Emma Duncan found the ageing snack at the bottom of an old box of crockery taken to her bric-a-brac shop.
The distinctive red packaging is clearly stamped with a best before date of Oct. 1, 1995 and the wafer’s foil wrapping was perfectly intact.
She then bought a new KitKat to compare the two versions only to find the old wafer bar was 6.5g heavier than the new one.
Emma also noticed that the biggest ingredient in the old bar was milk chocolate — whereas the main ingredient in today’s bar is listed as sugar.
The mum-of-one, who runs shabby chic store The Den in Warsop, Nottinghamshire, said: “We get some really lovely things in the shop but everyone has gone crazy over an old KitKat.”
But chocoholic Emma has managed to resist tucking in to the treat since she discovered it last week.
She added: “I’m sure I’d have a tummy ache after eating that. I’ll have to make sure my eight-year-old boy, Caiden, doesn’t get his hands on it.
“I’m now being known as the KitKat lady, which makes me smile.”
KitKat is a chocolate-covered wafer bar confection created by Rowntree’s of York, United Kingdom in 1935 and now owned by Nestle.
The original four-finger bar was created after a Rowntree’s worker put a suggestion in a recommendation box for a snack that “a man could take to work in his pack”.
The bar launched on 29 August 1935, under the title of Rowntree’s Chocolate Crisp, and was sold in London and throughout Southern England.
The traditional bar has four fingers which each measure approximately 1cm by 9cm.
A two-finger bar was launched in the 1930s and has remained Nestle’s best-selling biscuit brand ever since.
However, the recipe was changed in April of this year for the first time in more than 30 years.
The new four finger bars, which can be distinguished by the label ‘now with extra milk & cocoa’, have 21.3g of sugar — versus the old bar’s 22g of sugar.
But compared to the 1995 chocolate treat there is more sugar within the carbohydrates of the bar — with it gaining 3.3g extra of the compound over the past two decades.
The new bar is also around 10 per cent smaller — meaning today’s bar contains more sugar than its 22-year-old predecessor.
Nutritionist Laura Tasker, 22, said: “There has been a big decrease in the size of the bar while the amount of carbohydrates has increased.
“The big decrease in the size of the bar contrasts with only a small reduction of fat and an increase in carbohydrates.
“Those carbohydrates are mainly sugar whereas the size has decreased by almost 10g.
“This shows that the 1995 bar was actually healthier than today’s equivalent.”
This article originally appeared on The Sun and has been republished with permission.