In his little parable of the potato, Adam Smith opines that oats are worst (look at the Scottish), wheat a little better (peruse the English), but potatoes … he veritably drools over the Irish:

The chairmen, porters, and coalheavers in London, and those unfortunate women who live by prostitution, the strongest men and the most beautiful women perhaps in the British dominions, are said to be, the greater part of them, from the lowest rank of people in Ireland, who are generally fed with this root. No food can afford a more decisive proof of its nourishing quality, or of its being peculiarly suitable to the health of the human constitution (Wealth of Nations, I.11.41).