May'19 Board Book

The most contentious part of the diet involves livestock, which emit 14.5 percent of the globe’s greenhouse gases , and specifically cows, who release more of those gases than any other farm animal. The study’s authors contend that meat consumption is expected to continue rising, and if that happens, the amount of heat-trapping methane to enter the atmosphere would be devastating. But its detractors, including University of California-Davis air quality scientist Frank Mitloehner, say that methane from cows isn’t a big problem in the first place. In fact, critics argue, the legume-and-grain-heavy diet prescribed by the EAT-Lancet Commission would necessitate deforestation for row crops, which would create problems of its own. (Mitloehner is advising Rep. Alexandria Ocasio-Cortez’s policy team on Green New Deal legislation. ) In his complaint, Cornado, the Italian ambassador, said that African countries like Ethiopia depend on livestock, and that if the recommendations were implemented, it would ruin their economy. A fair point, but throughout their report , the authors point out that the diet should vary from place to place, specifically because of those issues. He also takes issue with the nutritional claims. The study’s authors say that the diet—which calls for major increases in consumption of whole grains, legumes, fruits and vegetables, and conversely, decreases in anything that comes from animals—would go a long way in reducing weight-related disease and mortality. But it would also result in low intakes of iron, retinol, and vitamins B12 and D3, according to at least one dietitian’s analysis . (Walter Willett and Johan Rockström, who co-chaired the report, have called their report “the most up-to- date scientific evidence for healthy diets,” Meatingplace reports (registration required). It’s not the ecological claims, though, that led WHO to back off.

This wasn’t the first time that EAT has struggled with its diet’s rollout.

Cornado may be right to be skeptical of that science. The planetary health diet is based on a synthesis of preexisting nutritional science, including research undertaken by Willett, a Harvard professor who’s a big believer in the Mediterranean diet. But nutritional science’s history is up for perpetual debate, for the simple reason that the findings are very rarely reproduced in randomized trials, says John Ioannidis, a professor of medicine, health research, and policy at Stanford University.