Genevieve S Metson et al 2012 Environ. Res. Lett. 7 044043
http://iopscience.iop.org/1748-9326/7/4/044043

In this article we explore the relationship between human diet and phosphorus (which I will refer to as P).

P is an essential element to all life, it's in our bones, and it comes from the plants and animals we eat. Because it's an essential nutrient, it is a fertilizer we use in agricultural production to ensure high yields.

The P we use a fertilizer mostly comes from mines, and thus it is a non-renewable resource. In addition P is concentrated in deposits unevenly across the globe.

Once P is applied to fields some goes into crops, and then into animals, but a lot of P is lost along the way. And this lost P can then cause eutrophication downstream

Here we look at how changes in national diets across the world from 1961 to 2007 affect requirements of mined P. We did so by calculating the P footprint, which is the average amount of mined P required to produce the food consumed per capita per annum Ð based on diet composition for every country in every year.

Total global P requirements to produce food went up between 1961 and 2007, in part because of population increase, which is represented here by the dotted line where we multiplied global population by the 1961 average P footprint thus a constant diet scenario. Now if we consider diet changes and population growth together, the black line here, we can see that P requirements are even higher. Shifts in diet accounted for almost 28% of the increase in demand for mined P since 1961. The global P footprint went from 1.9 to 2.6 kg P capita.

Still, P footprints vary around the globe. In 1961 we can see this variability where North America, Oceania, most of Europe and parts of South America are very high in red. Asia and Africa are mostly low in yellow. Changes through time were also different. China increased its P footprint 400%, most counties with high P footprints remained high. In 2007, P footprints varied between 0.35 kg P capita-1 year-1 (DPR Congo) and 7.64 kg P capita-1 year-1 (Luxembourg).

Here we see the average P footprint of a person in a selection of countries and the proportion of the P footprint made up of meat, egg, and dairy in black, and vegetables, fruits, and grains in white.

Not all dietary choices have equal impact on P footprint values. Meat, egg, and dairy consumption account for the majority of an individual's P footprint and thus countries with high meat consumption have a higher P footprint. 

About 72% of the global average dietary P footprint between 1961 and 2007 was due to consumption of animal-based food groups. Beef is the most P intensive meat.

High P footprints are correlated to wealth and development. Here we see how Human Development Index (HDI) and 2007 P footprint values, represented as the log of P footprint here, have a positive linear relationship.
      
Our results show that dietary shifts are an important component of the human amplification of the global P cycle. This may mean that future meat consumption could play an important role in the demand for P resources. Decreasing meat consumption in already high P footprint countries could play an important role in sustainable P management strategies, in addition to increasing the efficiency and recycling of P throughout the food chain.