Christiansen E, Garby L
Department of Mathematics and Computer Science, University of Southern Denmark, Odense, Denmark.
Eur J Clin Invest. 2002 Nov;32(11):826-30. doi: 10.1046/j.1365-2362.2002.01036.x.
Experimental difficulties have so far restricted knowledge of the effects of energy imbalance on change in body weight. Direct measurement requires that the subjects are kept under dietary supervision for several months while the activity is being measured.
The effects of energy balance can be calculated using a combination of fundamental principles and directly measurable data: the law of energy conservation (increase in combustible energy equals the difference between energy intake and energy expenditure); data on energy expenditure of fat and lean tissues; and data on the composition of added/removed tissue during weight change.
We obtained an explicit differential equation describing the development of body weight over time, with energy intake and energy expenditure as control variables. Using this model it is possible to isolate and analyse the measured effects of parameters not included in the model, such as age or 'adaptivity' of the body.
迄今为止，实验困难限制了我们对能量失衡对体重变化影响的了解。直接测量要求受试者在测量活动期间接受数月的饮食监督。
能量平衡的影响可以通过结合基本原理和直接可测量的数据来计算：能量守恒定律（可燃能量的增加等于能量摄入与能量消耗之间的差值）；脂肪和瘦组织的能量消耗数据；以及体重变化期间添加/去除组织的组成数据。
我们得到了一个明确的微分方程，描述了体重随时间的变化，将能量摄入和能量消耗作为控制变量。使用这个模型，可以分离和分析模型中未包含的参数的测量效应，如年龄或身体的“适应性”。
