Hays Nicholas P, Roberts Susan B
Nutrition, Metabolism, and Exercise Laboratory, Donald W. Reynolds Institute on Aging, University of Arkansas for Medical Sciences, Geriatric Research, Education, and Clinical Center, Little Rock 72205, USA.
Physiol Behav. 2006 Jun 30;88(3):257-66. doi: 10.1016/j.physbeh.2006.05.029.
Energy intake is reduced in older individuals, with several lines of evidence suggesting that both physiological impairment of food intake regulation and non-physiological mechanisms are important. Non-physiological causes of the anorexia of aging include social (e.g. poverty, isolation), psychological (e.g. depression, dementia), medical (e.g. edentulism, dysphagia), and pharmacological factors. Physiological factors include changes in taste and smell, diminished sensory-specific satiety, delayed gastric emptying, altered digestion-related hormone secretion and hormonal responsiveness, as well as food intake-related regulatory impairments for which specific mechanisms remain largely unknown. Studies in healthy elderly individuals have shown that men who consume diets over several weeks providing either too few or too many calories relative to dietary energy needs subsequently do not compensate for the resulting energy deficit or surplus when provided an ad libitum diet. Healthy elders have also been shown to be less hungry at meal initiation and to become more rapidly satiated during a standard meal compared to younger adults. Studies in animal models are required to investigate potential mechanisms underlying these observations, while human studies should focus on examining the potential consequences of this phenomenon and practical therapeutic strategies for the maintenance of appropriate energy intake with increasing age. In light of this need, we have recently demonstrated that low reported hunger assessed using a simple questionnaire predicts unintentional weight loss in a sample of healthy older women, and thus may provide a clinically useful tool for identifying older individuals at risk for undesirable weight change and therefore at high priority for intervention.
老年人的能量摄入会减少，有几条证据表明食物摄入调节的生理损伤和非生理机制都很重要。衰老性厌食的非生理原因包括社会因素（如贫困、孤独）、心理因素（如抑郁、痴呆）、医学因素（如无牙、吞咽困难）和药物因素。生理因素包括味觉和嗅觉的变化、特定感觉饱腹感的降低、胃排空延迟、消化相关激素分泌和激素反应性的改变，以及食物摄入相关的调节障碍，而其具体机制在很大程度上仍不清楚。对健康老年人的研究表明，在数周内摄入的饮食相对于饮食能量需求而言热量过少或过多的男性，在改为自由进食饮食后，随后无法弥补由此产生的能量不足或过剩。与年轻人相比，健康老年人在开始用餐时也表现出较低的饥饿感，并且在标准餐期间更快产生饱腹感。需要通过动物模型研究来探究这些观察结果背后的潜在机制，而人体研究应侧重于检查这一现象的潜在后果以及随着年龄增长维持适当能量摄入的实际治疗策略。鉴于这一需求，我们最近证明，使用简单问卷评估得出的低饥饿感报告可预测健康老年女性样本中的非故意体重减轻，因此可能为识别有体重意外变化风险的老年人提供一种临床有用工具，从而确定其为干预的高度优先对象。
