2008年 11月 01日
Weight Gain in Older Adolescent Females: The Internet, Sleep, Coffee, and Alcohol
The Journal of Pediatrics Volume 153, Issue 5, November 2008, Pages 635-639.e1
To examine whether excessive recreational Internet time, insufficient sleep, regular coffee consumption, or alcoholic beverages promote weight gain.
A longitudinal cohort of >5000 girls (Growing Up Today Study), from all over the United States and aged 14 to 21 years, returned surveys in 2001 reporting typical past-year recreational Internet time, sleep, coffee (with caffeine), and alcohol consumption. We estimated correlations among these 4 exposures. Each girl also reported her height and weight in 2000 and again in 2001. Multivariate models investigated associations between 1-year change in body mass index and same-year exposures, adjusted for adolescent growth/development, activity, and inactivity.
The exposures were highly (P < .0001) correlated with each other, except for coffee with Internet time (P > .50). More Internet time, more alcohol, and less sleep were all associated (P < .05) with same-year increases in body mass index. Females, aged 18+ years, who slept ≤5 hours/night (P < .01) or who consumed alcohol 2+servings/week (P < .07) gained more body mass index from 2000 to 2001. For females in weight-promoting categories of all exposures, this translates to nearly 4 extra pounds gained over 1 year. We found no evidence that drinking coffee promotes weight gain.
Older girls may benefit from replacing recreational Internet time with sleep and by avoiding alcohol.
Abbreviations: BMI, Body mass index; NHSII, Nurses' Health Study II
Effects of Average Childhood Dairy Intake on Adolescent Bone Health
The Journal of Pediatrics Volume 153, Issue 5, November 2008, Pages 667-673
To evaluate the effects of usual childhood dairy intake on adolescent bone health.
Dietary data collected in the Framingham Children's Study over 12 years were used to evaluate usual dairy consumption and adolescent bone health. Each child's average Food Pyramid servings were estimated from yearly sets of 3-day diet records. Bone mineral content (BMC) and area (BA) for total body and 6 regions (arms, legs, trunk, ribs, pelvis, and spine) at ages 15 to 17 years were the primary outcomes. Analysis of covariance was used to adjust for potential confounding by sex and physical activity, as well as age, height, body mass index and percent body fat at the time of the bone scan.
Consuming ≥ 2 servings/day of dairy (versus less) was associated with significantly higher mean BMC and BA. Higher intakes of meats/other proteins (≥ 4 servings per/day) were also associated with higher mean BMC and BA values. Children with higher intakes of both dairy and meats/other proteins had the highest adjusted BMC (3090.1 g), and children consuming less of each had the lowest BMC (2740.2 g).
These prospective data provide evidence for a beneficial effect of childhood dairy consumption on adolescent bone health.
Abbreviations: BA, Bone area; BMC, Bone mineral content; BMD, Bone mineral density; BMI, Body mass index; DXA, Dual energy X-ray absorptiometry; FCS, Framingham Children's Study; USDA, United States Department of Agriculture