ENVIRONMENTAL INFLUENCES ON FOOD INTAKE AND OBESITY

有人认为，食物份量的增加导致了能量摄入过剩，从而导致了肥胖发病率的上升。然而，很少有研究调查份量大小和食物摄入量之间的关系。很可能是消费者的特点，以及所吃食物的类型，可能会影响份量对能量平衡的影响。食物的能量密度（每克千卡）也可能对份量大小的反应产生重大影响。如果能量密度和分量大小相互作用影响摄入，这将支持一种假设，即大量高能量密度的食物在促进过量能量摄入方面起着重要作用。另一方面，如果增加低能量密度食物的份量也会影响食用量，这将建议减少能量摄入的策略。为了解决这些问题，提出了四个高度控制的实验室实验。实验1a、1b和2将测试逐渐增加三种不同食物的分量对能量摄入的影响。实验3将通过使用在这两个因素上有系统变化的配方食品来研究份量和能量密度之间的相互作用。实验四将测试在两天内增加所有食物的分量，包括高能量密度和低能量密度的食物的影响。这些研究将解决以下具体目标：1)确定增加不同类型食物的份量对能量摄入的影响；2)确定调节份量对摄入量影响的个体特征；3)确定份量大小和能量密度如何相互作用影响摄入量；4)确定在两天内增加所有食物的份量对能量摄入的影响。拟议的研究将提供关于份量大小对不同类型食物摄入量的影响的基本数据，以及可能对这种影响最敏感的个体。这些数据对于制定有效的体重管理策略至关重要，这些策略包括份量对能量摄入的影响。

It has been suggested that increases in the portion size of foods have contributed to excess energy intakes and thus the growing incidence of obesity. Few studies, however, have examined the relationship between portion size and food intake. It is probable that characteristics of the consumer, as well as of the type of food eaten, may influence how portion size affects energy balance. The energy density of foods (kcal per gram) is also likely to have a significant impact on the response to portion size. If energy density and portion size interact to affect intake, this will support the hypothesis that large portions of foods high in energy density have a major role in promoting excess energy intake. On the other hand, if increasing the portions of foods low in energy density also affects the amount eaten, this would suggest a strategy for reducing energy intake. To address these issues, four highly-controlled laboratory experiments are proposed. Experiments 1a, 1b, and 2 will test the effect on energy intake of incrementally increasing the portions of three different foods. Experiment 3 will investigate the interaction between portion size and energy density by using formulated foods which systematically vary in these two factors. Experiment 4 will test the impact of increasing the portions of all foods offered, both those high and low in energy density, over a two-day period. These studies will address the following specific aims: 1) to determine the effect on energy intake of increasing the portion size of different types of foods; 2) to identify characteristics of individuals which modulate the effect of portion size on intake; 3) to determine how portion size and energy density interact to influence intake; and 4) to determine the effect on energy intake of increasing the portion size of all foods served over two days. The proposed studies will provide fundamental data about the effect of portion size on intake of different types of foods, and about individuals likely to be most responsive to this effect. These data are critical for the development of effective strategies for weight management that incorporate the influence of portion size on energy intake.