<p>My guess, is farmers, who would get up early, I am 4am, work hard, then come in for "lunch", which needed to be big and filling, and if you look at the food listed, in Op, that is food easily available on a farm</p>
<p>In Ireland, it is a similar breakfast, call a "fry up" or something</p>
<p>Not light, but then they were farmers, and fisherman who went out early, </p>
<p>Just a guess</p>