Flickr: Jesse Garrison

对环境造成的影响

“你就是你吃的东西” - 为了健康和健康而需要吃美食的概念在更广泛的规模上获得了意义。尽管良好的饮食选择可以增强自己的健康，但它们也可以使地球受益。饮食指南通常为摄入动物产品提供定量建议。但是，鉴于越来越多的肉类饮食减少肉类的影响，消费者对与肉类生产相关的环境影响变得更加关注。

Raising animals for food requires enormous amounts of land, food, energy, and water and causes animal suffering. According to areport由Worldwatch Institute出版，全球51％或更多的全球温室气体排放是由动物农业引起的。在过去的15年中，欧盟的肉类消费量已减少和稳定在约4200万吨，而在欧洲和美国，无麸质产品的数量增加了一倍，植物的消费量增加了豆类和小扁豆的蛋白质。

诸如“您不能成为吃肉的环保主义者”之类的强烈主张刺激了素食主义者和肉食者之间的争议，但越来越多的人试图对饮食进行重大改变。新标签，例如“ Flexitarians”（有时只吃肉）和“减少肉类”（旨在减少肉类），这表明不同的人如何努力以一种或另一种方式减少他们的肉类消耗。

The conscious customer

So how do consumers choose their foods when they have to consider dietary guidelines as well as the potential environmental impact of their purchasing behaviors?

A largestudypublished yesterday inBMC Public Health是第一个在购买动物食品时第一个研究健康和环境考虑之间潜在困境的人。该研究的作者专门研究了购买肉类，鱼类和乳制品时报告健康和环境困境的个人的社会人口统计学特征，并比较有和没有困境的人的饮食质量。

The cross-sectional study involves 22,936 subjects from the NutriNet-Santé cohort study. Volunteers were recruited via multimedia campaigns and completed a set of self-administered, web-based questionnaires assessing dietary intake, physical activity, anthropometric characteristics, lifestyle, socioeconomic conditions and health status. At inclusion and once a year thereafter, participants were invited to complete three non-consecutive 24-h dietary records, which were validated against urinary biomarkers. In order for a dilemma to be assessed, participants were asked to rate items on a 4-point Likert scale: strongly disagree/disagree/agree/strongly agree to statements including: “I purchase [meat/fish/dairy products] for health issues.”

Results of the study show that around 10% of individuals are torn between health and environmental considerations when purchasing meat or fish, and this is the case for only 5% for dairy products. Older participants, women, and low income individuals are more likely to report facing this dilemma. Participants who report dilemmas for meat and dairy products consume less of these foods and have a better dietary quality overall. In addition, participants with a meat dilemma show better adherence to meat/fish/eggs guidelines.

Sustainability and the way forward

The results of this study indicate that having environmental concerns is not contradictory to adherence with nutritional guidelines. National dietary guidelines should therefore be adapted to take into account both health and environmental sustainability as we are already seeing in some countries, such as Germany, where dilemmas in food choice will probably be lower.

As we cannot say with certainty that eating a vegetarian diet is any better for the environment, we do need to acknowledge and understand that there are trade-offs in what foods we choose to eat. For example, flying in green beans from Kenya to the UK may be seen as unsustainable due to air miles, but it also supports up to 1.5 million people in some of the poorest regions of Sub-Saharan Africa.

Ultimately though, if you are contributing to food waste, then your diet is unsustainable regardless of whether you are a vegan, vegetarian, or a meat eater.