Generally, that meme’s specifically making the claim about British food, and originated from US soldiers stationed in the UK during and shortly after the Second World War. Before the war, the UK imported a significant fraction of its food, and a huge amount of spice per capita, but that wasn’t possible when U-boats were sinking merchant vessels, so domestic production and imports switched to getting as many calories as possible so people wouldn’t starve. Obviously, that did a number on the flavour of what people ended up eating, and while some families haven’t noticed they can eat nice food again, most people have.