Abstract：
OBJECTIVE: Evaluate the validity of the PortionSize application.
METHODS: In this pilot study, 14 adults used PortionSize to record their free-living food intake over 3 consecutive days. Digital photography was the criterion measure, and the main outcomes were estimated intake of food (grams), energy (kilocalories), and food groups. Equivalence tests with ±25% equivalence bounds and Bland-Altman analysis were performed.
RESULTS: Estimated gram intake from PortionSize was equivalent (P < 0.001) to digital photography estimates. PortionSize and digital photography estimated energy intake, however, were not equivalent (P = 0.08), with larger estimates from PortionSize. In addition, PortionSize and digital photography were equivalent for vegetable intake (P = 0.01), but PortionSize had larger estimates of fruits, grains, dairy, and protein intake (P >0.07; error range 11% to 23%).
CONCLUSIONS: Compared with digital photography, PortionSize accurately estimated food intake and had reasonable error rates for other nutrients; however, it overestimated energy intake, indicating further application improvements are needed for free-living conditions.
METHODS: In this pilot study, 14 adults used PortionSize to record their free-living food intake over 3 consecutive days. Digital photography was the criterion measure, and the main outcomes were estimated intake of food (grams), energy (kilocalories), and food groups. Equivalence tests with ±25% equivalence bounds and Bland-Altman analysis were performed.
RESULTS: Estimated gram intake from PortionSize was equivalent (P < 0.001) to digital photography estimates. PortionSize and digital photography estimated energy intake, however, were not equivalent (P = 0.08), with larger estimates from PortionSize. In addition, PortionSize and digital photography were equivalent for vegetable intake (P = 0.01), but PortionSize had larger estimates of fruits, grains, dairy, and protein intake (P >0.07; error range 11% to 23%).
CONCLUSIONS: Compared with digital photography, PortionSize accurately estimated food intake and had reasonable error rates for other nutrients; however, it overestimated energy intake, indicating further application improvements are needed for free-living conditions.
摘要：
目的：评估PortionSize应用的有效性。
方法：在这项试点研究中，14名成年人使用PortionSize记录他们连续3天的自由生活食物摄入量。数字摄影是标准措施，主要结果是估计食物摄入量(克)，能量（千卡）,和食物组。进行了具有±25％等效界限的等效测试和Bland-Altman分析。
结果：来自PortionSize的估计克摄入量与数字摄影估计相当（P<0.001）。PortionSize和数码摄影估计的能量摄入，然而,不相等(P=0.08)，PortionSize的估计更大。此外,份量和数码摄影与蔬菜摄入量相当(P=0.01)，但是PortionSize对水果的估计更大，谷物,乳制品，和蛋白质摄入量（P>0.07；误差范围为11％至23％）。
结论：与数码摄影相比，PortionSize准确地估计了食物摄入量，并且对其他营养素有合理的错误率；然而，它高估了能量摄入，表明自由生活条件需要进一步改善应用。
方法：在这项试点研究中，14名成年人使用PortionSize记录他们连续3天的自由生活食物摄入量。数字摄影是标准措施，主要结果是估计食物摄入量(克)，能量（千卡）,和食物组。进行了具有±25％等效界限的等效测试和Bland-Altman分析。
结果：来自PortionSize的估计克摄入量与数字摄影估计相当（P<0.001）。PortionSize和数码摄影估计的能量摄入，然而,不相等(P=0.08)，PortionSize的估计更大。此外,份量和数码摄影与蔬菜摄入量相当(P=0.01)，但是PortionSize对水果的估计更大，谷物,乳制品，和蛋白质摄入量（P>0.07；误差范围为11％至23％）。
结论：与数码摄影相比，PortionSize准确地估计了食物摄入量，并且对其他营养素有合理的错误率；然而，它高估了能量摄入，表明自由生活条件需要进一步改善应用。
