Manufacturers have shrunk 2,529 products over the past five years while keeping prices the same, official data shows.
Shoppers with a sweet tooth have been the worst affected by the trend as chocolate, confectionery, jams and syrups have seen the most items downsized, according to analysis by the Office for National Statistics.
Since 2012, the inflation rate in this category was actually 1.22 per cent higher than the official recorded level, when the smaller size was taken into account.
While weight changes have happened most frequently in food products, non-food items are also being sold in smaller packet sizes, the ONS found. However, these size reductions have not added significantly to inflation, it concluded.
"Shrinkflation" has therefore not made any significant impact to overall inflation, because confectionery makes up just 0.01 per cent of the basket of goods the ONS uses to calculate price rises in the economy.
The data also showed that 614 products got larger between 2012 and 2017, but the contracting products have garnered much greater attention over the last year.
Maltesers sharing packs now weigh 93g, down from 103g, compared with 121g in last autumn. Mars, which makes the chocolates, said in March that it had taken the decision in order to help people afford the product as the company combats rising commodity prices.
M&M’s family packs have shrunk by 25g to 140g and bags of Minstrels and Revels are almost 10 per cent lighter.
Toblerone sparked controversy last year when it cut the size of its iconic bar by 12 per cent, with larger spaces between the triangular “mountains”.
The manufacturer, Mondelez said it had changed the shape “to keep the product affordable”. It said it was experiencing higher costs for “numerous” ingredients.
But on Monday, the ONS cast doubt on whether input costs really are rising. It said the import price of sugar for European companies is close to its lowest level on record, while cocoa prices have fallen sharply since reaching a high in 2015.
Brexit has also made little difference to the shrinkflation trend, which long predates the EU referendum, the ONS said.
“Manufacturers' costs may also be rising because of the recent fall in the value of the pound - leading some commentators to attribute shrinkflation [to] the UK's decision to leave the European Union,” the ONS said.
“But our analysis doesn't show a noticeable change following the referendum that would point towards a Brexit effect.
”Furthermore, others […]had been observing these shrinking pack sizes long before the EU referendum, and several manufacturers have denied that this is a major factor.“
