Easy to make and cheap to buy, instant noodles have long been China's ultimate convenience food.


Be it a snack for students, a meal on the train, or just the go-to choice for hungry workers, more than 46.2 billion packets were sold in China in 2013.


But by 2016 those sales had tumbled to 38.5 billion packets, according to the World Instant Noodle Association. That's a drop of almost 17%.


Given most other instant noodle markets have remained fairly steady over the past few years - it is an unusual pattern.


So what's going on? Well here are some theories - which suggest instant noodles could be, in many ways, a great indicator of how China is changing.


Aspiration: Customers want better food


The recipe for instant noodles is fairly straight forward: Just add boiling water, a sachet of sauce, and some small packets of dehydrated vegetables and meat.


As appetising as that sounds, one factor in the slump could well be that some Chinese consumers are upping their expectations in the dining department.


The decline of instant noodle sales shows a shift in China's consumption patterns. Consumers are more interested in life quality than just filling their bellies these days.


Population shift: Rural workers are going home


One of the big consumers of instant noodles - the theory goes - are migrant workers. They are away from home, often living in cramped conditions with limited cooking facilities, and keen to save as much money as they can to send back to their families.


Until 2014 the number of rural Chinese who had moved to cities had been on the rise.


But that trend has now reversed for two consecutive years.


Travel: Infrastructure improving, habits changing


Travelling in China 20 years ago, I filled my stomach (and time) by eating pot after pot of instant noodles during cross-country train journeys, which sometimes lasted three days or more.


But Chinese trains and stations have improved. Journeys are quicker, and the range of food options are far more international - meaning noodle sales on the railways have fallen.


And then there is the boom in aviation as middle class Chinese people spend billions flying on holidays instead of using trains.


Smartphones and the internet: There's another form of 'quick food'


About 730 million people in China now have access to the internet. And about 95% of those are using smartphones to connect.


And apps that offer food delivery to your home, office or wherever you happen to be are a real boom industry.


Their menus are undoubtedly more expensive than a pot of instant noodles. But these meals can still be inexpensive. And arguably more tasty.




But put in the global context China is still the biggest market for instant noodles as this chart shows:


Almost three times as many packets were sold in 2016 than in Indonesia.


In fact China's total was roughly the equivalent of Indonesia, Japan, Vietnam, India, the US, South Korea and the Philippines combined.


And that means global noodle manufacturers are unlikely to turn away from the Chinese market.


"Some consumers stopped consuming instant noodles, but most consumers want to increase the quality (of food they consume)," chief executive Kiyotaka Ando, Japan's instant noodle business Nissin Foods, said.


"We can supply high-quality products so we have more possibility to develop our business."