The excess intake of calories is another major global public-health concern, as overweight and obesity cause more than 2.8 million deaths per year among adults. On the demand side, population growth, rapid urbanization and consequent changes in consumption patterns will require additional food. The Food and Agriculture Organization of the United Nations (FAO) estimates that food production will have to increase 70 per cent globally to feed an additional 2.3 billion people by 2050. At the same time, food demand has been shifting towards more resource-intensive agricultural products, such as livestock and dairy products, thereby exerting additional pressure on land, water and biodiversity resources. Many of the current agricultural practices have relied on cheap energy and abundant water and land, and are a leading source of greenhouse gas emissions (The Hague Conference, 2010). These practices are now proving unsustainable for the environment and health, due to contamination of air, land and water sources.