RDA levels and Calories? Who Decided?

(Geoffrey) #1

I belong to a couple of other keto/carnivore forums but this one has the most knowledgeable bunch of people I’ve come across so maybe you can help answer these two questions.

So who decided what the RDA values for optimal nutrition? I’ve heard that the RDA values were just made up by someone studying some college kids without regard to their dietary habits. Any truth to that?

Optimal caloric intake? Who decided what was optimal? I recently heard a podcast where it was said that the conventional wisdom for the proposed calorie limit has been steadily going up over the years and that there was a time, back before the 20th century, that man thrived on about 1500 calories a day. Anyone heard of anything like that?
I would think that it all depends on the individual and their lifestyle.

#2

Optimal caloric intake is easy, it must be whatever we need without sparing due to low-cal… Sometimes maybe a bit more. It’s very stupid to have a fixed number of everyone, obviously. But people like oversimplification so we have those numbers.
I don’t think it went up, I have read books from the early-mid 20th century giving 2500-3000 kcal for everyone (or almost. I know it was definitely significantly over 2000 for most age and gender groups). Over 4000 for physical workers…? They are crazy, I would get obese with those numbers and I have lost fat while eating over maintenance according to calculators (of course one can’t calculate these things, it may give a starting point but it may be very very off).

RDA for various nutrients? No idea where they came from… IDK how good that is for a starting point, of course that is individual too, what we eat works in various ways, it’s not just how much our food contain or even how much we get out of them, certain micronutrients help or block each other to some extent, we know we need much less Vitamin C on carnivore as part of its role can be fulfilled by something else etc.

(Mark Rhodes) #3

5 years out of date and I disagree with @amber on Vitamin C in regards to Lp(a), HOWEVER the information she provides at the one and ONLY International Carnivore Conference was a masterclass of good information on RDA, how they came to be and why they are likely wrong. https://youtu.be/kX4qsJd_Plc?si=xDi_OsL15kUn3P_v

(Bob M) #4

In this video, does she think that something else (a protein, I think) make up for at least part of alleged lack of vitamin C for carnivores? I remember her saying something like this at the last Keto Fest, but I forget exactly what she said.

(Edith) #5

Very interesting history of beginnings of nutrition science and supplementation. I think it is a very balanced perspective.

(You've tried everything else; why not try bacon?) #6

I’ve heard that asserted, but never any reference to back that up. You’d have to search the literature to find out the studies on which the RDA in question is based, and then look at the studies themselves to determine where they found their research population.

The standard caloric intakes have been 2500 kcal daily for men and 2000 kcal daily for women since I was a wee lad (and yes, we did have dirt and sliced bread back then, lol!). I have no reference to back this up, but I suspect that these figures date from the latter part of the 19th century, when caloric intake was just about all anyone could measure. Fifteen hundred calories was considered starvation-level intake when Ancel Keys did his famous experiment toward the end of World War II, and those men became emaciated (literally, not figuratively) on such a diet.

When you read descriptions of meals in older literature, it is clear that people were eating abundantly in general. Of course, there have always been poor people starving to death in every society from classical antiquity onwards, but they have always been considered an aberration, not a good example of a healthy diet.

P.S.–I do happen to know that the RDA for protein was calculated off of a number of studies that measured daily nitrogen loss across a large population. (This nitrogen loss constitutes an absolute minimum need for protein, since the body can assimilate nitrogen only from amino acids, not from the air.)

The average nitrogen loss over the studied population works out to the equivalent of 0.6 g/day/kg of protein. The RDA was therefore set at 0.8 g/day/kg to provide a cushion. The problem with the RDA, which is not a target, but an absolute minimum requirement, is that some people lose a lot more nitrogen than the average, and they consequently have a much higher minimum protein requirement than average.

(Mark Rhodes) #7

If I recall properly from our conversations she ultimately believed the need was less in carnivores. I disagree due to Lp(a) and clotting factors in the heart.

(Bob M) #8

The other problem with RDAs – and there are many-- is that if you were to enter your data of what you eat into a program, you wouldn’t meet the RDAs for probably a lot of stuff.

Yet another problem is that if you were to try to meet your RDAs by, say eating things like spinach, your program wouldn’t consider that you won’t get a lot of what’s on the label due to anti-nutrients, type of nutrient, etc. Take iron, for instance. The type of iron in meat is way more bioavailable than is the type of iron in plants. By a ton. And even in meat, iron isn’t really that bioavailable.

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https://ajcn.nutrition.org/article/S0002-9165(23)24369-5/abstract

That’s the science.

But if you search “good sources of iron”, you’ll see this:

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On “paper”, legumes have this amount of iron, but you won’t absorb much of it.

Edit: Let’s assume you absorb 2% of iron from lentils. That’s .02 (6.6mg) = 0.132 mg. Assuming the RDA (daily value) is correct, you need about 17.8 mg of iron (6.6mg/0.37). To get that from lentils, you absorb 0.132mg per 198 grams of lentils, so 17.8/0.132 * 198g = 26,700 grams of lentils, or 59 pounds of lentils.

100g of beef liver has 4.78 mg iron, absorbed at let’s say 25% or 1.195 mg/100g. 17.8mg/1.195mg*100 = 1,489 grams of liver or 3.3 pounds of liver.

Now, I don’t recommend you eat 3.3 pounds of liver in a day, but if you want to get the “daily value”, that’s what you’d have to eat.

(Joey) #9

@Geezy56 The nutritional RDA framework is a failed construct from the outset.

Even ignoring our capacity as omnivores, the idea of developing meaningful RDA guidelines that are relevant for any particular person at any particular point in time is a hopeless exercise. Only a hapless government agency would even try.

As for any supporting science, the effort reminds me of three statisticians on a hunting trip, shooting at a ten-point buck…

  • The first misses 3 feet to the left.
  • The second misses 3 feet to the right.
  • The third raises his hands in triumph and shouts, “We got 'em!”

:roll_eyes:

(KM) #10

I spent 5 minutes wading through some Important Source which eventually told me that RDA is a formula derived from EAR, which is the amount of nutrient required for precisely half a given population. Someone should whack that a****** on the nose with a rolled up newspaper.

(Doug) #11

I’d say that getting enough nutrients is higher-priority. If that’s taken care of, then whatever keeps us at (or works toward) the desired weight and doesn’t have bad effects.

(Bean) #12

Well, people were smaller. I was recruited to model for a “fashion show” of antique clothing (mostly from my own family) when I was an undersized 11 year old because no adult could fit into clothes from my great and great-great grandparents generations. And these were farmers, carpenters, and a weaver. People who had access to good food and muscle-building labor.

(Doug) #13

This is a lot of it; definitely a factor.

(Geoffrey) #14

Good insight guys. I appreciate it.
The main reason I’m wondering about the calorie intake is that I was talking to a guy I know who is a strict keto eater and has to have 2700 calories a day to maintain his weight. I’m afraid that if I ate that much I’d gain weight. I have to stuff myself just to get 1700 calories. I’m down to a maintenance level and I feel just fine at 1500-1700 calories. Now I eat a pretty strict carnivore diet so all of my calories are nutrient dense.
If I keep losing I’ll definitely try to take on more calories but I think it’s going to take some trial and error to figure this out.

(Geoffrey) #15

Very good talk. Thanks.

(Geoffrey) #16

Yes that was balanced. It showed the initial good intentions and how they got off track nutritionally but then showed how things are starting to change.
Thanks.

#17

RDA’s are the minimums to not develop a problem, they’ve never been about being optimal. Very misleading term they chose to use.

(Bean) #18

I have also been playing with where I am nutritionally. I have known but improving, absorption issues (celiac). I have settled on a surprisingly minimal eating and supplement routine. Once I looked at the type of nutrients and how we absorb them, I realized that some are set much higher than necessary to compensate. Folate and K are good examples, much like the iron example above.

#19

According to my casual readings (I am too curious and sometimes it comes with looking at recipes…), plants are just super awesome and help with everything. World peace is the only thing they may not bring. IDK what was the last green thing where even gaining muscle was mentioned… It wasn’t a protein rich one… BUT it had some amino acids. Yay.

Now that I think about it… No idea where I got my iron. But I was a vegetarian (or almost, so I ate meat a few times per year, less than 1 kg in total) for decades and a woman too and I never had a problem so I surely got enough from something :smiley: I didn’t eat very much legumes, they are very satiating and so much other plants to eat… Oh and eggs. They surely helped (I mean, I don’t know if I got the bigger part of my iron need from eggs alone now that I look at the data).

That would be some serious vitamin A overload… :smiley: I need to held myself back so much due to the way too high vitamin A content of liver :frowning:

Wow… Good for you (but it sounds so little food…). I tend to overeat on every woe, a specialized carnivore may be different (but I can’t stick to that yet). Fat is easy to overeat for me (as it does not much to my satiation beyond helping out protein with the energy minimum) but very high fat isn’t needed for satiation so theoretically I have control over my intake. The problem isn’t hunger like on high-carb!

(Robin) #20

@Geezy56
First, isn’t it absolutely CRAZY that you are now concerned about losing too much weight?! Who’d a thunk it, right?

4 years in now and I struggle to stop losing weight. My body seems to be determined to weigh 130-135 and I want 140-145.
I’m thin enough now that people who have watched me lose weight and cheered me on are now asking if I’m okay. I look sick. Hmmm….

I see my mom’s stick arms, stick legs when I look in the mirror.
I haven’t tracked calories or carbs in ages, but I eat a lot, a lotta lot, all the time. Forget EF, forget the time of day or night, I eat. But I look like a deflated balloon. So I’m adding in some carbs with those calories. Tip toed outside the boundaries of carnivore… shhhh.

Hope you find your sweet spot. Hope we all do.