Jessri Mahsa, Lou Wendy Y, L'Abbé Mary R
Department of Nutritional Sciences, Faculty of Medicine, and.
Biostatistics Division, Dalla Lana School of Public Health, University of Toronto, Toronto, Canada.
Am J Clin Nutr. 2016 Nov;104(5):1378-1392. doi: 10.3945/ajcn.116.132647. Epub 2016 Sep 28.
Dietary pattern analysis represents a departure from the traditional focus on single foods and nutrients and provides a comprehensive understanding of the role of the diet in chronic disease prevention and etiology. Dietary patterns of Canadians have not been evaluated comprehensively with the use of an updated a priori dietary quality index.
We aimed to update the Dietary Guidelines for Americans Adherence Index (DGAI) on the basis of the 2015 Dietary Guidelines for Americans (DGA), to evaluate the construct validity and reliability of the revised index, and to examine whether closer adherence to this index is associated with a lower risk of obesity with or without an accompanying chronic disease.
Data from 11,748 participants (≥18 y of age) in the cross-sectional Canadian Community Health Survey cycle 2.2 were used in weighted multivariate analyses. Multinomial logistic regression was used to test the association between diet quality and obesity risk.
With the use of principal component analyses, the multidimensionality of the 2015 DGAI was confirmed, and its reliability was shown with a high Cronbach's α = 0.75. Moving from the first to the fourth (healthiest) quartile of the 2015 DGAI score, there was a trend toward decreased energy (2492 ± 26 compared with 2403 ± 22 kcal, respectively; ±SE) and nutrients of concern (e.g., sodium), whereas intakes of beneficial nutrients increased (P-trend < 0.05). In the age- and sex-adjusted model, a lack of adherence to the 2015 DGA recommendations increased the OR of being unhealthy obese from 1.42 (95% CI: 1.02, 1.99) in quartile 3 to 2.08 (95% CI: 1.49, 2.90) in quartile 2 to 2.31 (95% CI: 1.65, 3.23) in the first quartile of the 2015 DGAI score, compared with the fourth quartile (healthiest) (P-trend < 0.0001). The odds of being obese without a chronic disease (healthy obese) and having a chronic disease without being obese also increased in the lowest DGAI quartile compared with the highest DGAI quartile, albeit not as much as in the unhealthy obese group.
The 2015 DGAI provides a valid and reliable measure of diet quality among Canadians.
饮食模式分析与传统上对单一食物和营养素的关注不同，它能全面理解饮食在慢性病预防和病因学中的作用。尚未使用更新的先验饮食质量指数对加拿大人的饮食模式进行全面评估。
我们旨在根据《2015年美国膳食指南》（DGA）更新美国膳食指南依从性指数（DGAI），评估修订后指数的结构效度和信度，并研究更严格遵循该指数是否与较低的肥胖风险相关，无论是否伴有慢性病。
在加权多变量分析中使用了加拿大社区健康调查第2.2轮中11748名参与者（≥18岁）的数据。采用多项逻辑回归检验饮食质量与肥胖风险之间的关联。
通过主成分分析，证实了2015年DGAI的多维性，其信度较高，克朗巴哈α系数为0.75。从2015年DGAI得分的第一四分位数到第四（最健康）四分位数，能量（分别为2492±26千卡和2403±22千卡；±标准误）和相关营养素（如钠）呈下降趋势，而有益营养素的摄入量增加（P趋势<0.05）。在年龄和性别调整模型中，与第四（最健康）四分位数相比，不遵循2015年DGA建议会使不健康肥胖的比值比从第三四分位数的1.42（95%置信区间：1.02，1.99）增加到第二四分位数的2.08（95%置信区间：1.49，2.90），再到2015年DGAI得分第一四分位数的2.31（95%置信区间：1.65，3.23）（P趋势<0.0001）。与最高DGAI四分位数相比，在最低DGAI四分位数中，无慢性病的肥胖（健康肥胖）和有慢性病但不肥胖的几率也增加了，尽管增幅不如不健康肥胖组大。
2015年DGAI为加拿大人的饮食质量提供了有效且可靠的数据。
