For more than a hundred years people have known about calories. Cooks a century ago worried about providing enough calories for people who did hard physical labor. A 1915 home economics textbook showed that a lumberman needed more than twice as many calories each day than a shoemaker.
According to the book:
The man who is working at hard physical labor needs more food than the man who sits quietly at his work. Moreover, one working actively out of doors can take foods which are difficult of digestion for the person of sedentary occupation.
A Textbook of Cooking