According to The Office for National Statistics (ONS) https://www.ons.gov.uk/ as many as 2,529 products have shrunk in size over the past five years, but they are being sold for the same price.
We're familiar with the shrinkage/remodeling of popular chocolates such as Toblerone. Where the 'peaks' were moved.
However, products such as toilet rolls, coffee, chocolate and fruit juice are being sold in smaller packet sizes. The ONS have stated that the 'Shrinkflation' phenomenon has not had an impact on overall inflation figures.
Some recent examples of shrinkage:
Tropicana Orange and Raspberry: was 1 litre, now 850ml - a 15% reduction
Andrex toilet roll: was: 240 sheets, now 221 - an 8% reduction
McVities Dark Chocolate Digestives: was 332g, now 300g - a 9.6% reduction
Dettol Power and Pure bathroom wipes: was 36 wipes, now 32 - an 11% reduction
Brexit has been cited as a cause. Since Brexit, the pound has tumbled against the US dollar, making imported goods more expensive. The ONS states there is no evidence of a Brexit effect on the shrinking size of chocolate bars. However, manufacturers' costs may also be rising because of the recent fall in the value of the pound, hence why some commentators believe shrinkflation is due to the UK's decision to leave the European Union.