Modeling the dynamics of human energy regulation and its implications for obesity treatment
Modeling the dynamics of human energy regulation and its implications for obesity treatment
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DOI：
10.1002/sdr.240
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发表时间：
2002-12-01
影响因子：
4.8
通讯作者：
Abdel-Hamid, TK
中科院分区：
文献类型：
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作者：
Abdel-Hamid, TK
肥胖在美国已经达到流行病的程度，并有可能成为全球流行病。更令人担忧的是，超重的发生率继续增加。对个人和社会的健康后果和经济代价是相当大的。肥胖与许多严重的健康并发症有关，包括冠心病、2型糖尿病、高血压、某些癌症和肌肉骨骼疾病。在美国，估计每年因肥胖而引致的直接及间接医疗费用接近1，000亿元。当食物和饮料形式的能量摄入与能量消耗之间存在慢性不平衡时，就会发生肥胖。迄今为止，治疗的重点一直是能量平衡方程的能量摄入方面。这在一定程度上是因为很难证明运动作为治疗策略的有效性。本文试图证明系统动力学建模的效用，研究和深入了解与体重增加和减轻有关的生理学。一个模拟模型，集成营养，新陈代谢，激素调节，身体成分，和身体活动。这些过程通常分散在许多不同的学科和概念框架之间。这项工作旨在将这些想法结合在一起，突出复杂的人体体重调节系统的各个方面的相互依赖性。该模型被用作实验工具，以调查身体活动对体重和组成的影响。这些结果重复了文献中报告的结果的“混合”，并为其变异性提供了因果解释。在一项实验中，适度的日常锻炼所带来的体重减轻与节食所带来的体重减轻相当（当两者产生相同的能量不足时）。也许更重要的是，运动干预防止了无脂肪质量的损失，这发生在仅通过节食减肥时，从而促进了身体成分的有利变化。在第二个实验中，中等强度到高强度的运动方案被证明是对肥胖久坐受试者的减肥策略起反作用的。这是由于这些人可用的能量储备有限（特别是肌糖原）。然而，当饮食从平衡的组成改变为高碳水化合物负荷的饮食时，在实验期间可以维持高强度的运动方案，并实现体重的显著下降。研究结果强调了饮食组成和身体活动之间的显著相互作用，并强调了饮食组成在基于运动的治疗干预中的关键作用。版权所有（C）2002约翰威利父子有限公司
Obesity has reached epidemic proportions in the United States and is threatening to become a global epidemic. Even more concerning, the incidence of overweight continues to increase. The health consequences and economic costs to individuals and to society are considerable. Obesity is associated with many serious health complications, including coronary heart disease, type 2 diabetes mellitus, hypertension, selected cancers, and musculoskeletal disorders. In the U.S., direct and indirect medical costs attributable to obesity are estimated to approach $100 billion yearly. Obesity develops when a chronic imbalance exists between energy intake, in the form of food and drink, and energy expenditure. To date, the emphasis of treatment has been on the energy intake side of the energy balance equation. This, in part, is because it has been difficult to demonstrate the efficacy of exercise as a treatment strategy. This paper attempts to demonstrate the utility of system dynamics modeling to study and gain insight into the physiology related to weight gain and loss. A simulation model is presented that integrates nutrition, metabolism, hormonal regulation, body composition, and physical activity. These processes are typically fragmented between many different disciplines and conceptual frameworks. This work seeks to bring these ideas together highlighting the interdependence of the various aspects of the complex human weight regulation system. The model was used as an experimentation vehicle to investigate the impacts of physical activity on body weight and composition. The results replicate the "mix" of results reported in the literature, as well as providing causal explanation for their variability. In one experiment, weight loss from a moderate level of daily exercise was comparable to the loss from dieting (when both produced equivalent energy deficits). Perhaps of greater significance, the exercise intervention protected against the loss of fat-free mass, which occurs when weight loss is achieved through dieting alone, and thus promoted favorable changes in body composition. In a second experiment, exercise regimens of moderate to high level of intensity proved counter-productive as weight-reducing strategies for an obese sedentary subject. This was due to the limited energy reserves (specifically, muscle glycogen) available to such individuals. However, when the diet was changed from a balanced composition to one that was highly loaded with carbohydrates, it became possible to sustain the intense exercise regimen over the experimental period, and achieve a significant drop in body weight. The results underscore the significant interaction effects between diet composition and physical activity, and emphasize the critical role that diet composition can have in exercise-based treatment interventions. Copyright (C) 2002 John Wiley Sons, Ltd.