It’s more than calories: finding convergence between nutrition, food systems and environmental sustainability

Food, for me, lies at the core of the environmental-social-economic nexus: a basic human necessity which both relies on, and contributes to natural resource pressures. Agriculture is the largest consumer of global freshwater supplies (accounting for 70-80% of consumption); accounts for half of global habitable land (as shown in the graphic below); and is responsible for roughly one-quarter of global greenhouse gas (GHG) emissions. The growing scarcity of these natural resources, combined with impacts of climatic change, population growth and economic growth (which drive a change in dietary patterns) combine to create the so-called ‘perfect storm’ of the future.


Coming from an environmental background (my BSc was in Environmental Geoscience, and my MSc in Carbon Management at Edinburgh), my primary concern was initially focused on the ecological impact of global agriculture—on how to reduce and mitigate the impact of the food system on environmental degradation. This goal, however, completely excludes a human dimension or motivation for change, neglecting to acknowledge the key purpose of food—to provide nourishment.

This nutritional challenge is also one we are failing to meet at the global level: 815 million (one-in-nine) people were undernourished in 2016; an estimated one billion people suffer from protein deficiency; one-third of under-5s are born stunted (low height-for-age); more than two billion suffer from micronutrient deficiencies (also known as ‘hidden hunger’); and paradoxically two billion adults are classified as overweight or obese, with strong links to an alarming rise in the prevalence of non-communicable diseases (NCDs) such as type-II diabetes and heart disease. This challenge exists across countries of all income levels, high-income nations included.

prevalence-of-undernourishment (1)


If our aim is to fulfil the basic, classic definition of sustainability, to “meet the demands of the current generation without sacrificing the opportunities of future generations”, we need to achieve both of these dimensions—meeting the nutritional demands of everyone in the current generation whilst also reducing environmental impacts for future generations. Focusing on only one of these dimensions is insufficient: if you fail in either, you fail in sustainability. The emphasis of my PhD work has therefore evolved to find the sweet spot where both health and environment converge.

The standard metric for tracking progress on global nutrition and related health outcomes—caloric intake—is now outdated. As the fundamental measure used to track progress on ending ‘hunger’ within the previous Millennium Development Goals (MDGs), it’s not surprising that most countries have tracked nutritional progress based on their ability to produce enough calories for their population. The updated Sustainable Development Goals (SDGs), which have a target date of 2030 broaden this goal to ending all forms of nutrition. This effectively extends the targets and measures we need to include protein, fat, micronutrients, amino acids, obesity and diet-related non-communicable diseases (NDCs). Many high-income countries also struggle with many of these nutritional challenges—the SDGs are therefore a truly global health challenge.

How do we develop a global food system which nourishes (not just feeds) everyone in an environmentally sustainable way? The first step—and one I’m trying to address in my research—is understanding what the food system currently looks like across these various nutritional elements. We understand how many calories we produce, how much we feed to animals, where it flows through the supply chain, and how much is lost/wasted fairly well. However, our understanding of these pathways for other nutrients essential for health is comparatively poor.

The next step is to estimate how this demand and supply will change in the future through various socioeconomic and environmental drivers—this is an area we know even less about. Once we have developed a picture of what our current system and future demands look like, we can begin to analyse what levers or hotspots within the food system we can target to make it more environmentally sustainable, achieving the right balance in nutritional components necessary for human health.


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