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> It's not hard to meet that protein goal given the corresponding calorie requirements Just to reiterate the scope of this, it's easy to get sufficient protein

by gralx 8y ago

> It's not hard to meet that protein goal given the corresponding calorie requirements Just to reiterate the scope of this, it's easy to get sufficient protein from plant matter if your protein requirements are nearer the consensus daily minimum of 0.8g protein per 1kg body mass.[1] But it is hard if 1.4g/kg is your goal, as it would be in a power-dominant sport like NFL football. I should have used the exact source of the data you linked to the first time around (mea culpa), which reports a protein mass fraction of 0.0250 [2]: 60kg*1.4g/kg/0.0250=3,360g It is exceedingly difficult to consume 3.3kg of plant matter in a day, assuming these potatoes are representative. Beans are much easier, and even those are hard to sustain at the 1.4g/kg level. Also consider that we're talking about the mass of a female powerlifter here. I believe most women in training would balk at more than three kilograms of plant matter every day. The 95kg, 175cm running back Emmitt Smith would have had to eat 5.3kg of plant matter every day, and he was a smaller man in the world of power athletics. At the minimum daily protein requirement for seniors of 0.8g/kg, the numbers are more palatable: 60kg*0.8/kg/0.0250=1,920g Assuming the protein content of potatoes is representative of plant food generally, an inactive senior citizen could get by on 1.9kg of plant matter every day. Sources: [1] Protein and Amino Acid Requirements in Human Nutrition, World Health Organization, p.114, 2007 [2] https://ndb.nal.usda.gov/ndb/foods/show/11674?fgcd=&manu=&format=&count=&max=25&offset=&sort=default&order=asc&qlookup=Potatoes%2C+baked%2C+flesh+and+skin%2C+without+salt&ds=&qt=&qp=&qa=&qn=&q=&ing= https://ndb.nal.usda.gov/ndb/foods/show/11674?fgcd=&manu=&fo...

firethief 8y ago
Ok, I'm not sure what's going on here. That does sound like a lot of plant matter, but potatoes don't have much fiber or other low-caloric content; they're 3.7 kcal/g dry mass (going by the same Russet data point), compared with 4 kcal/g for pure starch. Is it really such a struggle to get enough calories (and protein) from something with 92% of the energy of pure carbohydrates? Do power athletes normally eat a very high fat diet to get enough calories? In my own experience: I eat 3 meals, generally within an 8 hr window, and it's not unusual for me to cook myself a 1 lb bag of lentils as the major ingredient of any one of them. I don't weigh my prepared food, but comparing usda data for "lentils, raw" vs "lentils, boiled" I'm getting a factor of 3 mass difference for isocaloric quantities; I usually have 1.5-2 x 4 cup bowls of food per meal, which is consistent with the calorie-based estimate of their weight increase on cooking. (Sorry to mix imperial units into it, but I'm surrounded by them!) Translating to respectable units, that comes to over 4kg/day of plant matter. I'm apparently smaller than a female powerlifter and certainly get less exercise; the reason this is an equilibrium amount of food for me is I only eat every other day[1]. I don't have any trouble eating that much, though the quantity of food was daunting when I starting alternate day fasting a few years ago. So, I'm inclined to think that the answer is: what sounds like a huge amount of plants is actually a manageable amount of food once you get used to it; it is a lot of volume, but digestive tracts are adaptable and plants are mostly water. [1]: if I have convinced you yet that I am crazy, please try not to let that cloud your judgment of my reasoning :)
- gralx 8y ago
  After reading about your personal experience, I felt some nagging doubt. I went back to my database to see how much my food would weigh if I set the protein ratio of my diet to 1.4g/kg body mass by increasing the protein-rich bean and grain meals. The total mass of food eaten per day would come to 2840g. That would be sufficient protein for hard weightlifting, and it sounds doable. But my experience was different. At 1.1g/kg I found it too hard to eat the amount of food my diet prescribed. I would just stop salivating. Then maybe the underlying problem isn't the amount of food but my lame-ass cooking.

by gralx 8y ago

firethief 8y ago

Ok, I'm not sure what's going on here. That does sound like a lot of plant matter, but potatoes don't have much fiber or other low-caloric content; they're 3.7 kcal/g dry mass (going by the same Russet data point), compared with 4 kcal/g for pure starch. Is it really such a struggle to get enough calories (and protein) from something with 92% of the energy of pure carbohydrates? Do power athletes normally eat a very high fat diet to get enough calories? In my own experience: I eat 3 meals, generally within an 8 hr window, and it's not unusual for me to cook myself a 1 lb bag of lentils as the major ingredient of any one of them. I don't weigh my prepared food, but comparing usda data for "lentils, raw" vs "lentils, boiled" I'm getting a factor of 3 mass difference for isocaloric quantities; I usually have 1.5-2 x 4 cup bowls of food per meal, which is consistent with the calorie-based estimate of their weight increase on cooking. (Sorry to mix imperial units into it, but I'm surrounded by them!) Translating to respectable units, that comes to over 4kg/day of plant matter. I'm apparently smaller than a female powerlifter and certainly get less exercise; the reason this is an equilibrium amount of food for me is I only eat every other day[1]. I don't have any trouble eating that much, though the quantity of food was daunting when I starting alternate day fasting a few years ago. So, I'm inclined to think that the answer is: what sounds like a huge amount of plants is actually a manageable amount of food once you get used to it; it is a lot of volume, but digestive tracts are adaptable and plants are mostly water. [1]: if I have convinced you yet that I am crazy, please try not to let that cloud your judgment of my reasoning :)

gralx 8y ago
After reading about your personal experience, I felt some nagging doubt. I went back to my database to see how much my food would weigh if I set the protein ratio of my diet to 1.4g/kg body mass by increasing the protein-rich bean and grain meals. The total mass of food eaten per day would come to 2840g. That would be sufficient protein for hard weightlifting, and it sounds doable. But my experience was different. At 1.1g/kg I found it too hard to eat the amount of food my diet prescribed. I would just stop salivating. Then maybe the underlying problem isn't the amount of food but my lame-ass cooking.