Chaput Jean-Philippe, Tremblay Angelo
Division of Kinesiology (PEPS), Department of Social and Preventive Medicine, Faculty of Medicine, Laval University, Sainte-Foy, Québec, Canada G1K 7P4.
Physiol Behav. 2007 Jan 30;90(1):66-72. doi: 10.1016/j.physbeh.2006.08.030. Epub 2006 Oct 3.
The aim of this study was to evaluate the impact of knowledge-based work (KBW) on feeding behavior and spontaneous energy intake with the use of a repeated measures/within-subjects design. We used a two-session protocol including an ad libitum buffet preceded by either rest in a sitting position for 45 min or a cognitive task (reading a document and writing a summary of 350 words using a computer) over the same time period. In this regard, 15 healthy Laval University female students (mean age = 24.1+/-2.2 years, mean BMI = 24.0+/-4.3 kg/m2) were recruited to participate in this study. Anthropometric variables, energy expenditure, heart rate, blood pressure, food intake (dietary record), and appetite sensation markers were measured at each testing session, and two questionnaires [Three-Factor Eating Questionnaire (TFEQ) and State-Trait Anxiety Inventory (STAI)] were administered. In addition, a buffet-type meal was used to measure spontaneous energy intake and macronutrient preferences. We found that the mean energy expenditure of the two conditions was about comparable (difference of 13 kJ between the two tasks) whereas the mean ad libitum energy intake after the KBW task exceeded that measured after rest by 959 kJ (p < 0.01). Although a higher absolute energy intake was observed for the three macronutrients after the KBW task (p < 0.05), no specific preference was detected, as reflected by the comparable percent of energy from each macronutrient in the two conditions. No significant difference in appetite sensation markers was observed between the two conditions, although the subjects ate more in the buffet-type meal after the KBW task. Furthermore, the subjects did not compensate by decreasing food intake for the rest of the day, suggesting a net caloric surplus. We also observed negative correlations between cognitive dietary restraint (TFEQ) and spontaneous energy intake in both conditions. In conclusion, our results demonstrate that mental work solicited by KBW has the potential to induce a higher spontaneous energy intake. This also raises the possibility that KBW adds a new component to sedentariness that might further accentuate the positive energy balance that is more likely to occur when one is inactive.
本研究旨在采用重复测量/被试内设计，评估基于知识的工作（KBW）对进食行为和自发能量摄入的影响。我们采用了两阶段方案，包括在自由进食自助餐之前，让被试在相同时间段内要么坐着休息45分钟，要么进行一项认知任务（阅读一份文件并使用电脑撰写一篇350字的摘要）。在这方面，招募了15名健康的拉瓦尔大学女学生（平均年龄 = 24.1±2.2岁，平均BMI = 24.0±4.3kg/m²）参与本研究。在每个测试阶段测量人体测量学变量、能量消耗、心率、血压、食物摄入量（饮食记录）和食欲感觉标志物，并发放两份问卷[三因素饮食问卷（TFEQ）和状态-特质焦虑量表（STAI）]。此外，使用自助餐类型的餐食来测量自发能量摄入和宏量营养素偏好。我们发现，两种条件下的平均能量消耗大致相当（两项任务之间相差13kJ），而KBW任务后的自由能量摄入量平均比休息后测量的超出959kJ（p < 0.01）。尽管在KBW任务后三种宏量营养素的绝对能量摄入量更高（p < 0.05），但未检测到特定偏好，这从两种条件下每种宏量营养素能量百分比相当可以看出。两种条件下食欲感觉标志物没有显著差异，尽管被试在KBW任务后的自助餐类型餐食中吃得更多。此外，被试在当天剩余时间没有通过减少食物摄入量来进行补偿，表明存在净热量盈余。我们还观察到，在两种条件下，认知性饮食克制（TFEQ）与自发能量摄入之间均呈负相关。总之，我们的结果表明，KBW引发的脑力工作有可能导致更高的自发能量摄入。这也增加了一种可能性，即KBW为久坐不动增添了一个新因素，这可能会进一步加剧在不活动时更易出现的正能量平衡。
