By Hannah Hoag, Nature

The fast-growing economies of China and India are driving a global increase in meat consumption, canceling out decreases elsewhere, according to a comprehensive study of global food consumption.

The work, published this month in Proceedings of the National Academy of Sciences, takes a detailed look at what people eat, as well as trends from one country to the next. It is also the first time that researchers have calculated humanity’s trophic level, a metric used in ecology to position species in the food chain.

The metric puts plants and algae, which make their own food, at trophic level 1. Rabbits, which eat plants, occupy level 2. Foxes, which eat herbivores, sit at trophic level 3. Cod, a fish that eats other fish, claims level 4. Polar bears and orcas, which have few or no predators and eat other mammals with gusto, hold the top positions — levels up to 5.5.

The study, led by Sylvain Bonhommeau, a fisheries scientist at the French Research Institute for Exploitation of the Sea in Sète, estimates that humanity’s global median trophic level was 2.21 in 2009, which puts us on a par with other omnivores, such as pigs and anchovies, in the global food web. “We are closer to herbivore than carnivore,” says Bonhommeau. “It changes the preconception of being top predator.”

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