A slim population is a more sustainable one.

A report "Population adiposity and climate change" by Phil Edwards and Ian Roberts links low levels of obesity to reduced greenhouse gas emissions. As reported by Sophie Blakemore over at Worldchanging;

"Countries with normal rates of obesity (3.5%) consume almost 20% less food and produce up to one gigatonne fewer greenhouse gases than a population with a 40% obesity rate....

One European city has already risen to the challenge. Ghent council, in Belgium, has declared every Thursday vegetarian day, to encourage its inhabitants to eat less meat and so take a step to more sustainable living.

To date, 94 restaurants have agreed to guarantee at least one vegetarian dish on Thursdays, the council claims, with some going completely meat-free. From September the main dish at all primary schools on that day will be vegetarian. Other cities, including São Paolo in Brazil and Genoa in Italy, have expressed an interest in replicating the move.

In the UK, former Beatle Sir Paul McCartney and his daughters Stella and Mary have launched a ‘Meat Free Monday’ campaign, to raise awareness of vegetarianism and highlight the impact of food choices on the environment.

Researchers at the Institute for Environmental Studies in Amsterdam have come up with figures claiming that if every UK citizen took up the idea, the associated reduction in carbon emissions would be equal to taking five million cars off the road."