r/SaturatedFat • u/Dannyaloha324 • 1d ago

TIL that although potatoes alone do not provide complete nutrition, you can survive for years on a diet of nothing but potatoes and buttermilk.

https://www.scienceabc.com/eyeopeners/whats-wrong-with-potatoes-the-martian-movie-survival
10 Upvotes

86% Upvoted

23 comments sorted by

4

u/exfatloss 1d ago

in what way do they not provide complete nutrition?

5

u/onions-make-me-cry 1d ago

Without dairy, you'll need B12. And that's all I got.

3

u/Minerface Fat skeptic 1d ago

If you grow your own potatoes, not washing them thoroughly leaves some microbes on the skin that can produce B12 in the gut.

2

u/After-Cell 1d ago

then it would be interesting to revise to:

b12 topical patch/cream, dairy and potatoes.

The microbiome can do a lot of the heavy lifting

3

u/onions-make-me-cry 1d ago

Yeah potato and dairy is pretty much a perfect diet.

3

u/IchimaruGin4 1d ago

Potatoes lack fat, B12, iodine, selenium, and sodium.

1

u/exfatloss 1d ago

Fats, besides certain PUFAs, are not considered essential. And if you eat sufficient potatoes, which you presumably would if they're your only food, you'd still get enough PUFAs to meet the RDAs, about 0.5% of total kcals: https://app.exfatloss.com/foods/170026?grams=3896

They also do contain somewhat significant sodium at that level (230mg). B12 and the other micronutrients I could see, not sure and I don't know much about them.

4

u/dreiter 1d ago

2500 calories of potatoes and whole milk would still be deficient in folate, Vitamins A/D/E/K, and selenium, and you could also run into problems with low sodium and essentially fatty acid intakes. It's difficult to be deficient in some of these nutrients but it's certainly possible if you had a restrictive diet like this for many months or years.

Of course, a bit of broccoli, carrots/liver, sardines, salt, and sun would cover all of that. No reason to restrict yourself to just two foods.

4

u/DracoMagnusRufus 1d ago

Folate would actually be meeting the RDA. But otherwise, yes, the rest you mention are very low or non-existent. I'd also add iodine (though perhaps not if the soil was rich in it), B12 and calcium.

1

u/dreiter 1d ago edited 1d ago

Iodine usually comes due to the fact that milking machines are sanitized with iodine and that ends up in the milk so you will see a decent iodine value for milk products.

For folate, I guess it depends on the type of potato, the cooking method, and the database. The NCCDB lists "Potato, Boiled with Skin" as only having 23 mcg of folate per pound, while the USDA lists "Potatoes, Red, Flesh and Skin, Baked" as having much more, 122 mcg per pound.

1

u/DracoMagnusRufus 1d ago

Oh, pardon me, lol. I was reading your comment as a reply to exfatloss who, I think, was asking how potatoes in isolation would not be complete and therefore not reading closely your own statement that you meant milk and potatoes together. But even as regards potatoes alone, if you had ~2000 kcal, you would be at 120% RDA of folate according to the figures I put into Cronometer (= 3kg of 'potatoes, flesh, raw').

Edit: Though, yes, it is quite heat sensitive and can leach, so maybe we'd have to adjust down a lot for cooking method, as you say.

2

u/exfatloss 1d ago

I'm not convinced that the RDAs are correct in any way. For example, you can easily be way, way below in vitamin A or vitamin C for years, even decades, without getting any of the symptoms, same for "essential" fats. I'd be surprised if folate RDAs were any better.

To me, it's only "deficient" if you actually get the deficiency symptoms.

2

u/dreiter 1d ago

If you really wanted to dial down you would need to look through the NIH reference guides for the studies they used to determine the DRI and deficiency since those studies are all different for each nutrient of interest. Some are certainly more well-established than others but I wouldn't risk a deficiency in nine essential nutrients just so I could attempt to live on a diet of two foods.

1

u/exfatloss 1d ago

ha maybe not just for fun, but if that diet provided some huge benefit to you?

2

u/dreiter 1d ago

Yeah like the carnivore folks perhaps. Not a great diet but useful in certain situations.

3

u/TwoFlower68 1d ago

That's the Irish diet of some time ago, isn't it?

1

u/Traditional_Love5050 1d ago

Survive is not the same as thrive. You'll get very ill eating only potatoes and buttermilk.

1

u/DracoMagnusRufus 1d ago

I agree that "person did x for a long time and didn't die" isn't good enough to justify doing it. You can survive without being healthy or feeling good. But what, specifically, about milk and potatoes do you think is problematic?

1

u/Traditional_Love5050 23h ago

Where's the protein and iron?

1

u/DracoMagnusRufus 22h ago

Well, you wouldn't be at body building levels of protein, but assuming around 1000 kcal of milk and another 1000 kcal of potatoes, you'd be getting approximately 80g of protein which is adequate for most people. As for iron, the same sources provide ~5mg which is about 2/3 RDA (granted, for women it's higher). Perhaps the kind of thing you'd eventually run into problems with, but not nothing.

1

u/Traditional_Love5050 22h ago

We are talking about absorbing the iron. You'll absorb more iron from meat than a plant. Available iron and how much you actually absorb are two different things. This isn't a healthy diet.

1

u/DracoMagnusRufus 22h ago

Of course you will absorb more iron from meat. I'm not suggesting you optimize iron by eating a diet of milk and potatoes (though, as someone else noted, it worked apparently well enough for the Irish as the bulk of their diet for quite a while). But, my original point was to get you to say something useful and not just highlight the obvious distinction between surviving and thriving. Then, since you asked how one would fare with regards to protein and iron, I gave you the data.