El Poder del Consumidor (EPC) filed an unconstituionality claim challenging the Regulation on Health Control of Products and Services in its article 25, which states that -amongst other requirements- labelling on food and non alcoholic beverages should include the content of total sugars. The judge granted the claim, but the authorities appealed and the case got resolved by the Supreme Court.
The Court reversed the judges decision and stated that the articled claimed was not unconstitutional because there is no specific labeling model that is obligatory regarding the sugar content. The only requirement- to that date- was that the label should have complete and coherent nutritional information.
There is a dissent vote on this case, linked in related materials.