LISBON, March 18 (Reuters) - Thousands of protesters filled downtown Lisbon on Saturday to demand higher wages and pensions, as well as government intervention to cap soaring food prices they say are strangling already tight budgets. According to Eurostat data, the minimum wage in Portugal - measured in purchasing power parities and not at current prices - in 2023 is 681 euros a month, the 12th lowest of the 15 European Union countries that have minimum wages. See here for a complete list of exchanges and delays