Institute of Psychology, Health, and Society, University of Liverpool, Liverpool, United Kingdom.
Am J Clin Nutr. 2018 Apr 1;107(4):640-646. doi: 10.1093/ajcn/nqy013.
Historical increases in the size of commercially available food products have been linked to the emergence of a worldwide obesity crisis. Although the acute effect that portion size has on food intake is well established, the effect that exposure to smaller portion sizes has on future portion size selection has not been examined.
We tested whether reducing a food portion size "renormalizes" perceptions of what constitutes a normal amount of that food to eat and results in people selecting and consuming smaller portions of that food in the future.
Across 3 experiments, participants were served a larger or smaller portion of food. In experiments 1 and 2, participants selected and consumed a portion of that food 24 h later. In experiment 3, participants reported on their preferred ideal portion size of that food after 1 wk.
The consumption of a smaller, as opposed to a larger, portion size of a food resulted in participants believing a "normal"-sized portion was smaller (experiments 1-3, P ≤ 0.001), consuming less of that food 1 d later (experiments 1-2, P ≤ 0.003), and displaying a tendency toward choosing a smaller ideal portion of that food 1 wk later (experiment 3, P = 0.07), although the latter finding was not significant.
Because consumer preferences appear to be driven by environmental influences, reducing food portion sizes may recalibrate perceptions of what constitutes a "normal" amount of food to eat and, in doing so, decrease how much consumers choose to eat. This trial was registered at www.clinicaltrials.gov as NCT03241576.
商业销售的食品尺寸增大与全球肥胖危机的出现有关。尽管食物份量对食物摄入量的急性影响已得到充分证实，但暴露于较小份量对未来份量选择的影响尚未得到检验。
我们检验食物份量减少是否“使正常食量的感知正常化”，并导致人们在未来选择和食用较小份量的食物。
在 3 项实验中，参与者食用了较大或较小份量的食物。在实验 1 和 2 中，参与者在 24 小时后选择并食用了部分食物。在实验 3 中，参与者在 1 周后报告了他们对该食物理想份量的偏好。
与食用较大份量相比，食用较小份量的食物会导致参与者认为“正常”份量较小（实验 1-3，P≤0.001），1 天后食用的量更少（实验 1-2，P≤0.003），并且在 1 周后选择较小理想份量的趋势更大（实验 3，P=0.07），尽管后一种发现并不显著。
由于消费者偏好似乎受环境影响驱动，减少食物份量可能会重新校准对“正常”食量的感知，从而减少消费者的选择量。本试验已在 www.clinicaltrials.gov 上注册，编号为 NCT03241576。
