutions as compared with small-sized institutions offered significantly more healthful side dish/salad bar items. Dining halls scored significantly higher than student unions or snack bar/cafe´s on healthful entre´es, side dish/salad bar and beverages offerings, but they also had the most barriers to healthful dietary habits (i.e. all-you-can-eat). No differences were found by restaurant type for NEMS-R scores for total restaurant dining environment or healthful entre´es and barriers. Snack bars had more healthful side dishes (P50?002) and fast-food restaurants had the highest level of facilitators (i.e. nutrition information; P50?002). CONCLUSIONS: Based on this evaluation in fifteen institutions, the full campus dining environment provides limited support for healthy eating and obesity prevention. The quality of campus dining environments can be improved via healthful offerings, providing nutrition information and other supports to facilitate healthy eating and prevent unwanted weight gain.

Impact of an online healthful eating and physical activity program for college students.

PURPOSE: To identify impact of an online nutrition and physical activity program for college students. DESIGN: Randomized, controlled trial using online questionnaires and on-site physical and fitness assessments with measurement intervals of 0 (baseline), 3 (postintervention), and 15 months (follow-up). SETTING: Online intervention delivered to college students; a centralized Web site was used for recruitment, data collection, data management, and intervention delivery. SUBJECTS: College students (18-24 years old, n = 1689), from eight universities (Michigan State University, South Dakota State University, Syracuse University, The Pennsylvania State University, Tuskegee University, University of Rhode Island, University of Maine, and University of Wisconsin). INTERVENTION: A 10-lesson curriculum focusing on healthful eating and physical activity, stressing nondieting principles such as size acceptance and eating competence (software developer: Rainstorm, Inc, Orono, Maine). MEASURES: Measurements included anthropometrics, cardiorespiratory fitness, fruit/vegetable (FV) intake, eating competence, physical activity, and psychosocial stress. ANALYSIS: Repeated measures analysis of variance for outcome variables. RESULTS: Most subjects were white, undergraduate females (63%), with 25% either overweight or obese. Treatment group completion rate for the curriculum was 84%. Over 15 months, the treatment group had significantly higher FV intake (+.5 cups/d) and physical activity participation (+270 metabolic equivalent minutes per week) than controls. For both groups, anthropometric values and stress increased, and fitness levels decreased. Gender differences were present for most variables. First-year males and females gained more weight than participants in other school years. CONCLUSION: A 10-week online nutrition and physical activity intervention to encourage competence in making healthful food and eating decisions had a positive, lasting effect on FV intake and maintained baseline levels of physical activity in a population that otherwise experiences significant declines in these healthful behaviors.

Sneakers and spokes: an assessment of the walkability and bikeability of U.S. postsecondary institutions.

The purpose of the study described in this article was to assess the walkability and bikeability of 15 U.S. postsecondary education campuses. The Centers for Disease Control and Prevention's evidence-based Healthier Worksite Initiative Walkability Audit was modified to rate campus walking and biking path segments for path safety, quality, and comfort. Universities (n = 13) assessed an average of 44 path segments, which earned a mean score of 72.71 +/- 10.77 SD (possible range 0 to 100). Postsecondary technical schools (n = 2) assessed 20 path segments, which received an average score of 76.56 +/- 13.15. About 70% of path segments received a grade A or B, but almost 1 in 10 received a failing or poor support score for walking and biking. Nearly half or more campus environments scored significantly below an acceptable score on many path safety and quality criteria. Postsecondary education campuses that are supportive of walking and biking offer numerous benefits to the environment and people. Findings from environmental assessments like the data reported here can provide valuable input to campus planners.

Sweet and salty. An assessment of the snacks and beverages sold in vending machines on US post-secondary institution campuses.

This study assessed the nutritional quality of snacks and beverages sold in vending machines. The contents of snack and beverage vending machines in 78 buildings on 11 US post-secondary education campuses were surveyed. Of the 2607 snack machine slots surveyed, the most common snacks vended were salty snacks (e.g., chips, pretzels) and sweets (i.e., candy and candy bars). The 1650 beverage machine slots assessed contained twice as many sugar-sweetened beverages as non-calorie-containing beverages. Only two institutions sold both milk and 100% juice in vending machines. The portion of snacks and beverages sold averaged more than 200 cal. Neither snacks nor beverages were nutrient dense. The majority of snacks were low in fiber and high in calories and fat and almost half were high in sugar. Most beverages were high in calories and sugar. This study's findings suggest that vending machines provide limited healthful choices. Findings from benchmark assessments of components of the food environment, like the vending options reported here, can provide valuable input to campus administrators, health services, food service, and students who want to establish campus policies to promote healthful eating.

Evaluation of a short dietary assessment instrument for percentage energy from fat in an intervention study.

The need for an inexpensive measure of dietary intake in intervention studies led to evaluation of the National Cancer Institute (NCI) Percentage Energy from Fat short instrument (PFat) in a subgroup of the Behavioral Change Consortium (BCC) intervention sites. The PFat's performance was evaluated using multiple nonconsecutive 24-h dietary recalls (24HR) as a reference instrument among participants at baseline in 4 demographically diverse intervention sites of the BCC. Mean estimates of percentage energy from fat for 24HR and PFat were within 2.1 percentage points of each other in all but 2 site/gender comparisons. 24HR and PFat estimates were not significantly different (P < 0.05) among men for 2 of 3 sites, and among women for 2 of 4 sites. Deattenuated Pearson correlation coefficients for the PFat and true intake (as estimated from the 24HR using a measurement error model) were significantly different from 0 (P < 0.05) for men and women in all sites, ranging from 0.52 to 0.77 among men and 0.36 to 0.59 among women. Besides gender and site, no other factors examined (age, education, smoking status, and BMI) consistently moderated validity estimates. If accurate assessment of diet at baseline (and presumably at follow-up) is essential, a more detailed instrument such as multiple 24HR may be warranted. The question of whether the PFat adequately measures change in diet is addressed in another article in this supplement.