Racial and Ethnic Differences in Longitudinal Patterns of Family Mealtimes: Link to Adolescent Fruit and Vegetable Consumption.

OBJECTIVE: To examine the longitudinal patterns of family mealtimes across racial/ethnic groups and to investigate whether the associations between longitudinal patterns of family mealtimes, baseline family and demographic characteristics, and healthy food consumption in adolescence differ by race/ethnicity. METHODS: Data from the Early Childhood Longitudinal Study spanning from kindergarten to eighth grade were used for this study. Longitudinal patterns of family mealtimes and their link to baseline characteristics and healthy food consumption in adolescence, as defined by fruit and vegetable intakes, were determined using latent growth curves. RESULTS: From childhood to adolescence, family mealtimes were stable among Asian families. Although Hispanic families displayed a downward pattern, mealtimes declined more steeply in non-Hispanic white and black families. The links among family mealtimes, baseline characteristics, and healthy food consumption were not observed equally across racial/ethnic groups. CONCLUSIONS AND IMPLICATIONS: Differences in longitudinal patterns of family mealtimes and in the association between family mealtimes and adolescent healthy food consumption across racial/ethnic groups call for targeted intervention in this nutritionally vulnerable period.

Risk Assessment of Arsenic in Rice Cereal and Other Dietary Sources for Infants and Toddlers in the U.S.

Currently, there are no set standards or quantitative guidelines available in the U.S. for arsenic levels in rice cereal, one of the most common first solid foods for infants. The objective of this study was to evaluate whether the detected levels of inorganic arsenic (As(i)) in rice cereal in the U.S. market are safe for consumption by infants and toddlers. A risk assessment was conducted based on literature reviews of the reported As(i) in rice cereal from the U.S. Food and Drug Administration's (FDA) survey and the recommended daily intake of rice cereal by body weight, for infants and toddlers between four and 24 months old. As a part of risk management, a maximum contaminant level (MCL) for Asi in rice cereal was computed considering overall exposure sources including drinking water, infant formula, and other infant solid foods. Hazard quotients (HQs) for acute and chronic exposures were calculated based on the U.S. Agency for Toxic Substances and Disease Registry's (ATSDR) Minimal Risk Level (MRL)(acute) (5.0 × 10(-3) mg/kg/day) and MRL(chronic) (3.0 × 10(-4) mg/kg/day). A cancer slope or potency factor of 1.5 mg/kg/day was used to predict an incremental lifetime cancer risk (ILCR). Exposure assessment showed that the largest source of As(i) for infants and toddlers between four and 24 months old was rice cereal (55%), followed by other infant solid food (19%), and drinking water (18%). Infant formula was the smallest source of As(i) for babies (9%) at the 50th percentile based on Monte Carlo simulations. While HQ(acute) were consistently below 1.0, HQ(chronic) at the 50 and 75th percentiles exceeded 1.0 for both rice cereal and total sources. ILCR ranged from 10(-6) (50th) to 10(-5) (75th percentile). MCLs for As(i) in rice cereal ranged from 0.0 (chronic) to 0.4 mg/kg (acute exposures).

Effect of beta-alanine supplementation on the onset of blood lactate accumulation (OBLA) during treadmill running: Pre/post 2 treatment experimental design.

BACKGROUND: beta-Alanine (betaA) has been shown to improve performance during cycling. This study was the first to examine the effects of betaA supplementation on the onset of blood lactate accumulation (OBLA) during incremental treadmill running. METHODS: Seventeen recreationally-active men (mean +/- SE 24.9 +/- 4.7 yrs, 180.6 +/- 8.9 cm, 79.25 +/- 9.0 kg) participated in this randomized, double-blind, placebo-controlled pre/post test 2-treatment experimental design. Subjects participated in two incremental treadmill tests before and after 28 days of supplementation with either betaA (6.0 g.d-1)(betaA, n = 8) or an equivalent dose of Maltodextrin as the Placebo (PL, n = 9). Heart rate, percent heart rate maximum (%HRmax), %VO2max@OBLA (4.0 mmol.L-1 blood lactate concentration) and VO2max (L.min-1) were determined for each treadmill test. Friedman test was used to determine within group differences; and Mann-Whitney was used to determine between group differences for pre and post values (p < 0.05). RESULTS: The betaA group experienced a significant rightward shift in HR@OBLA beats.min-1 (p < 0.01) pre/post (161.6 +/- 19.2 to 173.6 +/- 9.9) but remained unchanged in the PL group (166.8 +/- 15.8 to 169.6 +/- 16.1). The %HRmax@OBLA increased (p < 0.05) pre/post in the betaA group (83.0% +/- 9.7 to 88.6% +/- 3.7) versus no change in the PL group (86.3 +/- % 4.8 to 87.9% +/- 7.2). The %VO2max@OBLA increased (p < 0.05) in the betaA group pre/post (69.1 +/- 11.0 to 75.6 +/- 10.7) but remained unchanged in the PL group (73.3 +/- 7.3 to 74.3 +/- 7.3). VO2max (L.min-1) decreased (p < 0.01) in the betaA group pre/post (4.57 +/- 0.8 to 4.31 +/- 0.8) versus no change in the PL group (4.04 +/- 0.7 to 4.18 +/- 0.8). Body mass kg increased (p < 0.05) in the betaA group pre/post (77.9 +/- 9.0 to 78.3 +/- 9.3) while the PL group was unchanged (80.6 +/- 9.1 to 80.4 +/- 9.0). CONCLUSIONS: betaA supplementation for 28 days enhanced sub-maximal endurance performance by delaying OBLA. However, betaA supplemented individuals had a reduced aerobic capacity as evidenced by the decrease in VO2max values post supplementation.