Otten Jennifer J, Jones Katherine E, Littenberg Benjamin, Harvey-Berino Jean
Department of Nutrition, University of Vermont, Burlington, USA.
Arch Intern Med. 2009 Dec 14;169(22):2109-15. doi: 10.1001/archinternmed.2009.430.
The average adult watches almost 5 hours of television (TV) per day, an amount associated with increased risks for obesity. This trial examines the effects of TV reduction on energy intake (EI), energy expenditure (EE), energy balance, body mass index (BMI), (calculated as weight in kilograms divided by height in meters squared), and sleep in overweight and obese adults.
Randomized controlled trial of 36 adults with a BMI of 25 to 50 who self-reported a minimum of 3 h/d of TV viewing. Participants were enrolled in home-based protocols from January through July 2008. After a 3-week observation phase, participants were stratified by BMI and randomized to an observation-only control group (n = 16) or an intervention group (n = 20) for 3 additional weeks. The intervention consisted of reducing TV viewing by 50% of each participant's objectively measured baseline enforced by an electronic lock-out system.
Although not statistically significant, both groups reduced their EI (-125 kcal/d [95% CI, -303 to 52] vs -38 [95% CI, -265 to 190]) (P = .52) for intervention and control group participants, respectively, where CI indicates confidence interval. The intervention group significantly increased EE (119 kcal/d [95% CI, 23 to 215]) compared with controls (-95 kcal/d [95% CI, -254 to 65]) (P = .02). Energy balance was negative in the intervention group between phases (-244 kcal/d [95% CI, -459 to -30]) but positive in controls (57 kcal/d [95% CI, -216 to 330]) (P = .07). The intervention group showed a greater reduction in BMI (-0.25 [95% CI, -0.45 to -0.05] vs -0.06 [95% CI, -0.43 to 0.31] in controls) (P = .33). There was no change in sleep.
Reducing TV viewing in our sample produced a statistically significant increase in EE but no apparent change in EI after 3 weeks of intervention. Trial Registration clinicaltrials.gov Identifier: NCT00622050.
普通成年人每天看电视的时间接近5小时，这一时长与肥胖风险增加有关。本试验旨在研究减少看电视时间对超重和肥胖成年人的能量摄入（EI）、能量消耗（EE）、能量平衡、体重指数（BMI，计算方法为体重（千克）除以身高（米）的平方）以及睡眠的影响。
对36名BMI在25至50之间且自我报告每天看电视至少3小时的成年人进行随机对照试验。参与者于2008年1月至7月纳入家庭干预方案。经过3周的观察期后，参与者按BMI分层，随机分为仅观察对照组（n = 16）或干预组（n = 20），再进行3周试验。干预措施包括通过电子锁定系统将每位参与者经客观测量的基线看电视时间减少50%。
尽管差异无统计学意义，但干预组和对照组参与者的EI均有所降低（干预组为-125千卡/天[95%CI，-303至52]，对照组为-38千卡/天[95%CI，-265至190]）（P = 0.52），其中CI表示置信区间。与对照组（-95千卡/天[95%CI，-254至65]）相比，干预组的EE显著增加（119千卡/天[95%CI，23至215]）（P = 0.02）。干预组在两个阶段之间的能量平衡为负（-244千卡/天[95%CI，-459至-30]），而对照组为正（57千卡/天[95%CI，-216至330]）（P = 0.07）。干预组的BMI降幅更大（-0.25[95%CI，-0.45至-0.05]，对照组为-0.06[95%CI，-0.43至0.31]）（P = 0.33）。睡眠情况无变化。
在我们的样本中，减少看电视时间在干预3周后使EE有统计学意义的增加，但EI无明显变化。试验注册 clinicaltrials.gov标识符：NCT00622050。
