TUCKING into a delicious burger may be one of life's luxuries, however, now we should be watching what we eat not just for the sake of our waists but also for the sake of the planet, according to scientists.
Experts have calculated that if everyone in Scotland sheds half a stone, it could save the equivalent amount of greenhouse gas emissions as taking 1.2 million cars off the roads each year.
The study, by scientists at the London School of Hygiene a
nd Tropical Medicine's department of epidemiology and population health, highlights that food production is a major contributor to global warming.
Fertiliser produces nitrous oxides, methane come from cattle and carbon dioxide emissions are produced by agricultural transport.
The researchers claim that a lean population – such as that in Vietnam – will consume almost 20 per cent less food than a population in which 40 per cent of people are obese, similar to the level seen in the United States.
Transport-related emissions will also be lower if people are slim because it takes less energy to move them around.
Dr Phil Edwards, one of the leaders of the study, said that the average weight of a person in the UK has increased by about half a stone in the past 30 years.
In Scotland this will have added about five million tonnes of carbon dioxide emissions – the equivalent of adding about 1.2 million cars to the roads.
Dr Edwards said he thought people had a "responsibility to the climate".
"It's about seeing that actually as a population by being a particular shape and by being a certain weight we have an impact on the climate," he said.
"It's something that isn't discussed widely, but not only is staying slim good for you but it's also good for the planet."
He added: "I think the government needs to recognise that population fatness has an environmental effect. That's what is missing from the whole debate."
In the research paper, the authors highlighted that, worldwide, people are becoming fatter, whether in Australia, Argentina, Belgium or Canada.
And Dr Edwards said the situation would be likely to become even worse because in developing countries, where populations are often underweight, many people are also beginning to eat more.
He added: "'When it comes to food consumption, moving about in a heavy body is like driving around in a gas guzzler.
"The heavier our bodies become the harder and more unpleasant it is to move about in them and the more dependent we become on our cars."
The Scottish Government has a target of cutting greenhouse gas emissions by 80 per cent by 2050.
Duncan McLaren, the chief executive of Friends of the Earth Scotland, highlighted that people with eating disorders should not be encouraged to lose weight.
He added: "Their point is an absolutely valid one, that a healthy diet can be good for health as well as good for the planet. The idea of a low-carbon diet involves a low-meat diet."
Mr McLaren, who said his own diet was "largely vegetarian" pointed out that losing weight went hand in hand with cycling and walking, which are also good for the environment.
The study appears today in the International Journal of Epidemiology.
SCOTLAND'S BIG ON ILL-HEALTHSCOTLAND has among the highest obesity levels in the world.
Research last year showed Shetland, Orkney and the Western Isles had the highest proportion of patients with a body mass index (BMI) of 30 or above – meaning they would be diagnosed as obese.
Obesity places people at risk of serious health consequences, such as diabetes, heart disease and shortened life expectancy.
A BMI of under 20 is underweight, 20-25 is normal and 25-30 is overweight.
The research showed Lothian had the fewest number of obese people, followed by Fife, the Forth Valley, Argyll and Clyde, Ayrshire and Arran, Borders, Greater Glasgow and Highland.
