Do adolescent vitamin-mineral supplement users have better nutrient intakes than nonusers? Observations from the CATCH tracking study.

OBJECTIVE: Describe whether users of vitamin-mineral supplements differed from nonusers in micronutrient intakes or in nutrition awareness. DESIGN: Cross-sectional, observational study. SUBJECTS: One thousand five hundred thirty-two students now in grade 8, who participated in the Third Child and Adolescent Trial for Cardiovascular Health tracking study and who also provided a single 24-hour dietary recall. STATISTICAL ANALYSES PERFORMED: Mixed-model analysis of covariance was used to ascertain if supplement users had higher vitamin and mineral intakes from food sources, and to examine if supplement users had better nutrition awareness than nonusers. RESULTS: The 24-hour recall showed that 17.6% of the students reported using vitamin-mineral supplements. Users reported a mean of 1.4 supplements, of which 47% were multivitamin or multimineral preparations, 37% were single nutrients, and 16% were combinations. White persons and residents of Minnesota and California were more likely to be supplement users. Users had higher micronutrient intakes from food sources for 16 of the 20 nutrients studied after adjusting for gender, race/ethnicity, site, treatment condition, and within-school variability. Users had higher scores on a health behavior survey for food choice and slightly but not significantly higher nutrition knowledge scores. CONCLUSIONS: Vitamin-mineral supplement use is prevalent among eighth-grade students. Users have higher nutrient intakes from foods, higher total intakes for several micronutrients, higher nutrition awareness, and differ in their demographic characteristics from nonusers.

Reliability and validity of the Child and Adolescent Trial for Cardiovascular Health (CATCH) Food Checklist: a self-report instrument to measure fat and sodium intake by middle school students.

OBJECTIVE: To develop a scoring algorithm and evaluate the reliability and validity of scores from the Child and Adolescent Trial for Cardiovascular Health (CATCH) Food Checklist (CFC) as measures of total fat, saturated fat, and sodium intake in middle school students. DESIGN: Randomized, controlled trial in which participants were assigned to 1 of 3 study protocols that varied the order of CFC and 24-hour dietary recall administration. Criterion outcomes were percent energy from total fat, percent energy from saturated fat, and sodium intake in milligrams. SUBJECTS/SETTING: A multiethnic sample (33% ethnic and racial minorities) of 365 seventh-grade students from 8 schools in 4 states. STATISTICAL ANALYSES: Multivariable regression models were used to calibrate the effects of individual food checklist items; bootstrap estimates were used for cross-validation; and kappa statistics, Pearson correlations, t tests, and effect sizes were employed to assess reliability and validity. RESULTS: The median same-day test-retest reliability kappa for the 40 individual CFC food items was 0.85. With respect to item validity, the median kappa statistic comparing student choices to those identified by staff dietitians was 0.54. Test-retest reliability coefficients ranged from 0.84 to 0.89 for CFC total nutrient scores. Correlations between CFC scores and 24-hour recall values were 0.36 for total fat, 0.36 for saturated fat, and 0.34 for sodium; CFC scores were consistent with hypothesized gender differences in nutrient intake. APPLICATIONS/CONCLUSIONS: The CFC is a reliable and valid tool for measuring fat, saturated fat, and sodium intake in middle school students. Its brevity and ease of administration make the CFC a cost-effective way to measure middle school students' previous day's intake of selected nutrients in school surveys and intervention studies.

Changes and tracking of physical activity across seven years in Mexican-American and European-American mothers.

Longitudinal changes in physical activity among 129 Mexican-American (mean age 30.8; SD = 5.6) and 97 European-American (mean age 31.2; SD = 5.4) women were studied. Two physical activity recall interviews were administered at baseline and 7 years later. At baseline, European-American women reported more vigorous leisure activity (p < .005) than Mexican-Americans, and Mexican-Americans reported more moderate work activity (p < .02) than European-Americans. Virtually all components of physical activity increased significantly over the 7 years. Pearson tracking correlations for total energy expenditure were about r = 0.30. The finding that both groups increased physical activity overtime was unexpected and was unrelated to a reduction in the number of preschool children in the homes over time.

Fat and sugar levels are high in snacks purchased from student stores in middle schools.

OBJECTIVE: Children consume about one third of their daily energy at school, mostly from cafeteria food and bag lunches. Students also shop at student-run stores that generate revenue for extracurricular activities; yet the nutritional value of snacks sold at student stores has not been documented to our knowledge. DESIGN: Cross-sectional study of foods sold at student stores in middle schools. SUBJECTS/SETTING: Twenty-four San Diego County (Calif) public middle schools, grades 6 through 8 (age 11 to 13), from 9 school districts. The schools represent a diversity of ethnic groups and socioeconomic levels. STATISTICAL ANALYSES PERFORMED: Descriptive statistics, Pearson product moment correlations, analysis of variance. RESULTS: Snacks averaged 8.7 g fat and 23.0 g sugar. Overall, 88.5% of store inventory was high in fat and/or high in sugar. Sugar candy accounted for one third of store sales. Chocolate candy was highest in fat content: 15.7 g. Fourteen of the 24 schools had stores that sold food and were run by student organizations. Stores were open daily for about 90 minutes; half sold food during lunch. CONCLUSIONS: Adolescents need opportunities to supplement main meals; however, student stores in middle schools sell primarily high-fat, high-sugar snacks. Key intervention possibilities include limiting sales of chocolate candy and substituting low-fat varieties of cakes, cookies, chips, and crackers. Competition with cafeterias for sales at lunchtime should be addressed.

Correlations among physical activity and eating behaviors in 4- to 7-year-old Anglo- and Mexican-American children.

Physical activity and dietary behaviors are often correlated in adults and adolescents. This association was examined in 351 Anglo- and Mexican-American children between the ages of 4 and 7 years. Behaviors were assessed by structured observations and interviews at home and school. Observed physical activity was significantly correlated with energy intake (r = .43), but was unrelated to the percentage of calories from total fat or saturated fat. Thus, interventions with young children to improve dietary behavior or physical activity should not be expected to automatically lead to changes in the other.

Determinants of dietary intake in a sample of white and Mexican-American children.

OBJECTIVE: To assess the influence of several potential psychosocial determinants on children's eating behavior. PARTICIPANTS: Three hundred fifty-one Mexican-American and non-Hispanic white children (mean age = 4.4 years old at baseline) participated in the San Diego Study of Children's Activity and Nutrition for up to 2.5 years. METHODS: Child's eating behavior was described by 3 dependent variables: total energy, percentage energy from fat, and sodium intake per 1,000 kcal. Dietary information was collected 4 days a year using a 24-hour food intake record, which was a combination of direct observation and interviews with food preparers. The 35 predictor variables from child, parental, demographic, and environmental domains were collected by behavioral observation, interviewer-administered questionnaires, and physical measurements. STATISTICAL ANALYSES: Bivariate and regression analyses via mixed linear models were performed. RESULTS: Variables from the children's domain (such as skinfold thickness and weight) had the strongest associations with energy intake; parental variables (such as fat avoidance behavior and prompts to increase children's food intake) were associated with child's percentage energy from fat and sodium intake. In regression analyses, parsimonious subsets of variables accounted for 46% of variance in energy intake (3 variables), 40% of the variance in percentage of energy from fat (4 variables), and 44% of variance in sodium intake per 1,000 kcal energy (1 variable) in between-subject variance components. CONCLUSIONS: Fat and sodium intake of children may be improved by improving parents' nutrition habits and by having parents encourage children to eat a healthful diet. Few modifiable correlates of children's energy intake were identified.

Physical activity levels and prompts in young children at recess: a two-year study of a bi-ethnic sample.

We investigated physical activity and encouragement for activity in a bi-ethnic cohort during recess. Activity and associated interactions of 287 children were recorded at preschool and again 2.2 years later. Children expended nearly twice as much energy at preschool recess than at elementary recess. Activity levels declined as recess time elapsed. At preschool, European-American children engaged in more moderate to vigorous activity than Mexican-Americans. As participants moved to elementary school, teachers' prompts to be active decreased and prompts from peers increased. Boys and girls received similar amounts of activity prompts at preschool, but prompts to boys increased over time. The findings suggest that school environments could be altered to promote healthful physical activity among young children.

Improving school breakfasts: effects of the CATCH Eat Smart Program on the nutrient content of school breakfasts.

BACKGROUND: This paper describes the impact of the Eat Smart School Nutrition Program, the food service component of the Child and Adolescent Trial for Cardiovascular Health (CATCH), on the percentage of calories from total fat and saturated fat and the sodium content of school breakfasts. METHODS: Fifty-nine of the 96 CATCH schools offered breakfast. We collected 5 consecutive days of school breakfast menu, recipe, and vendor product information at three periods to assess the nutrient content of the school menus as offered. RESULTS: At baseline (Fall 1991), intervention school breakfasts provided 28% of calories from total fat and control schools 30%. Decreases occurred over time in both groups, but no significant differences were attributable to the intervention (adjusted mean difference = -0.4; P = 0.77). Saturated fat exceeded the Eat Smart goal at baseline in all schools and by follow-up (Spring 1994), the reduction in mean percentage of calories from saturated fat was greater in intervention than in control schools (adjusted mean difference = -1.6%; P = 0.052). Sodium goals were not achieved. Mean calorie levels were maintained at or above Eat Smart goals throughout the study in both groups. Differences over time in other dietary variables (percentage of calories from protein and carbohydrate and mean levels of protein, carbohydrate, calcium, iron, vitamin A value, vitamin C, total sugars, and dietary fiber) were not statistically significant between groups. No significant reductions in student participation in the School Breakfast Program (SBP) occurred. CONCLUSIONS: The Eat Smart food service intervention improved school breakfast composition, but not significantly more so than in control schools. Fat and saturated fat in school breakfasts were lowered while maintaining calories, other essential nutrient levels, and student participation in the SBP. Secular trends and also the possibility that control schools were affected by the Eat Smart intervention may account for these findings.

Impact of fat reduction on micronutrient density of children's diets: the CATCH Study.

BACKGROUND: The purpose of this study was to examine the impact of fat reduction on vitamin and mineral density in the diets of groups of children who participated in the CATCH school-based intervention study for 2 1/2 years. METHODS: Twenty-four-hour dietary recalls were collected on 1,182 children residing in four states and with diverse ethnic backgrounds, at baseline when they were in third grade and again at follow-up when they were in fifth grade. RESULTS: With a 2.4% reduction in total fat intake from baseline levels in the intervention group, mean changes in vitamin and mineral intakes per 1,000 kcal of this group were small yet significant compared with the control group. As mean fat intake decreased, the nutrient density of most vitamins and minerals increased; the sole exceptions were vitamin E and sodium. Mean intake of all vitamins and minerals studied exceeded 2/3 of the RDA at both baseline and follow- up for both the intervention and the control groups. No significant differences were noted between treatment groups for the percentages of children meeting 2/3 or more of the RDA at both baseline and follow-up periods. CONCLUSIONS: CATCH was successful in maintaining mean vitamin and mineral intakes of intervention group children when total dietary fat was reduced.

Changes in nutrient intakes of elementary school children following a school-based intervention: results from the CATCH Study.

BACKGROUND: Twenty-four-hour recalls were used to assess the change in nutrient intake among elementary-age school children exposed to the Child and Adolescent Trial for Cardiovascular Health (CATCH). The purpose of this paper is to compare changes in nutrient intakes between treatment groups, sexes, ethnic groups, and the four CATCH sites. METHODS: Twenty-four-hour recalls were administered to a subsample of the CATCH cohort at baseline in third grade and following the intervention in fifth grade (n = 1,182). Changes in nutrient levels for total energy, dietary cholesterol, and dietary fiber and changes in the proportion of energy from fat, protein, carbohydrate, and fatty acids were studied looking at differences by treatment group, sex, ethnicity, and site. Mixed-model analysis of variance was used to examine the change in nutrient intake, defined as intake at follow-up minus intake at baseline. RESULTS: Students in the intervention schools showed statistically significant differences in the changes in total energy and proportion of energy from total fat, saturated fat, protein, and monounsaturated fat compared with students in the control group. Students in the intervention group decreased their total fat intake from 32.7% of energy to 30.3% of energy and saturated fat from 12.8% of energy to 11.4% of energy. There were no significant differences in intervention effects by ethnic group, sex, or site. Differences in nutrient change between the school-only and the school-plus-family intervention groups were nonsignificant. CONCLUSION: The results show that a school-based intervention can positively influence children's intakes of total fat and saturated fat, suggesting that population-based approaches for reducing cardiovascular risk factors in children are feasible and effective. The results are also important in showing that the intervention was effective in Caucasian, African-American, and Hispanic students, in boys and girls, and across four regions of the United States.

Changes in the nutrient content of school lunches: results from the CATCH Eat Smart Food service Intervention.

BACKGROUND: The Child and Adolescent Trial for Cardiovascular Health (CATCH) tested the effectiveness of a multilevel intervention aimed at promoting a healthful school environment and positive eating and physical activity behaviors in children. The CATCH Eat Smart Program targeted the school food service staff and aimed to lower the total fat, saturated fat, and sodium content of school meals. METHODS: The Eat Smart intervention was conducted in 56 intervention schools over a 2(1/2)-year period.+Five consecutive days of school menu, recipe, and vendor product information were collected from intervention and control schools at three intervals, Fall 1991, Spring 1993, and Spring 1994, to assess the nutrient content of school menus as offered. RESULTS: There was a significantly greater mean reduction in the percentage of calories from total fat (adjusted mean difference -4.1%; P < 0.0001) and saturated fat (adjusted mean difference -1.3%; P = 0.003) in intervention compared with control schools from baseline to follow-up. Although the sodium content of school lunches increased in both conditions, the mean increase was significantly lower in intervention schools (adjusted mean difference -89 mg; P = 0.034). There were no statistically significant differences for total amounts of cholesterol, carbohydrate, protein, dietary fiber, total sugars, calcium, iron, vitamin A value, and vitamin C. Average total calories decreased significantly; however, the mean total calories (683 kcal) for intervention schools remained above one-third of the Recommended Dietary Allowances for this age group. CONCLUSIONS: The CATCH Eat Smart intervention successfully lowered the total fat and saturated fat content of school lunches as offered, while maintaining recommended amounts of calories and essential nutrients.

Marginal vitamin and mineral intakes of young adults: the Bogalusa Heart Study.

PURPOSE: To determine reported vitamin and mineral intakes, vitamin supplement use, and food consumption patterns of young adults. METHODS: Twenty-four-hour dietary recalls were collected from 1988-1991 on a cross-sectional sample of 504 young adults in Bogalusa, Louisiana, between the ages of 19 and 28 years (58% female; 70% white). Reported vitamin and mineral intake data were analyzed for race and gender differences. Descriptive and inferential statistics were calculated where appropriate. Food sources of selected vitamins and minerals were also examined. RESULTS: Reported intakes of vitamins A, B6, E, D, and C, folacin, magnesium, iron, zinc, and calcium were most likely to be inadequate compared with the Recommended dietary Allowances (RDA); with more females than males reported nutrient intakes less than two thirds of the RDA. Approximately 10% of the population reported taking a vitamin/mineral supplement over the 24-h survey period. Food source data indicated that breads and grains, milk, vegetables and soups, fruits, and beef were the primary contributors of the selected vitamins and minerals. CONCLUSIONS: Public health organizations and dietitians need to educate young adults on practical strategies for making wise food choices rich in nutrient content relative to energy value to ensure intakes that approach the RDAs.

Vitamin and mineral intakes of Anglo-American and Mexican-American preschoolers.

OBJECTIVE: To assess vitamin and mineral intakes of Anglo-American and Mexican-American preschoolers. DESIGN: By use of interview and observation methods, acquire food intake data, calculate total nutrient intake, and compare selected nutrients to the Recommended Dietary Allowances (RDAs) for ethnic and gender groups. SUBJECTS: Low- to middle-income parents and their preschool children (N = 351) recruited from preschools in San Diego, Calif, consented to participate in the Study of Children's Activity and Nutrition conducted by researchers at the University of California, San Diego. MAIN OUTCOME MEASURES: Data regarding 15 nutrients were summarized based on the average of two food intake records for each preschooler. STATISTICAL ANALYSES PERFORMED: Means and standard deviations were used to describe micronutrient intakes for ethnic and gender groups; analyses of variance and t tests were performed to determine ethnic and gender differences. RESULTS: Boys and Anglo-Americans had higher total nutrient intakes than girls and Mexican-Americans, respectively. Mexican-Americans had higher nutrient intakes per energy intake, which indicates a micronutrient-dense diet. When each nutrient was considered by the two thirds of the RDA criterion (66% of the RDA means adequate intake), the nutrients most likely to be inadequate were iron, zinc, vitamin D, vitamin C, and niacin. Mexican-American girls had significantly lower calcium intakes than the other gender and ethnic groups. APPLICATION: Parents and day care providers must ensure that preschoolers, especially girls and Mexican-Americans, eat nutrient-rich foods in adequate quantities that will achieve the recommended intakes.

CATCH: food service program process evaluation in a multicenter trial.

Process evaluation is an essential element of a multicenter trial in order to explain study outcomes and monitor intervention progress. This paper presents the process evaluation model for the Eat Smart School Nutrition Program, the food service intervention component of the Child and Adolescent Trial for Cardiovascular Health (CATCH), and describes the process evaluation strategies developed to assess this program. The paper details (1) measures of program implementation including training, support visits, and program promotion, (2) food service staff characteristics, and (3) measures of mediating variables including secular trends and school meal participation.

Validation of 24-hour recalls assisted by food records in third-grade children. The CATCH Collaborative Group.

OBJECTIVE: The objective of the study was to validate the use of 24-hour recalls assisted by food records as a dietary assessment tool for use with third-grade children. DESIGN: Trained staff observed children during mealtime at school, and parents observed and recorded what children ate in their presence. The following day children participated in a 24-hour recall interview. Children's ability to recall what they consumed during a 24-hour period was compared with observational data collected during the same period. SETTING: All data were collected in elementary school settings at four sites involved in the Child and Adolescent Trial for Cardiovascular Health. SUBJECTS: The sample of 49 children was self-selected, based on parents' willingness to observe and record their child's food intake. MAIN OUTCOME MEASURES: Recalled and observed data for energy and nutrient levels were compared using mean energy and nutrient analysis and quartile classification. In addition, recalled and observed foods were compared by meal type and estimation of portion size. STATISTICAL ANALYSIS PERFORMED: Paired t tests, Pearson and Spearman correlations, and classification analysis were used to compare recalled and observed data. RESULTS: Comparison of observed and recalled food intakes showed no significant differences in percentage of energy from total fat, saturated fat, monounsaturated fat, and polyunsaturated fat or in the amount of sodium consumed, although there were differences in energy intakes. Spearman rank order correlations between recalled and observed nutrients ranged from .45 to .79. A 77.9% agreement was found across all meals in the food items children recalled having consumed compared with those adults actually observed them consuming. CONCLUSIONS: We conclude that the 24-hour recall assisted by food records is a valid method for assessing the dietary intake of children as young as 8 years old for the purpose of group comparison.

Infant-feeding practices and adiposity in 4-y-old Anglo- and Mexican-Americans.

A longer duration of breast-feeding and later introduction to solids may protect against excessive adiposity in infancy. This study investigated infant feeding practices and their relationship to two measures of adiposity--body mass index (BMI) and sum of skinfold thicknesses (SUMSF)--in 331 4-y-old Anglo- (43%) and Mexican-American (57%) children. No associations were detected between any of the infant feeding variables of duration of breast-feeding and introduction to solids and formula and measures of the child's adiposity. Mother's physical measures of BMI and SUMSF explained the largest portion of variance for both measures of childhood adiposity, BMI (9.5%), and SUMSF (8.3%). Genetic and environmental factors other than infant feeding practices appear to have a greater influence on a 4-y-olds' adiposity.

Effect of nitrous oxide on the concentrations of opioid peptides, substance P, and LHRH in the brain and beta-endorphin in the pituitary.

Many studies have indicated that nitrous oxide (N2O) exposure results in specific effects on the reproductive system, some of which are antigonadotropic. The neurochemical events regulating the pituitary-gonadal axis are probably influenced by N2O, but precise documentation is lacking. The effects of exposure to 30% N2O in air on the brain tissue concentrations of luteinizing hormone releasing hormone (LHRH), substance P (SP), met-enkephalin, and beta-endorphin and on beta-endorphin concentrations of the pituitary gland are described in this study. Female rats were exposed to either N2O or air for 8 hr a day over one estrous cycle, and the brain and pituitary tissues were collected and processed. Neuropeptide concentrations were measured by specific radioimmunoassays. Exposure to N2O resulted in significant elevation of LHRH in the preoptic area, with a concomitant decrease in SP. The SP concentration of the medial basal hypothalamus was significantly elevated in N2O-exposed animals. Exposure to N2O resulted in significant increases in met-enkephalin in the brainstem area and beta-endorphin in the pituitary. These results suggest that exposure to N2O alters the interactive neural system activity regulating gonadotropin secretion from the pituitary. The significance of increased met-enkephalin in the brainstem of N2O-exposed animals is not known.