Departments of Nutritional Sciences, The Pennsylvania State University, University Park, PA.
Departments of Food Science, The Pennsylvania State University, University Park, PA.
Am J Clin Nutr. 2019 May 1;109(5):1361-1372. doi: 10.1093/ajcn/nqy383.
Although short-term studies have found that serving larger portions of food increases intake in preschool children, it is unknown whether this portion size effect persists over a longer period or whether energy intake is moderated through self-regulation.
We tested whether the portion size effect is sustained in preschool children across 5 consecutive days, a period thought to be sufficient for regulatory systems to respond to the overconsumption of energy.
With the use of a crossover design, over 2 periods we served the same 5 daily menus to 46 children aged 3-5 y in their childcare centers. In 1 period, all foods and milk were served in baseline portions, and in the other period, all portions were increased by 50%. The served items were weighed to determine intake.
Increasing the portion size of all foods and milk by 50% increased daily consumption: weighed intake increased by a mean ± SEM of 143 ± 21 g/d (16%) and energy intake increased by 167 ± 22 kcal/d (18%; both P < 0.0001). The trajectories of intake by weight and energy across the 5-day period were linear and the slopes did not differ between portion conditions (both P > 0.13), indicating that there were sustained increases in intake from larger portions without compensatory changes over time. Children differed in their response to increased portions: those with higher weight status, lower ratings for satiety responsiveness, or higher ratings for food responsiveness had greater increases in intake from larger portions (all P < 0.03).
This demonstration that preschool children failed to adjust their intake during prolonged exposure to larger portions challenges the suggestion that their self-regulatory behavior is sufficient to counter perturbations in energy intake. Furthermore, overconsumption from large portions may play a role in the development of overweight and obesity, as the magnitude of the effect was greater in children of higher weight status. This trial was registered at www.clinicaltrials.gov as NCT02963987.
尽管短期研究发现，提供更大份量的食物会增加学龄前儿童的摄入量，但尚不清楚这种份量大小的影响是否能持续更长时间，或者能量摄入是否通过自我调节来调节。
我们测试了在 5 天的连续时间内，这种份量大小的影响是否能在学龄前儿童中持续存在，这一时间段被认为足以让调节系统对能量过度摄入做出反应。
我们采用交叉设计，在 2 个时期内，将相同的 5 份日常菜单提供给他们托儿中心的 46 名 3-5 岁的儿童。在一个时期内，所有的食物和牛奶都按基线份量供应，而在另一个时期，所有的份量都增加 50%。所供应的物品都经过称重以确定摄入量。
将所有食物和牛奶的份量增加 50%，增加了每日的摄入量：称重摄入量增加了 143±21 克/天（16%），能量摄入量增加了 167±22 千卡/天（18%；均 P<0.0001）。在 5 天的时间里，摄入量的轨迹呈线性，在份量条件之间，斜率没有差异（均 P>0.13），这表明，在没有时间补偿的情况下，从较大份量中摄入的量持续增加。儿童对增加份量的反应不同：体重较高、饱腹感反应评分较低或食物反应评分较高的儿童，从较大份量中摄入的量增加得更多（均 P<0.03）。
本研究表明，学龄前儿童在长时间接触较大份量时未能调整他们的摄入量，这对他们的自我调节行为足以抵消能量摄入波动的说法提出了挑战。此外，从大量食物中过度摄入可能在超重和肥胖的发展中起作用，因为体重较高的儿童的影响幅度更大。该试验在 www.clinicaltrials.gov 上注册为 NCT02963987。
