Unravelling the ´healthy´ in a healthy lifestyle: Dietary influences on subjective wellbeing and physical health

除了有规律的体育锻炼、戒烟和适度饮酒外，饮食也是影响健康和幸福的最重要因素之一。尽管对特定形式的饮食有强烈的倡导，但还没有深入的、纵向的研究来描述饮食改变的生物和心理后果。此外，对其中介机制的研究也较少。深入研究饮食对不同身体系统的影响，包括代谢系统、神经内分泌系统和免疫系统，有望揭示饮食对健康的贡献。这项研究的目的是调查将杂食性饮食改为蛋奶素食饮食的效果，这最符合目前各种全食物饮食的建议。研究将分为两组：n=64只杂食动物参加为期2个月的蛋-奶-素食饮食干预，n=64只杂食动物继续他们的混合饮食。我们将检查参与者在干预前后的葡萄糖耐量、急性神经内分泌和炎症应激反应、基础神经内分泌功能和主观幸福感。此外，我们将在干预后的4周内对参与者进行检查，以评估他们恢复到以前的饮食行为和可能的反弹效应。我们还将采用生态学上有效的（微）纵向方法来获取饮食对健康影响的重要混杂因素的信息，如其他与健康相关的行为或干预引起的情绪和痛苦的变化。对这些机制的深入了解将有助于了解为什么素食被认为对健康有益，因此也为我们提供了潜在的新治疗目标，这将有助于开发通过饮食改善健康和预防疾病的新方法。

In addition to regular physical activity, smoking cessation and alcohol moderation, diet is among the most important influences on health and wellbeing. Despite strong advocates for particular forms of diets, there have been no in-depth, longitudinal studies characterizing the biological and psychological consequences of a change in diet. Furthermore, research on mediating mechanisms is sparse. Thorough studies of dietary influences on different bodily systems, including the metabolic system, the neuroendocrine system and the immune system, will hopefully shed light on the contribution of diet to better health. This study aims at investigating the effect of changing one's omnivorous diet to an ovo-lacto-vegetarian diet, which best complies with current recommendations of a varied whole food diet. Two groups will be examined: n=64 omnivores participating in a 2-month ovo-lacto-vegetarian dietary intervention and n=64 omnivores continuing their mixed diet. We will examine participants' glucose tolerance, acute neuroendocrine and inflammatory stress responses, basal neuroendocrine functioning, and subjective wellbeing prior to and after the intervention. Furthermore, we will examine participants throughout 4 weeks after the intervention to assess returning to previous dietary behaviour and possible rebound effects. We will also employ an ecologically valid (micro-) longitudinal approach to derive information on important confounders of dietary effects on health, such as other health-relevant behaviours or intervention-induced changes in mood and distress. A deeper understanding of these mechanisms will offer knowledge on why a vegetarian diet is assumed to be good for health, therefore also providing us with potential new treatment targets that will help in developing new approaches to improve health and prevent disease via diet.