We all know we should aim to eat a healthy diet for ourselves, but have you considered the impacts of an unhealthy diet on the environment? Diets high in added sugars and saturated fats, are having a serious effect on the planet as well as human health.

The Lancet Commission on healthy diets from sustainable systems outlines a way we can go about improving the world’s diets whilst bringing us closer to the targets set out by the 2015 Paris Agreement [1]. They set out a recommended healthy diet (see figure.1) and ways our food systems can change to hit our climate goals.

A move to what the commission call ‘win-win’ diets will need a major transformation in the way food is managed. Agriculture will need to produce a larger diversity of crops whilst keeping to the same amount of land, and governments will need to implement stricter policies to enforce this[1]. Land could be freed by reducing our consumption of red meat; reducing the area needed for grazing and growing feed. In turn, a reduction of red meat in our diets reduces the likelihood of obesity and heart disease which are both prevalent worldwide[2].

Figure 1: The Lancet Commission’s recommended daily intake of different food groups. Modified from data from source 1

As well as land, nutrients used in fertiliser like nitrogen and phosphorus will also need to be conserved and recycled. Their reserves are limited so they need to be used and distributed in the most effective manner to gain the greatest crop yields[1]. Furthermore, if they get into waterways, they can cause serious damage to aquatic ecosystems through eutrophication (the formation of algae blooms that block sunlight damaging water quality)[3] and so their management is vital for our diets to be sustainable.

The same can be said for water usage as water intensive crops should be grown in regions where it is readily available. These crops then need to be accessible to more arid countries to trade, ensuring everyone maintains healthy diets[1]. Therefore, international cooperation is needed as water insecure countries often struggle to develop a strong national economy[4].

So, if it’s going to take this much to improve, why do it? Unfortunately, we may not have much of a choice if we want to make sure no one goes hungry. The population is expected to increase to 10 billion by 2050[5] and so more food will need to be produced on the same amount of land as today, so as not to further degrade our environment. Therefore, the yield of our crops needs to increase to reduce the amount of food loss, and the amount of food wasted in all areas needs to decrease.

Today ‘820 million people have insufficient food’ with many more having underlying micronutrient deficiencies. Replacing a portion of starchy carbohydrates with protein rich foods could greatly increase the nutritional content of many peoples’ diet[1]. Just a small change could have a major impact on life expectancy as well as the world’s progress towards climate and environment targets.

—

References

1. Willett, W., Rockström, J., Loken, B., Springman, M., Lang, T., Vermeulen, S., Garnett, T., Tilman, D., DeClerk, F., Wood, A., Jonell, M., Clark, M., Gordon, L. J., Fanzo, J., Hawkes, C., Zurayk, R., Rivera, J. A., De Vries, W., Sibanda, L. M., Afshin, A., Chaudhary, A., Herrero, M., Agustina, R., Branca, F., Lartey, A., Fan, S., Crona, B., Fox, E., Bignet, V., Troell, M., Lindahl, T., Singh, S., Cornell, S. E., Reddy, K. S., Narain, S., Nishtar, S., Murray, C. J. L. (2019) Food in the Anthropocene: the EAT-Lancet Commission on healthy diets from sustainable food systems. The Lancet 393, 447-492
2. Wang, Y., Beydoun, MA. (2009) Meat consumption is associated with obesity and central obesity among US adults. International Journal of Obesity 33, 621-628
3. Chislock, M. F., Doster, E., Zitomer, R. A. & Wilson, A. E. (2013) Eutrophication: Causes, Consequences, and Controls in Aquatic Ecosystems. ‘https://www.nature.com/scitable/knowledge/library/eutrophication-causes-consequences-and-controls-in-aquatic-102364466/’[30.11.20]
4. United Nations (nd.) Water. ‘https://www.un.org/en/sections/issues-depth/water/’[02.12.20]
5. United Nations Department of Economic and Social Affairs (2017) World population projected to reach 9.8 billion in 2050, and 11.2 billion in 2100. ‘https://www.un.org/development/desa/en/news/population/world-population-prospects-2017.html#:~:text=News-,World%20population%20projected%20to%20reach%209.8%20billion%20in,and%2011.2%20billion%20in%202100&text=The%20current%20world%20population%20of,Nations%20report%20being%20launched%20today.’[25.11.20]