If the developing world adopts a typical American diet, the consequences for health and the environment could be tragic. According to a major new study, we’d see a big rise in type 2 diabetes and heart disease, and massive growth in carbon emissions. What emerging countries choose to eat in the years ahead couldn’t be more important.
“Because it directly links and negatively affects human and environmental health, the global dietary transition is one of the great challenges facing humanity,” explains the paper, which published in the latest edition of the journal Nature.
As people become richer, three changes tend to happen. First, they eat more meat protein. The richest 15 countries consume 750% more beef, lamb, seafood, poultry, and pork than the 24 poorest nations. Second, they take on more “empty calories” in the form of refined fats and sugars, alcohols and oils. And third, they tend to take more calories than needed. The study estimates that on average a person making more than $12,000 a year eats 500 more calories than strictly necessary.
That’s caused 2.1 billion people to become overweight or obese, and led global agriculture to produce 25% of all greenhouse gas emissions. By 2050, the paper says those emissions could rise another 80%, if trends continue as today. That includes emissions from farming itself as well as deforestation.
The study is authored by David Tilman, a professor at the University of Minnesota, and Michael Clark, a graduate student at the University of California Santa Barbara. They compiled hundreds of previous studies looking at food-related impacts on health and the environment.
Their conclusions aren’t completely bleak. The way that food is produced makes a big difference. For example, seafood caught with a trawler has three times the climate impact as seafood caught traditionally. And relatively small changes in diet can go a long way. Mediterranean, pescetarian and vegetarian diets reduce type 2 diabetes by between 16% and 41% and cancer by 7% to 13%. Meanwhile, 20 servings of vegetables have fewer greenhouse gas emissions than one beef serving.
Says the study:
“Our analyses demonstrate that there are plausible solutions to the diet–environment–health trilemma, diets already chosen by many people that, if widely adopted, would offer global environmental and public health benefits.”