Over here, now that we've got a "single market" in the EU, you can buy goods in other EU countries and bring them in person into the UK without paying British duties and taxes, so long as they're for your own use and not for re-sale. So there's a continuous stream of cars and vans through Dover, loaded mainly with booze and tobacco, and of course a vast amount of smuggling of booze and tobacco for illegal re-sale.
If we had a "fat tax", we'd soon be seeing under-the-counter sales of potato crisps and chocolate biscuits, and news bulletins would tell of Customs raids and seizures of millions of pounds worth of peanut butter and clotted cream.
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