Association between television in bedroom and adiposity throughout adolescence.

OBJECTIVE: The objective was to determine if having a television (TV) in the bedroom is associated with physical activity (PA), TV/video viewing, and adiposity throughout adolescence. RESEARCH METHODS AND PROCEDURES: Longitudinal data (September 2002 through June 2005) were analyzed of 379 initially 12-year-old French adolescents participating as controls in the Intervention Centered on Adolescents' Physical activity and Sedentary behavior (ICAPS). Presence of a TV set in the bedroom (TV(bedroom)) and leisure activities were obtained by questionnaire. There was annual assessment of BMI, waist circumference, and body fat by bioimpedance. RESULTS: In boys but not girls, baseline TV(bedroom) was associated with higher TV/video viewing over time [odds ratio (OR) of high TV/video = 1.87; 95% confidence interval, 1.2 to 2.8] and less no-sport club participation (OR = 0.59; 95% confidence interval, 0.35 to 1.0). Both boys and girls with baseline TV(bedroom) had lower reading time (p < 0.0001 in boys; p = 0.04 in girls), while PA did not differ according to TV(bedroom) for boys or for girls. For boys only, baseline TV(bedroom) was associated with higher BMI (mean BMI over time 20.5 +/- 0.5 vs. 19.0 +/- 0.5 kg/m(2); p = 0.001), waist circumference (70.9 +/- 0.9 vs. 67.2 +/- 0.8 cm; p < 0.001), and body fat (15.9 +/- 0.9% vs. 13.5 +/- 0.9%; p < 0.001), without interaction with time. These relationships remained significant after adjustment for socioeconomic status. TV/video viewing explained 26%, 42%, and 36% of the relationships of TV(bedroom) with BMI, waist circumference, and body fat, respectively, while addition of other leisure activities in the models only marginally reduced the effects. DISCUSSION: These results suggest the importance of keeping TV out of an adolescent's bedroom from an obesity prevention perspective but show gender differences.

Diet and physical activity profiles in French preadolescents.

Dietary patterns have been identified in adults, but less is known about children and adolescents. For the first time, we have investigated lifestyle patterns combining diet and physical activity in 12-year-old French preadolescents and examined their association with sociodemographic factors. Physical activity, sedentary activities and dietary habits were assessed by questionnaires given to 2724 students in 2001. Family income tax and parents' educational level, as indicators of socio-economic status, and the size of the residence commune were obtained from parents. After adjusting for socio-economic status, physical activity was positively associated with a consumption of fruit/vegetables/fruit juice on more than four occasions in the previous 24 h (P<0.001). Sedentary activities were positively associated with the consumption of French fries or potato chips (P<0.001), with sweetened drink as the most usual drink (P<0.001) and with nibbling while watching television (P<0.001), and inversely associated with a high consumption of fruit/vegetables/fruit juice (P=0.04). Multiple correspondence analysis identified two independent axes and specific combinations of behaviour: one axis characterised by sedentary activity, sweetened drink as the most usual drink, the consumption of French fries or potato chips and nibbling while watching television; a second one associating physical activity and the consumption of fruit/vegetables/fruit juice. Both socio-economic proxies were associated with the former axis (P<0.001). The size of the residence commune was associated with the latter (P<0.1). Combinations of diet and physical activity habits were identified in adolescents, indicating that prevention programmes targeting both behaviours may have an enhanced outcome.

Plasma fatty acid composition is associated with the metabolic syndrome and low-grade inflammation in overweight adolescents.

BACKGROUND: Together with adiposity, plasma fatty acid (FA) composition can modulate the development of the metabolic syndrome (MS). OBJECTIVE: Our aim was to investigate the relations of FA composition in plasma phospholipids and cholesterol esters (CEs) with weight status, MS, and inflammation in adolescents. DESIGN: Plasma FA composition was measured by gas-liquid chromatography in 120 (60 normal-weight and 60 overweight) 12-y-old adolescents. We also measured the presence of MS, insulin resistance with the homeostasis model assessment, and interleukin 6 and C-reactive protein concentrations in the adolescents. RESULTS: MS was present in 25% of the overweight adolescents but in none of the normal-weight adolescents. Compared with overweight adolescents, normal-weight adolescents had lower saturated FAs (SFAs) in both phospholipids (P < 0.001) and CEs (P < 0.01) and higher docosahexaenoic acid in phospholipids (P < 0.001). In overweight subjects, FA composition was associated with MS features independent of body fat. The odds ratios of MS for a 0.1 increase in the ratio of polyunsaturated FAs (PUFA) to SFAs (PUFA:SFA) were 0.91 in phospholipids (P = 0.03) and 0.90 in CEs (P = 0.06). In phospholipids, PUFA:SFA and linoleic acid were associated positively with HDL cholesterol (P < 0.01 for both). PUFA:SFA in phospholipids and CEs were associated inversely with interleukin 6 (P < 0.05 for both). Eicosapentaenoic acid in phospholipids (P = 0.06) and CEs (P < 0.05) and linolenic acid in CEs (P < 0.05) were inversely related to C-reactive protein. These relations remained significant after adjustment for the waist-to-hip ratio. No significant relation between FA composition and the homeostasis model assessment was observed. CONCLUSIONS: Plasma FA composition is associated with weight status in healthy adolescents. High intake of long-chain PUFAs, especially n-3 PUFAs, may protect obese subjects against MS and low-grade inflammation as early as adolescence.