Australians and New Zealanders munched the most chocolate in the world in 2013, eating 4.8kg per person, slightly more than by Western Europe (4.6kg), according to a report from business news service Bloomberg.

But there could be problems ahead for Kiwi chocolate lovers, with the world facing its longest cocoa supply deficit streak in 50 years, the report says. Worldwide cocoa demand will outpace production again in the next season that started in October, and high prices are set to continue.

The Bloomberg survey of five analysts and traders predicts the supply deficit is expected to be 1 million tonnes by 2020, which equates to about one-quarter of global output if growers maintained the current rate of production. Last year, the world ate roughly 70,000t more cocoa than it produced. By 2030, the deficit could reach 2m tonnes.

Supply has been shrinking due to poor weather, poor yields, disease, and farmers shifting to better value crops, according to the Washington Post.

But demand from Asia has been increasing – and looks set to continue to rise. At the moment, Asia Pacific consumers eat an average of about 200g per person, with the average Chinese consumer eating only a little more than two candy bars’ worth of chocolate a year.

However, as Asians, in particular China’s 3.7 billion people, get the bug, the chocolate confectionery market in the Asia-Pacific region is forecast expanding 23% to US$16.3 billion by 2018, according to research company Euromonitor. The world market, dominated by Western Europe and North America, will grow 13% to about US$124b over the same period, it says. 

Already, cocoa prices have climbed by more than 60% since 2012, when people started eating more chocolate than the world could produce.

Dry weather in West Africa (specifically in the Ivory Coast and Ghana, where more than 70% of the world’s cocoa is produced) has seen production slump in the region.

Meanwhile, a nasty fungal disease known as frosty pod also contributed to the problem. The International Cocoa Organisation estimates the disease has wiped out between 30% and 40% of global coca production. Because of these factors, cocoa farming has proven to be a particularly tough business, and many farmers have shifted to more profitable crops, like corn, or rubber.

The Ivory Coast and its neighbour Ghana only harvest an average of 400 kg of beans per hectare while a farm that’s well-managed with fertilizers and pesticides can yield up to 1.5 tonnes per hectare, Bloomberg says, citing Damien Thouvenel, a cocoa trader for Sucres et Denrees SA, in Paris. 

Cocoa farmers are among the poorest paid in the world. According to makechocolatefair.org, cocoa growers receive about 6% of the price consumers in rich countries pay for their chocolate.

Cocoa futures prices hit three-year highs in September on fears Ebola’s spread may disrupt supplies from West Africa.

At New York’s Intercontinental Exchange where commodities futures are traded, cocoa for delivery in December was traded as high as US$3,259/t after touching $3,273, the highest since August 29. It has fallen somewhat following news from the International Cocoa Organisation that farmers worldwide would harvest 10% more cocoa beans this season (ended September) than they did a year ago.

Global chocolate confectionery makers M&M, and Snickers-maker Mars, have raised prices by about 7% for US chocolate products to offset rising costs. Hershey has also raised its prices 8% due to higher costs for cocoa, milk and other commodities.