Ever wondered just where humans fall on the food chain? Wonder no more. Researchers have calculated our precise location (somewhere right next a pig or an anchovy, apparently), along with another surprising trend: While we're firmly omnivores, we're also becoming more and more carnivorous.
Top image: mayhem.
In a study published in PNAS, researchers took a look at the country-by-country data from the UN's Food and Agriculture Organization on all the different kinds of foods eaten to calculate our collective trophic level — the 1-5 measure of just where various plants and animals fall on the food chain. Smithsonian's Surprising Science blog explains: "On a scale of 1 to 5, with 1 being the score of a primary producer (a plant) and 5 being a pure apex predator (a animal that only eats meat and has few or no predators of its own, like a tiger, crocodile or boa constrictor), they found that based on diet, humans score a 2.21—roughly equal to an anchovy or pig."
While occupying the same space as an anchovy may be a slightly humbling experience, it turns out that the number isn't at all static. In the last 50 years, humanity's trophic level has bumped up from 2.15 to 2.21, which is actually a pretty sizable jump, according to Nature:
"It seems like a small difference, but when you think about how it's calculated, it's big," says Thomas Kastner, an environmental scientist at Alpen-Adria University in Vienna, who was not involved in the study. An organism's trophic level is calculated by summing the trophic levels of the foods in its diet and the proportion in which they are consumed. "A change by 0.1 means you are eating considerably more meat or animal-based foods," says Kastner."
Of course, while our global level of meat consumption is on its way up, that doesn't tell the whole story. Checking out this graph of the trophic levels of individual countries, the wide range of diets is pretty clear.
Image: A map of human trophic level variations by country, PNAS (via Nature).
And, as Surprising Science notes, whether (and by how much) meat consumption has increased or decreased in a country varies wildly:
A group of 30 developing nations in Southeast Asia and Sub-Saharan Africa —including Indonesia, Bangladesh and Nigeria, for example—have had HTLs below 2.1 during the entire period. But a second group of developing countries that includes India and China has slightly higher HTL measures that have consistently risen over time, going from around 2.18 to over 2.2. The HTLs of a third group (including Brazil, Chile, South Africa and several countries in Southern Europe) have risen further, from around 2.28 to 2.33. By contrast, HTL in the world's wealthiest countries —including those in North America, Northern Europe and Australia—was extremely high for most of the study period but decreased slightly starting during the 1990s, going from around 2.42 to 2.4. A fifth group of small, mostly island countries with limited access to agricultural products (including Iceland and Mauritania) has seen more dramatic declines, from over 2.6 to less than 2.5.
So what do you think? Will the global trend towards eating more meat continue with time or taper off? Does this study fit in with your own eating patterns? And what other kinds of trends do you predict for global food consumption? Tell us your thoughts now in the comments.