Sales of custard creams and the humble digestive biscuit are crumbling as Britons opt for healthier and more indulgent treats.
Sales of "everyday biscuits", a segment that also includes Rich Tea, have sunk by almost one million packets a week.
Researchers Kantar Worldpanel say sales of cereal bars and Jaffa Cakes are up, as are chocolate-coated biscuits.
"It's part of the changing nature of snacking," says Kantar's Retail Insight chief, Fraser McKevitt.
The UK biscuit business is worth £2.4bn - down about 0.3% on last year. "It's not a story about a decline in the purchasing of biscuits - it's the changing tastes," he says.
Sales in the "everyday" category fell 7.1% and are now worth about £300m.
The "Children's biscuits" category, which includes Jammie Dodgers, fell 2.8% to £110m.
One of the big biscuit winners over the past 12 months has been the premium "special treats" category, where brands Bahlsen and Fudges have done well, Mr McKevitt says.
"There are more people saying to themselves: 'If I'm going to eat fewer biscuits, then when I do I'm going to treat myself'," he says.
The biggest sub-sector in the biscuit market is the "healthier" category. This continues to grow, up 1.3% to £517m in the last year.
Cereal bars and most biscuits made with oats did better. BelVita bars saw a £5.6m rise in sales.
"We saw a similar change in tastes with fizzy drinks," says Mr McKevitt. "Biscuits are inherently a sugary product. Brands across all categories are changing recipes to take out sugar, salt and fat."
One growth market to watch for is the so-called "nibbles range": one-bite wonders sold in assortment packs.
"It's not just biscuit tastes that are changing," Mr McKevitt explains. "The shape and size are changing too."