College of Science and Mathematics, Department of Biology and Physical Education, Norwich University, Northfield, VT 05663, United States.
Physiol Behav. 2013 Oct 2;122:8-16. doi: 10.1016/j.physbeh.2013.08.001. Epub 2013 Aug 22.
A unifying physiological explanation of the urge to initiate eating is still not available as human hunger in meal-to-meal eating may not be under homeostatic control. We hypothesized that a central circadian and a gastrointestinal ultradian timing mechanism coordinate non-deprivation meal-to-meal eating. We examined hunger as a function of time of day, inter-meal (IM) energy expenditure (EE), and concentrations of proposed hunger-controlling hormones ghrelin, leptin, and insulin.
In two crossover studies, 10 postmenopausal women, BMI 23-26 kg/m(2) engaged in exercise (EX) and sedentary (SED) trials. Weight maintenance meals were provided at 6h intervals with an ad libitum meal at 13 h in study 1 and 21 h snack in study 2. EE during IM intervals was measured by indirect calorimetry and included EX EE of 801 kcal in study 1, and 766-1,051 kcal in study 2. Hunger was assessed with a visual analog scale and blood was collected for hormonal determination.
Hunger displayed a circadian variation with acrophase at 13 and 19 h and was unrelated to preceding EE. Hunger was suppressed by EX between 10 and 16 h and bore no relationship to either EE during preceding IM intervals or changes in leptin, insulin, and ghrelin; however leptin reflected IM energy changes and ghrelin and insulin, prandial events.
During non-deprivation meal-to-meal eating, hunger appears to be under non-homeostatic central circadian control as it is unrelated to EE preceding meals or concentrations of proposed appetite-controlling hormones. Gastrointestinal meal processing appears to intermittently suppress this control and entrain an ultradian hunger pattern.
目前仍缺乏一种能够统一解释进食欲望的生理学理论，因为人类在进食过程中的饥饿感可能不受体内平衡控制。我们假设中枢昼夜节律和胃肠道超日周期计时机制共同协调非剥夺性的进食间进食。我们研究了饥饿感与时间、进食间能量消耗（EE）以及推测控制饥饿感的激素——胃饥饿素、瘦素和胰岛素的浓度之间的关系。
在两项交叉研究中，10 名绝经后女性（BMI 23-26kg/m2）参与了运动（EX）和静坐（SED）试验。每 6 小时提供一次维持体重的膳食，并在研究 1 中于 13 小时提供一份随意的膳食，在研究 2 中于 21 小时提供一份零食。通过间接测热法测量进食间的 EE，其中研究 1 的 EX EE 为 801kcal，研究 2 为 766-1051kcal。通过视觉模拟量表评估饥饿感，并采集血液用于激素测定。
饥饿感呈现出昼夜节律变化，峰值出现在 13 小时和 19 小时，与之前的 EE 无关。EX 在 10 点至 16 点之间抑制了饥饿感，与之前进食间的 EE 或瘦素、胰岛素和胃饥饿素的变化无关；然而，瘦素反映了进食间的能量变化，而胃饥饿素和胰岛素则反映了进食事件。
在非剥夺性的进食间进食期间，饥饿感似乎受到非体内平衡的中枢昼夜节律控制，与之前的膳食 EE 或拟议的食欲控制激素的浓度无关。胃肠道的膳食处理似乎间歇性地抑制了这种控制，并使超日周期的饥饿模式得以形成。
