Gillies Nicola A, Worthington Anna, Li Larissa, Conner Tamlin S, Bermingham Emma N, Knowles Scott O, Cameron-Smith David, Hannaford Rina, Braakhuis Andrea
Discipline of Nutrition, School of Medical Sciences, Faculty of Medical and Health Sciences, The University of Auckland, Auckland, New Zealand.
Department of Psychology, University of Otago, Dunedin, New Zealand.
Front Nutr. 2023 Jun 14;10:1174726. doi: 10.3389/fnut.2023.1174726. eCollection 2023.
Flexitarian, vegetarian and exclusively plant-based diets are increasingly popular, particularly amongst young adults. This is the first randomised dietary intervention to investigate the health, wellbeing, and behavioural implications of consuming a basal vegetarian diet that additionally includes low-to-moderate amounts of red meat (flexitarian) compared to one containing plant-based meat alternatives (PBMAs, vegetarian) in young adults (ClinicalTrials.gov NCT04869163). The objective for the current analysis is to measure adherence to the intervention, nutrition behaviours, and participants' experience with their allocated dietary group.
Eighty healthy young adults participated in this 10-week dietary intervention as household pairs. Household pairs were randomised to receive either approximately three serves of red meat (average of 390 g cooked weight per individual, flexitarian group) or PBMAs (350-400 g per individual, vegetarian group) per week on top of a basal vegetarian diet. Participants were supported to adopt healthy eating behaviours, and this intervention was developed and implemented using a behaviour change framework. Adherence (eating allocated red meat or PBMA, abstaining from animal-based foods not provided by researchers) was continuously monitored, with total scores calculated at the end of the 10-week intervention period. Eating experiences were measured by the Positive Eating Scale and a purpose-designed exit survey, and a food frequency questionnaire measured dietary intake. Analyses used mixed effects modeling taking household clustering into account.
The total average adherence score was 91.5 (SD = 9.0) out of a possible 100, with participants in the flexitarian group scoring higher (96.1, SD = 4.6, compared to 86.7, SD = 10.0; < 0.001). Those receiving red meat were generally more satisfied with this allocation compared to those receiving the PBMAs, even though a leading motivation for participants joining the study was an opportunity to try plant-based eating (35% expressed that their interest in taking part was related to trying plant-based eating). Participants in both intervention groups had increased vegetable intake ( < 0.001), and reported more positive eating experiences ( = 0.020) and satisfaction with eating ( = 0.021) at the end of the 10-week intervention relative to baseline values.
Methods to encourage engagement with the trial were successful, as participants demonstrated excellent adherence to the intervention. Observed differences in participants' adherence and experiences between flexitarian and vegetarian groups holds implications for the adoption of healthy, sustainable dietary patterns beyond this study alone.
弹性素食、素食和纯植物性饮食越来越受欢迎，尤其是在年轻人中。这是第一项随机饮食干预研究，旨在调查与食用含植物性肉类替代品（PBMA，素食组）的基础素食相比，年轻人食用额外包含少量至适量红肉的基础素食（弹性素食）对健康、幸福感和行为的影响（ClinicalTrials.gov NCT04869163）。本次分析的目的是衡量对干预措施的依从性、营养行为以及参与者在其分配的饮食组中的体验。
80名健康的年轻人以家庭对的形式参与了这项为期10周的饮食干预。家庭对被随机分配，在基础素食之上，每周接受大约三份红肉（每人平均煮熟重量390克，弹性素食组）或PBMA（每人350 - 400克，素食组）。支持参与者采用健康的饮食行为，并且该干预措施是使用行为改变框架制定和实施的。持续监测依从性（食用分配的红肉或PBMA，不食用研究人员未提供的动物性食物），在10周干预期结束时计算总分。通过积极饮食量表和专门设计的退出调查问卷来衡量饮食体验，通过食物频率问卷来衡量饮食摄入量。分析采用考虑家庭聚类的混合效应模型。
在满分100分中，总平均依从性得分为91.5（标准差 = 9.0），弹性素食组的参与者得分更高（96.1，标准差 = 4.6，而素食组为86.7，标准差 = 10.0；<0.001）。与接受PBMA的人相比，接受红肉的人通常对这种分配更满意，尽管参与者参与该研究的一个主要动机是有机会尝试植物性饮食（35%表示他们参与的兴趣与尝试植物性饮食有关）。与基线值相比，两个干预组的参与者在10周干预结束时蔬菜摄入量均有所增加（<0.001），并且报告了更积极的饮食体验（=0.020）和对饮食的满意度（=0.021）。
鼓励参与试验的方法是成功的，因为参与者对干预措施表现出了出色的依从性。弹性素食组和素食组参与者在依从性和体验方面观察到的差异，对于仅在本研究之外采用健康、可持续的饮食模式具有启示意义。
