Here's an extract from The Worst Journey in the World, Apsley Cherry-Garrard's first hand re-telling of Scott's Terra Nova expedition to the South Pole. The book contains an account of Cherry-Garrard's "winter journey", with two companions, to try to discover a rookery of emperor penguins and bring back some of their eggs. This was a 6-week trip through near total darkness, in temperatures between -40 and -60 degrees centigrade, carrying two heavy sledges. It is possibly one of the most riveting passages ever written in the English language about the hardships of wilderness travel.
But it also contains plenty of interesting information about things like, well, rations. Here's what the three men arranged during the journey:
By taking individually different quantities of biscuit, pemmican and butter we were able roughly to test the proportions of proteids, fats and carbohydrates wanted by the human body under such extreme circumstances. Bill was all for fat, starting with 8 oz. butter, 12 oz. pemmican and only 12 oz. biscuit a day. Bowers told me he was going for proteids, 16 oz. pemmican and 16 oz. biscuit, and suggested I should go the whole hog on carbohydrates. I did not like this, since I knew I should want more fat, but the rations were to be altered as necessary during the journey, so there was no harm in trying. So I started with 20 oz. of biscuit and 12 oz. of pemmican a day.
Bowers was all right (this was usual with him), but he did not eat all his extra pemmican. Bill could not eat all his extra butter, but was satisfied. I got hungry, certainly got more frost-bitten than the others, and wanted more fat. I also go heartburn. However, before taking more fat I increased my biscuits to 24 oz., but this did not satisfy me; I wanted fat. Bill and I now took the same diet, he giving me 4 oz. of butter which he could not eat, and I giving him 4 oz. of biscuit which did not satisfy my wants. We both therefore had 12 oz. pemmican, 16 oz. biscuit and 4 oz. butter a day, but we did not always finish our butter. This is an extremely good ration, and we had enough to eat during most of this journey. We certainly could not have faced the conditions without.
(Pemmican is mostly meat with fruit and berries. The "biscuits" used appear to have been high-energy sources of carbohydrate as Cherry-Garrard mentions sugar and oats a lot, but apparently the recipe was a trade secret and isn't disclosed.) So 12 oz. of meat and berries, 16 oz. of what one must envisage as a kind of flapjack, and 4 oz. of butter was enough to live on per day travelling through the Antarctic during winter carrying heavy sledges. That's around 350 grams / 450 grams / 120 grams, give or take, for metric fans. In other words, call it something in the region of a kilogram of weight per day.