Three scant years ago, Shanghai celebrated the 100th birthday of one of history's most famous junk foods — the Oreo biscuit — with fireworks on the Bund and multi-storey neon adverts projected on to skyscrapers. But now China has put Oreo on a diet.
But in the past few years, China has begun to discover that heavy metals are not the only things to avoid in snack foods. There is that small matter of fat and sugar, too. Last week, Chinese media carried stories saying that Mondelez, the maker of Oreo, was shutting down some Shanghai production because people were going right off biscuits.
That's not Oreo's only problem: many of the world's most successful brands made it to China early and had a long run almost unrivalled, but are losing their first-mover advantage. (KFC has that problem too, compounded by a spot of bad publicity on the food quality front.)
Meanwhile, mainlanders have developed one of the most fickle palates on earth: Americans may want the same cookie Mum gave them with their milk after school; but Chinese want something new every day. Local companies are often nimbler than multinationals at introducing green tea or purple sweet potato alternatives to traditional flavours.
And cookie companies are facing competition from an even more unlikely source: home bakers. When I moved here, ovens were rare in normal homes: I figured that was why mine didn't work too well. But now many a Chinese bride insists on having one. Sales of the countertop ovens preferred on the mainland have more than quadrupled since I started wielding a flour sifter on Chinese shores, and a 318-piece everything-you-could-ever-need baking set can be had on Alibaba's Taobao for only 137 devalued renminbi.
For, given that the vast majority of Chinese under 30 have never known an hour of hunger in their lives, let alone survived on roots and shoots, just filling the tummy is no longer the point.
They cook for fun — and for health reasons, says Qian Zhaoli, a 27-year-old marketing manager in Shanghai. She's started baking her own rusks because her first child is teething. "I wanted her to have the healthiest ones, without any additives," she says, adding that shop-bought rusks have such a long shelf life, and "who knows how many artificial colours and preservatives they contain?"
Plus, western-style baking is far easier than cooking any of China's complicated cuisines, she says, noting that in Shanghai most cooking is done by men.
This is not just a tale of Oreos and ovens. It is a parable for a new type of Chinese consumption: more finicky, more fickle — potentially less profitable. Anyone selling almost anything here should watch it closely.