[thepete2]

In German, they're still separate words, I think "diet" made its way into German and became "Diät".

[pluma]

Ironically, the wages of government representatives are also called "diets" in German. I'd say "diet" for "Ernährung" just fell out of use at some point and was reintroduced when diet fads became a thing.

[gaius]

The Vietnamese parliament is called the Diet but I don’t think it’s etymologically related.

[sshine]

In Danish there's both "en diæt" (what you eat, permanent) and "på diæt" (on a diet, temporary).

I didn't even think about the fact that that word didn't always have the temporary meaning of the word.

[hvidgaard]

The meaning is more fluent. The doctor can put you on a strict diet with a mealplan "lægen har sat mig på en streng diæt med kostplan og det hele", that isn't necessarily temporary.

[MindTwister]

There is also "slankekur" which more or less translates to "slimming-cure"