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Western diet's spread bad for health, climate? It doesn't have to happen

Three diets could save the world

Over the next 35 years or so, the populations of the world's wealthiest nations are expected to be joined at the banquet table by the growing populations of countries undergoing rapid development.

If past patterns dictate the menu, the serving staff will have to call out to the world's farms and fisheries for lots more meat, poultry and fish, and a whole lot more sugar. They'll be scaling back their orders for the fruits, vegetables and legumes that have been a mainstay of poorer countries' diets for eons.

Putting all this food on the table, says a study published Wednesday in the journal Nature, will drive an escalation of forests cleared for increased meat production. Feeding the growing guest list will also increase fuel expenditures to operate tractors, seagoing trawlers, refrigerators, fertilizer production, transportation and industrial food processing plants.

The result -- if nothing changes -- would be a sicker planet all around, the new research calculates. As the developing world's diet shifts to more unhealthy fats, higher consumption of sugar and more processed food, not only would global rates of Type 2 diabetes, certain cancers and heart disease rise. So too would the amount of greenhouse gases spewed into Earth's atmosphere.

A new global analysis by University of Minnesota ecologists David Tilman and Michael Clark predicts that by 2050, growing affluence and growing demand for a Western-style diet would increase the volume of greenhouse gases to 4.1 gigatons from 2.27. By the middle of this century, they reckoned the dietary demands of a more affluent world would drive an 80% increase in yearly greenhouse gas emissions related to food production.

But neither poor health nor runaway greenhouse gas emissions are written in stone, the authors said. Compared with traditional Western-style diets rich in red meat, processed foods and sugars, three diets -- vegetarian, Mediterranean and pescatarian -- drive lower rates of fossil fuel consumption and could be expected to yield better health.

A vegetarian diet has been found to greatly reduce the risk of Type 2 diabetes, cancer and coronary mortality. A Mediterranean diet, which is rich in fruits, vegetables, nuts and legumes and eschews most red meat for leaner chicken, fish and healthy fats, has been shown to dramatically drive down coronary mortality and, to a lesser extent, Type 2 diabetes and cancer. A pescatarian diet -- a vegetarian diet that includes seafood -- has been found to reduce risk of all three and is particularly potent in lowering cancer risk.

If the world's banquet table in 2050 were shared by adherents to vegetarian, Mediterranean and pescatarian diets in equal measure, Tilman and Clark estimate that greenhouse gas emissions from food production would remain stable, despite diners' greater affluence. Food production's contribution to greenhouse gases could be driven down further by more efficient use of cropland, fertilizer and irrigation and by measures that reduce food waste, they said.

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