Staple foods are taxed at a lower rate than say, pesto or chocolate.
That's the EU 'luxury goods' VAT rule coming into play - that maddeningly seems to be interpreted differently according to where you are.
To the original poster - be warned, you'll have to pay VAT and duty when the goods arrive in Poland, and the VAT threshold is way, way lower than it is in the UK. Currently it's 50,000PLN, though there are discussions about raising it to 100,000PLN or higher.
You're not thinking about importing "Hugo Doss" or "LaCoast", commonly seen on dodgy markets? ;)