Thomas Diana M, Paynter Jonathan, Peterson Courtney M, Heymsfield Steven B, Nduati Ann, Apolzan John W, Martin Corby K
US Military Academy, West Point, NY;
US Military Academy, West Point, NY.
Am J Clin Nutr. 2017 Feb;105(2):323-331. doi: 10.3945/ajcn.115.127811. Epub 2017 Jan 11.
Attempts to model cumulative intake curves with quadratic functions have not simultaneously taken gustatory stimulation, satiation, and maximal food intake into account.
Our aim was to develop a dynamic model for cumulative intake curves that captures gustatory stimulation, satiation, and maximal food intake.
We developed a first-principles model describing cumulative intake that universally describes gustatory stimulation, satiation, and maximal food intake using 3 key parameters: 1) the initial eating rate, 2) the effective duration of eating, and 3) the maximal food intake. These model parameters were estimated in a study (n = 49) where eating rates were deliberately changed. Baseline data was used to determine the quality of model's fit to data compared with the quadratic model. The 3 parameters were also calculated in a second study consisting of restrained and unrestrained eaters. Finally, we calculated when the gustatory stimulation phase is short or absent.
The mean sum squared error for the first-principles model was 337.1 ± 240.4 compared with 581.6 ± 563.5 for the quadratic model, or a 43% improvement in fit. Individual comparison demonstrated lower errors for 94% of the subjects. Both sex (P = 0.002) and eating duration (P = 0.002) were associated with the initial eating rate (adjusted R = 0.23). Sex was also associated (P = 0.03 and P = 0.012) with the effective eating duration and maximum food intake (adjusted R = 0.06 and 0.11). In participants directed to eat as much as they could compared with as much as they felt comfortable with, the maximal intake parameter was approximately double the amount. The model found that certain parameter regions resulted in both stimulation and satiation phases, whereas others only produced a satiation phase.
The first-principles model better quantifies interindividual differences in food intake, shows how aspects of food intake differ across subpopulations, and can be applied to determine how eating behavior factors influence total food intake.
用二次函数对累积摄入量曲线进行建模的尝试尚未同时考虑味觉刺激、饱腹感和最大食物摄入量。
我们的目标是开发一种用于累积摄入量曲线的动态模型，该模型能够捕捉味觉刺激、饱腹感和最大食物摄入量。
我们开发了一个基于第一原理的模型来描述累积摄入量，该模型使用3个关键参数普遍描述味觉刺激、饱腹感和最大食物摄入量：1）初始进食速率，2）有效进食持续时间，3）最大食物摄入量。在一项研究（n = 49）中对这些模型参数进行了估计，在该研究中进食速率被有意改变。与二次模型相比，基线数据用于确定模型对数据的拟合质量。在第二项由节制饮食者和非节制饮食者组成的研究中也计算了这3个参数。最后，我们计算了味觉刺激阶段较短或不存在的情况。
与二次模型的平均平方和误差581.6±563.5相比，基于第一原理的模型的平均平方和误差为337.1±240.4，拟合度提高了43%。个体比较显示94%的受试者误差更低。性别（P = 0.002）和进食持续时间（P = 0.002）均与初始进食速率相关（调整后R = 0.23）。性别也与有效进食持续时间和最大食物摄入量相关（P = 0.03和P = 0.012）（调整后R = 0.06和0.11）。与按舒适量进食的参与者相比，被要求尽可能多吃的参与者的最大摄入量参数约为其两倍。该模型发现，某些参数区域会导致刺激阶段和饱腹感阶段，而其他区域仅产生饱腹感阶段。
基于第一原理的模型能更好地量化个体间食物摄入量的差异，显示不同亚人群食物摄入量的差异，并可用于确定饮食行为因素如何影响总食物摄入量。
