Ebbeling Cara B, Sinclair Kelly B, Pereira Mark A, Garcia-Lago Erica, Feldman Henry A, Ludwig David S
Division of Endocrinology, Department of Medicine, Children's Hospital, Boston, Mass 02115, USA.
JAMA. 2004 Jun 16;291(23):2828-33. doi: 10.1001/jama.291.23.2828.
Fast food consumption has increased greatly among children in recent years, in tandem with the obesity epidemic. Fast food tends to promote a positive energy balance and, for this reason, may result in weight gain. However, if fast food and obesity are causally related, the question arises of why some children who frequently eat fast food do not become overweight.
To test the hypothesis that overweight adolescents are more susceptible to the adverse effects of fast food than lean adolescents.
In study 1, we fed participants an "extra large" fast food meal in a naturalistic setting (a food court). The participants were instructed to eat as much or little as desired during this 1-hour meal. In study 2, we assessed energy intake under free-living conditions for 2 days when fast food was consumed and 2 days when it was not consumed. Data were collected in Boston, Mass, between July 2002 and March 2003.
Overweight (n = 26) and lean (n = 28) adolescents aged 13 to 17 years. Overweight was defined as a body mass index exceeding sex- and age-specific 85th percentiles based on the 2000 Centers for Disease Control and Prevention growth charts.
Energy intake determined by direct observation in study 1 and by unannounced 24-hour dietary recalls, administered by telephone, in study 2.
In study 1, mean (SEM) energy intake from the fast food meal among all participants was extremely large (1652 [87] kcal), accounting for 61.6% (2.2%) of estimated daily energy requirements. Overweight participants ate more than lean participants whether energy was expressed in absolute terms (1860 [129] vs 1458 [107] kcal, P =.02) or relative to estimated daily energy requirements (66.5% [3.1%] vs 57.0% [2.9%], P =.03). In study 2, overweight participants consumed significantly more total energy on fast food days than non-fast food days (2703 [226] vs 2295 [162] kcal/d; +409 [142] kcal/d; P =.02), an effect that was not observed among lean participants (2575 [157] vs 2622 [191] kcal/d; -47 [173] kcal/d; P =.76).
In this study, adolescents overconsumed fast food regardless of body weight, although this phenomenon was especially pronounced in overweight participants. Moreover, overweight adolescents were less likely to compensate for the energy in fast food, by adjusting energy intake throughout the day, than their lean counterparts.
近年来，儿童快餐消费大幅增加，与此同时肥胖症也在流行。快餐往往会促进能量正平衡，因此可能导致体重增加。然而，如果快餐与肥胖存在因果关系，那么就会出现一个问题：为什么一些经常吃快餐的孩子没有超重？
检验超重青少年比瘦青少年更容易受到快餐不利影响这一假设。
在研究1中，我们在自然环境（美食广场）中给参与者提供一顿“超大份”快餐。参与者被要求在这1小时的用餐时间内想吃多少就吃多少。在研究2中，我们评估了在自由生活条件下，食用快餐的2天和不食用快餐的2天的能量摄入情况。数据于2002年7月至2003年3月在马萨诸塞州波士顿收集。
13至17岁的超重青少年（n = 26）和瘦青少年（n = 28）。超重的定义是根据2000年疾病控制与预防中心的生长图表，体重指数超过特定性别和年龄的第85百分位数。
在研究1中通过直接观察确定能量摄入，在研究2中通过电话进行的不预先通知的24小时饮食回顾来确定能量摄入。
在研究1中，所有参与者从快餐中摄入的平均（标准误）能量极大（1652 [87]千卡），占估计每日能量需求的61.6%（2.2%）。无论能量是以绝对值表示（1860 [129]千卡对1458 [107]千卡，P =.02）还是相对于估计每日能量需求表示（66.5% [3.1%]对57.0% [2.9%]，P =.03），超重参与者摄入的能量都比瘦参与者多。在研究2中，超重参与者在吃快餐的日子里摄入的总能量显著高于不吃快餐的日子（2703 [226]千卡/天对2295 [162]千卡/天；增加409 [142]千卡/天；P =.02），而在瘦参与者中未观察到这种效应（2575 [157]千卡/天对2622 [191]千卡/天；减少47 [173]千卡/天；P =.76）。
在本研究中，无论体重如何，青少年都会过度食用快餐，尽管这种现象在超重参与者中尤为明显。此外，与瘦青少年相比，超重青少年通过调整全天能量摄入来补偿快餐中能量的可能性较小。
