Adults adopt a vegetarian diet for various motivations, but it is unknown their overall diet quality based on a primary motivation. The purpose of the study was to compare overall diet quality, nutrient intake and related food groups based on primary motivation for following a vegetarian diet. It was hypothesized that vegetarians who chose the diet for health-related motivations would have a higher diet quality based on the Healthy Eating Index (HEI)-2015 scores compared to those following the diet for other motivations. A cross-sectional study was conducted online in the United States. Participants (n = 511) completed an 18-item questionnaire and a 24-hour recall using the Automated Self-Administered 24-hour Dietary Recall (ASA24-2018) and were divided into one of three groups (Health, Animal, Other [family, religious beliefs, or environment]) based on their primary motivation for following a vegetarian diet. Total HEI-2015 scores were determined and Kruskal-Wallis ANOVA on Ranks with a Dunn's Method for all pairwise comparisons (p < 0.05) were conducted. Results showed that total HEI-2015 scores differed among groups (p = 0.022) with the Health group having a higher score than the Other group (70.2 [57.0, 79.1] versus 63.6 [52.2, 77.1], median 25th, 75th) but not the animal rights group (66.5 [55.1, 77.0]). Higher component scores for total protein foods, seafood and plant proteins and fatty acids contributed to the significant difference. Adults who were motivated by health to follow a vegetarian diet had a higher diet quality than those who cited Other as their primary motivation. As motivations may impact diet quality of vegetarians, it is necessary to account for them.

成年人出于各种动机而采用素食，但基于主要动机，他们的整体饮食质量尚不清楚。该研究的目的是基于遵循素食的主要动机来比较整体饮食质量、营养摄入和相关食物组。根据健康饮食指数 (HEI)-2015 分数，假设出于健康相关动机选择饮食的素食者与出于其他动机选择饮食的素食者相比，其饮食质量更高。一项横断面研究在美国在线进行。参与者 (n = 511) 使用自动自我管理的 24 小时饮食回忆 (ASA24-2018) 完成了 18 项问卷和 24 小时回忆，并被分为三组（健康、动物、其他 [家庭] ， 宗教信仰，或环境]）基于他们遵循素食的主要动机。确定了 HEI-2015 总分，并使用 Dunn 方法对所有成对比较 (p < 0.05) 进行了 Kruskal-Wallis 方差分析。结果显示，各组之间的 HEI-2015 总分存在差异 (p = 0.022)，其中健康组的得分高于其他组（70.2 [57.0, 79.1] 对 63.6 [52.2, 77.1]，中位数第 25、第 75）但不是动物权利组织（66.5 [55.1, 77.0]）。总蛋白食物、海鲜和植物蛋白以及脂肪酸的较高成分得分导致了显着差异。出于健康动机而遵循素食的成年人的饮食质量高于那些将其他作为主要动机的成年人。由于动机可能会影响素食者的饮食质量，