Healthy diets and sustainability

Healthy diets and sustainability by Fiona Graham

Grantham Scholar Fiona Graham introduces the complexities of healthy diets and sustainability, including the difficulty of good data and unforeseen impacts. 

Grantham Scholar Fiona Graham.
Grantham Scholar Fiona Graham.

For Journal Club I chose to introduce the article Global diets link environmental sustainability and human health. This paper discusses the environmental impact of food production. I hoped it would place my project, Reducing environmental impacts through sustainable food choice, in context. And that it would provide the Scholars with an insight into some of the approaches used in my field.

Global diets link environmental sustainability and human health

Published in Nature in 2014, the paper draws together data about the impact the global transition to diets high in processed foods, meat and animal products has on human health and the environment.

Also, the paper compares the impacts of food types in terms of their greenhouse gas emissions (GHGE). Plus it compiles data to compare the differences in health indicators for range of alternative diets: Mediterranean, pescatarian and vegetarian.

A discussion about the environmental impact of food

The reaction to the paper was positive. Most Scholars found it accessible and relevant to their research.

Many were aware that ruminant meat production produces the most GHGE. But the Scholars were surprised by how high the carbon emissions were for fish, specifically the differences between different fishing practices.

Carbon emissions

Scholars noted that the paper only focused on the GHGE of food production.

It did not examine other environmental impacts such as water use and land degradation. We talked about why carbon emissions were the focus of the paper.

In the end, we decided that this was probably the most straightforward impact to measure, though other impacts should not be neglected.

What is a sustainable diet?

This led to a broader discussion around the concept of a ‘sustainable diet’.

It was acknowledged that when defining sustainable diets it is important to consider more than their environmental impact. Because we also need to bear in mind the social and economic impacts they have in terms of health, culture and identity, jobs, trade and labour conditions etc. Encompassing all these factors is a huge challenge for those striving to achieve a sustainable food system.

The paper indicated that different dietary choices connect environmental sustainability and human health. However, we, and the authors of the paper, were undecided as to what diet should be advocated. For example, Scholars noted that a pescatarian diet may be healthier and have fewer carbon emissions than an omnivorous diet. But if this diet were to be adopted by a larger proportion of the population it would have a detrimental impact on fish stocks.

Life Cycle Assessment

Life Cycle Assessment (LCA) is an approach used to measure the environmental impacts of a product from its ‘cradle to grave’ and one being considered in my own research.

In relation to the paper, we asked if the data presented captures the full extent of the environmental impact of food production. It doesn’t include information about the environmental impact of the food supply beyond the farm. For example, emissions associated with the transport, processing, storage and cooking of the food. Nor does it include emissions associated with food waste.

The authors imply that this information was not included due to a lack of data. Scholars agreed that until more data is available, or a new method for measuring the environmental impact of food production is devised, the conclusions drawn from LCA studies should be interpreted with caution.

How best to communicate with consumers

Can we convey a clear message to consumers given the multiple environmental impacts associated with each food item?

Multiple factors influence food choices. Would environmental damage influence choice at all, compared to other factors e.g. taste and cost?

Scholars reflected on the recent Fabian Commission on Food and Poverty hearing hosted by the Grantham Centre, which considered how dietary change in the UK may be brought about.

We need healthy diets and sustainability

Overall, we were in agreement that dietary change is needed given the impacts current dietary trends are having on health and the environment.

However, it is not clear what this change might look like. The paper was careful not to advocate one diet over another. Instead it sparked debate around alternative diets and whether they posed plausible solutions to the diet-health-environment problem.

Our discussion highlighted the complexity of this global challenge. And the multiple interactions within the food system that shape our society and our planet.

Journal Club is meet up of Grantham Scholars to discuss publications from a multidisciplinary perspective. It is part of the Grantham Scholar training programme.

Edited by Claire Moran. Photo by Vanessa Loring from Pexels.