You math is wrong. Way wrong. 70lb per week is 10 pounds per day. I'm not sure its feasible for a person to eat that much. Maybe a family could. Maybe.
It's frequently claimed that the average Irish male just prior to the potato famine ate well over 10 lbs of potatoes per day:
On a typical day in 1844, the average adult Irishman ate about 13 pounds of potatoes. At five potatoes to the pound, that’s 65 potatoes a day. The average for all men, women, and children was a more modest 9 pounds, or 45 potatoes.
I have lived almost exclusively on potatoes at several points in my life, and there's just no way. I've watched a bulky manual laborer live almost exclusively on potatoes as well, and still not near 10 lbs a day.
This is kind of inconceivable to me. Is it because I’ve never done enough manual labor to eat 65 potatoes in a day? I can’t imagine even finding the time to cook and eat them.
Arguing against the article, 1/5 lb is a pretty small potato. I just weighed a baseball sized potato I dug last week, and it was 7.5 oz (~1/2 lb, 200 g). So if you are picturing an average baked potato, it's probably only 30 potatoes per day. Which, granted, is still a lot.
Cooking time doesn't strike me as a problem. Boiling 30 potatoes does take somewhat longer than boiling 1 potato because the mass is greater, but it's pretty much boil and forget. Also, the boiling can probably be done by one of those women or children who are only eating 10 potatoes a day!
Probably because they weren't getting enough protein. It's easy to eat carbs forever if you have nothing else because you'll still feel intensely hungry without protein.
And if the calorie count upthread is right, that’s 4550 calories per day purely from potato, not counting any added butter, milk, beans, meat etc! I know people did more manual labour back then, but something seems wrong with that figure.
They may not have had access to much of (barely) higher end foods. I read somewhere that the English, who had conquered them, took away a lot of that sell / use in England, including beef.
Update: Found where I read it - Wikipedia:
[ The Celtic grazing lands of ... Ireland had been used to pasture cows for centuries. The British colonised ... the Irish, transforming much of their countryside into an extended grazing land to raise cattle for a hungry consumer market at home ... The British taste for beef had a devastating impact on the impoverished and disenfranchised people of ... Ireland ... pushed off the best pasture land and forced to farm smaller plots of marginal land, the Irish turned to the potato, a crop that could be grown abundantly in less favorable soil. Eventually, cows took over much of Ireland, leaving the native population virtually dependent on the potato for survival.[41] ]
I used to eat about that much a day when I was running twice a day (and I was losing weight while doing so). Michael Phelps was known for eating 10,000 calories a day.
His math is correct. Also, it's really easy math to verify. It's not surprising either. With the stated yields, you could feed a person. You'd need more for a family.
Of course, the yields could probably be improved in order to get the 140 or so lbs needed to feed a family of 3
When I used to work heavy manual labor I was definitely able to easily put down around 7-8 pounds of food per day. One of my coworkers was into weight lifting and estimated we were burning between 3,000-5,000 calories per day depending on the job.
10 lbs of potatoes is only 3,500 calories. Which, while far in excess of a "normal" sedentary lifestyle, is completely reasonable for people working heavy labor jobs if that's their primary food source.
A typical person eats 3 to 5 lbs of food per day, and that generally includes some very calorie rich meats, dairy, nuts and/or processed foods - not exactly the stuff you'll get in your backyard. You might be able to feed a family on an acre of beans, but not on an acre of generic greens.
A 10lb bag of potatoes isn't really that big. If you take one of those bags, split into thirds, as in three meals a day, that's a bit more than 3lbs per meal. If that's your only source of food, that doesn't seem entirely unreasonable.
On a typical day in 1844, the average adult Irishman ate about 13 pounds of potatoes. At five potatoes to the pound, that’s 65 potatoes a day. The average for all men, women, and children was a more modest 9 pounds, or 45 potatoes.
https://slate.com/culture/2001/03/putting-all-your-potatoes-...
While there are people who doubt these figures, eating 10 lbs of potatoes per day is definitely more plausible than your comment indicates.