Humans, like all other creatures great and small, exist in the global food web. But it’s not where you think. We’re not on top.
When researchers from a number of French marine and agricultural science institutes calculated countries’ trophic levels–essentially, measures of energy that inhabitants consume through eating–they found that consumption habits over the last 50 years varied wildly. Their data, published in the Proceedings of the National Academy of Sciences, also documented a world growing increasingly hungry for meat.
To break it down: Trophic levels cover the spectrum of eating habits, from herbivore to the most carnivorous predators. A trophic level of 1 means you’re a plant or plankton, and level 2 means you eat level 1. A level 2.5 might signify a mixed diet of plant and plant-eaters (like a chicken caesar salad), and a trophic level of 5.5 (the highest) likely means you’re a polar bear. Humans fall somewhere in the 2 to 2.6 range, which means we actually occupy the same space in the food web as pigs and anchovies.
It was probably time to ditch that whole “top predator” nonsense anyway. But the story of human trophic levels isn’t just about meat. These maps show the history of energy consumption through our mouths over the last 49 years. As the authors of the paper stress, a higher trophic level means we’re depleting more of our natural resources, and subsisting on food that requires the most food-chain energy to make. McRibs don’t grow on trees, after all.
In sum, the global median trophic level has grown 3% over the last half-century, with much of that growth coming from India and China. While populations in North America, northern and eastern Europe, Australia, and New Zealand led in meat and fat consumption at the 1961 outset, in more recent years those trophic levels have declined.
Scandinavian countries, Mauritania, and Mongolia have some of the highest trophic levels in the world, but the Swedish government recently imposed a series of taxes on meat to encourage healthier eating. Increased development in the latter countries also shows a trend moving away from nomadic hunting to urban living.
In the United States, diets made up mostly of land animals have decreased, likely due to new awareness of cardiovascular health risks from consuming too much red meat. But as the maps show, it doesn’t look like we’re fully embracing our broccoli, either.