PRAGUE—In most restaurants and taverns across the Czech Republic, a mug of beer is, literally, cheaper than water. The country's health minister wants to change that as he tries to put Czechs on a lower-hops diet.

It won't be easy. Here in the birthplace of pilsner, beer is known as "liquid bread." Czechs drink an average of 37 gallons of the stuff per person per year, the highest per capita consumption in the world and more than double U.S. levels.

Pub patrons go through the sudsy amber liquid so fast that the nation's largest brewer, SABMiller unit Plzensky Prazdroj, maker of famed Pilsner Urquell, delivers beer with the kind of tank trucks used to haul gasoline, and pumps it into bars' storage vats.

"Beer is like mother's milk for adults," said Marek Gollner, a 36-year-old computer programmer and regular customer at the U Zelenku pub in the Prague suburb of Zbraslav. "For a Czech, it's like wine for a Frenchman or vodka for a Russian."

Faced with such attitudes, Health Minister Leos Heger's campaign to make Bohemia a bit less bohemian is starting with baby steps.