# Why is so little known about Nutrition? **URL:** \ **Category:** Factual Questions\ **Created:** [July 26, 2014, 2:13am UTC](https://boards.straightdope.com/t/why-is-so-little-known-about-nutrition/694073 "2014-07-26T02:13:44Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![Yllaria](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yllaria/32/3452_2.png) [@Yllaria](https://boards.straightdope.com/u/Yllaria)\ **Post date:** [August 4, 2014, 3:48pm UTC](https://boards.straightdope.com/t/why-is-so-little-known-about-nutrition/694073/21 "2014-08-04T15:48:35Z")
> [@jtur88](#): > > . . . I suspect because science has fewer ethical obstructions to doing scientific experimentation on livestock nutrition. And there is more to be economically gained by maximizing understanding of livestock nutrition. Well, it IS harder to get permission to do a carcass summary on humans. And it’s already been mentioned that livestock nutrition isn’t looking for longevity, with the possible exceptions of horses, dogs, and cats. > [@jtur88](#): > > Part 1 – Most of what fills those libraries is contradictory, written by hacks with economic or ulterior motives, in the absence of well-researched scientific data… > > Part 2 – Do we know more about the Periodic Table, or the Food Pyramid, and with what degree of scientific certainty? Part 1 - You’re going to the wrong sort of libraries. Part 2 - The Food Pyramid isn’t science, it’s PR. Serieously, there’s the science and then there’s the advice that everyone, including the government in the case of the Food Pyramid, is giving. The advice is contradictory because different authors or committees dip into the science and take different things out of it, sometimes wildly out of context. Some authors just make their own stuff up, because that’s more fun than research. If you check out a university library, you’ll get much different information than if you just hit a community library. At the university library, you’ll discover that no one uses the food pyramid. They’re using big spreadsheets, which the general public would not be willing to use. It’s hard to get good results with the food pyramid because it’s been extremely simplified compared to real nutrition planning. So people don’t get good results and then the government has to try the next simplified PR program. The purpose of the PR programs is to manipulate people into planning good meals without teaching them nutrition. There’s always going to be a problem with that, no matter what chart you cook up. ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [August 4, 2014, 6:06pm UTC](https://boards.straightdope.com/t/why-is-so-little-known-about-nutrition/694073/22 "2014-08-04T18:06:49Z")
> [@Yllaria](#): > > The purpose of the PR programs is to manipulate people into planning good meals without teaching them nutrition. There’s always going to be a problem with that, no matter what chart you cook up. Right. The food pyramid in all its variations is an example of the [nudge theory](http://en.wikipedia.org/wiki/Nudge_theory). It isn’t intended to be exact, but to give a one-size-fits-all goal that would be good for the majority of people. [Recommended Dietary Allowances: 10th Edition](http://www.amazon.com/Recommended-Dietary-Allowances-Reference-Intakes/dp/0309046335/ref=sr_1_sc_1?s=books&ie=UTF8&qid=1407175175&sr=1-1-spell&keywords=reccomended+dietary+allowances) is the series in which the government summarizes all the best and latest nutrition studies in order to create another one-size-fits-all chart. RDAs are better than no advice at all, but mostly intended to provide minimums to prevent deficiencies rather than the optimum values. Since that hasn’t been updated in quite a while I assume that a different publication has taken its place, but the principle remains. ---
**Author:** ![iljitsch](https://avatars.discourse-cdn.com/v4/letter/i/77aa72/32.png) [@iljitsch](https://boards.straightdope.com/u/iljitsch)\ **Post date:** [August 4, 2014, 6:51pm UTC](https://boards.straightdope.com/t/why-is-so-little-known-about-nutrition/694073/23 "2014-08-04T18:51:33Z")
> [@Exapno\_Mapcase](#): > > RDAs are better than no advice at all, but mostly intended to provide minimums to prevent deficiencies rather than the optimum values. I don’t think that’s true. The vitamin C RDA is something like 60 or 70 mg/day, while 10 is enough to prevent scurvy. 70 is also fairly unrealistic, one good size orange just about delivers that much (53 mg vitamin C / 100 g), but for instance apples are only 6 mg vitamin C / 100 g. Similarly, good luck getting your 1000 mg/day calcium without eating a good amount of dairy products or fish with the bones still in them, not many other foods will reasonably give you the RDA. Seems to me like considering the thread title, they just take whatever seems to be enough and them multiply by 5 to arrive at the RDA. ---
**Author:** ![DrFidelius](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/drfidelius/32/3447_2.png) [@DrFidelius](https://boards.straightdope.com/u/DrFidelius)\ **Post date:** [August 4, 2014, 7:00pm UTC](https://boards.straightdope.com/t/why-is-so-little-known-about-nutrition/694073/24 "2014-08-04T19:00:20Z")
We seem to know enough about nutrition to support 7 billion people to an expected age of 70. What more do you want? ---
**Author:** ![Monty](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/monty/32/47_2.png) [@Monty](https://boards.straightdope.com/u/Monty)\ **Post date:** [August 4, 2014, 8:44pm UTC](https://boards.straightdope.com/t/why-is-so-little-known-about-nutrition/694073/25 "2014-08-04T20:44:46Z")
I thought the government stopped pushing the food pyramid and replaced it by something called “my plate”. ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [August 5, 2014, 1:18am UTC](https://boards.straightdope.com/t/why-is-so-little-known-about-nutrition/694073/26 "2014-08-05T01:18:20Z")
> [@iljitsch](#): > > Seems to me like considering the thread title, they just take whatever seems to be enough and them multiply by 5 to arrive at the RDA. It’s a bit more complicated than that: > [@](#): > > The current Dietary Reference Intake recommendation is composed of: > > ``` > Estimated Average Requirements (EAR), expected to satisfy the needs of 50% of the people in that age group based on a review of the scientific literature. > Recommended Dietary Allowances (RDA), the daily dietary intake level of a nutrient considered sufficient by the Food and Nutrition Board to meet the requirements of 97.5% of healthy individuals in each life-stage and sex group. It is calculated based on the EAR and is usually approximately 20% higher than the EAR > > ``` ---
**Author:** ![Yllaria](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yllaria/32/3452_2.png) [@Yllaria](https://boards.straightdope.com/u/Yllaria)\ **Post date:** [August 6, 2014, 6:37pm UTC](https://boards.straightdope.com/t/why-is-so-little-known-about-nutrition/694073/27 "2014-08-06T18:37:43Z")
> [@Monty](#): > > I thought the government stopped pushing the food pyramid and replaced it by something called “my plate”. Yeah. I heard the news commenting that people misinterpreted putting desserts at the top like that. Of course, that was just a passing news comment. And people who want dessert will say what they need to get it. The [USDA My Plate](http://www.choosemyplate.gov/food-groups/) still concentrates on food groups. The actual[logo is here](http://www.choosemyplate.gov/). You can still get people who overcarb by arguing that potatoes and corn are vegetables. Or who add a lot of butter, dressing, and catsup. Or who have no sense of portion size. But any form of simplification has its problems. The simplest spreadsheets log protien, carbs, and fat. Usually, the next things that get added are sodium, fiber, and cholesterol. From there you either split the fats and carbs into subtypes or you add in vitamins and minerals. Doing all of the above is usually as far as most folks go. There are apps with online databases if you’re interested. At least one phone app will let you enter foods using bar codes. That’s a real time saver. ---
**Author:** ![iljitsch](https://avatars.discourse-cdn.com/v4/letter/i/77aa72/32.png) [@iljitsch](https://boards.straightdope.com/u/iljitsch)\ **Post date:** [August 6, 2014, 7:05pm UTC](https://boards.straightdope.com/t/why-is-so-little-known-about-nutrition/694073/28 "2014-08-06T19:05:57Z")
> [@Yllaria](#): > > You can still get people who overcarb by arguing that potatoes and corn are vegetables. I guess you could call corn (maize) a grain, but potatoes are a vegetable and nothing else. You could do worse than eating lots of potatoes: they contain lots of vitamins, an appropriate amount of carbohydrates (not too much by any means) and they’re even a decent source of protein. (Of course it doesn’t help if you dunk those potatoes in the cheapest seed oil available.) Yes, eating too much carbs is bad. So is eating too much protein and too much fat. You know what all of these have in common? _Eating too much._ As long as you can avoid, that you should be fine. ---
**Author:** ![Chefguy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chefguy/32/138_2.png) [@Chefguy](https://boards.straightdope.com/u/Chefguy)\ **Post date:** [August 6, 2014, 7:28pm UTC](https://boards.straightdope.com/t/why-is-so-little-known-about-nutrition/694073/29 "2014-08-06T19:28:46Z")
> [@DrFidelius](#): > > We seem to know enough about nutrition to support 7 billion people to an expected age of 70. > > What more do you want? He’s 74, if that helps answer your question. ---
**Author:** ![DrFidelius](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/drfidelius/32/3447_2.png) [@DrFidelius](https://boards.straightdope.com/u/DrFidelius)\ **Post date:** [August 6, 2014, 8:26pm UTC](https://boards.straightdope.com/t/why-is-so-little-known-about-nutrition/694073/30 "2014-08-06T20:26:13Z")
> [@Chefguy](#): > > He’s 74, if that helps answer your question. Oh. So he’s looking for the elixir of life, as he feels he is now on borrowed time. Got it. ---
**Author:** ![Yllaria](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/yllaria/32/3452_2.png) [@Yllaria](https://boards.straightdope.com/u/Yllaria)\ **Post date:** [August 12, 2014, 12:51am UTC](https://boards.straightdope.com/t/why-is-so-little-known-about-nutrition/694073/31 "2014-08-12T00:51:38Z")
> [@iljitsch](#): > > I guess you could call corn (maize) a grain, but potatoes are a vegetable and nothing else. You could do worse than eating lots of potatoes: they contain lots of vitamins, an appropriate amount of carbohydrates (not too much by any means) and they’re even a decent source of protein. (Of course it doesn’t help if you dunk those potatoes in the cheapest seed oil available.) . . . This is all true. But it shows how simplifying things by dividing foods into categories like “vegetables” can lead a person astray. Yes, the potato is more than just carbs, presuming that you eat the peal. But if what you eat every night is meat, corn, and boiled mashed potatoes with butter or gravy, (adding bread for the grain) the fact that you can say you’re eating two vegetables and be semantically correct really won’t help you. Whereas if you were using a nutrition spreadsheet or spreadsheet app, you’d be able to judge what your fat/carb/protien intake actually was. Also what your fiber, cholesterol, vitamin, and mineral intake was. What kind of potato it is matters, too. But even the best ones are something like 15 carbs for 1 protein and 1 fiber. Not quite the same as green beans: 2 carbs for 1 protein and 3 fiber. Or spinach: 7 carbs for 5 protein and 4 fiber. Compare to the ratio for pasta: 4 carbs for 1 protein and half a fiber, or sourdough bread: 5 carbs for 1 protein and negligible fiber. Looking at ratios only, a potato is a starch or carb. It doesn’t really matter what other ways you can categorize them, you need to choose your portion size according to how many carbs they contribute. And maybe don’t add them to corn and bread and stuffing at the same meal. ---
**Author:** ![jtur88](https://avatars.discourse-cdn.com/v4/letter/j/e9c0ed/32.png) [@jtur88](https://boards.straightdope.com/u/jtur88)\ **Post date:** [August 12, 2014, 2:01pm UTC](https://boards.straightdope.com/t/why-is-so-little-known-about-nutrition/694073/32 "2014-08-12T14:01:56Z")
> [@DrFidelius](#): > > We seem to know enough about nutrition to support 7 billion people to an expected age of 70. We knew that much 5,000 years ago. We knew enough to support the entire population of a food distribution region with a life expectancy of 70 for those who did not succumb to accident or non-nutrition related diseases. Nobody died 5,000 years ago because their culture did not know enough about nutrition and ate the wrong things present in their environment and discarded the wholesome things. Even wild animals “know” enough about nutrition that their species flourishes wherever there is a source of the correct nutrition, and fails only when causes beyond their control reduce the quantity of such food available. ---
**Author:** ![Jackmannii](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jackmannii/32/311_2.png) [@Jackmannii](https://boards.straightdope.com/u/Jackmannii)\ **Post date:** [August 12, 2014, 2:27pm UTC](https://boards.straightdope.com/t/why-is-so-little-known-about-nutrition/694073/33 "2014-08-12T14:27:03Z")
> [@DrFidelius](#): > > We seem to know enough about nutrition to support 7 billion people to an expected age of 70. > [@jtur88](#): > > We knew that much 5,000 years ago. That alleged “knowledge” didn’t extend to preventing such debilitating and fatal diseases as scurvy, pellagra, beri-beri and rickets. ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [August 12, 2014, 3:17pm UTC](https://boards.straightdope.com/t/why-is-so-little-known-about-nutrition/694073/34 "2014-08-12T15:17:17Z")
> [@Jackmannii](#): > > That alleged “knowledge” didn’t extend to preventing such debilitating and fatal diseases as scurvy, pellagra, beri-beri and rickets. Different knowledge. It’s perfectly possible - I’d say 100% inevitable over all knowledge - at any given time to know A, which is valuable, and not know B, which is valuable in a different way. ---
**Author:** ![Jackmannii](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jackmannii/32/311_2.png) [@Jackmannii](https://boards.straightdope.com/u/Jackmannii)\ **Post date:** [August 12, 2014, 4:38pm UTC](https://boards.straightdope.com/t/why-is-so-little-known-about-nutrition/694073/35 "2014-08-12T16:38:12Z")
“Different knowledge”? Huh? By simply citing common (and commonly fatal) nutritional deficiency diseases which were not recognized long ago, we can refute the nonsensical statement that “Nobody died 5,000 years ago because their culture did not know enough about nutrition”. Hell yes they did. ---
**Author:** ![brujaja](https://avatars.discourse-cdn.com/v4/letter/b/4af34b/32.png) [@brujaja](https://boards.straightdope.com/u/brujaja)\ **Post date:** [August 12, 2014, 5:09pm UTC](https://boards.straightdope.com/t/why-is-so-little-known-about-nutrition/694073/36 "2014-08-12T17:09:20Z")
My mother participated in a large longitudinal (10 years) health study through a particular hospital. They were studying the effect of extremely-low fat consumption. She would eat her huge salads with a teaspoon of dressing, no butter or margarine, lean meats only, etc. After the ten years were up, and the results tabulated, they found that there was no particular benefit to ridiculously-low fat intake vs. a reasonable fat intake. If I’m not mistaken, I believe that the participants had a higher incidence of joint problems. You need a really large cohort over time to get useful results. And every individual’s metabolism really can vary widely. I remember reading about a study where they fed people from one culture with cuisine from another culture that was very different from their own, over a period of time. (i.e., feeding Mexicans a Norweigan diet) The idea was that the meals, although nutritionally comparable to their native diet, were ones that they might not especially like. Then they switched them back to their accustomed food. They found that people were actually absorbing fewer nutrients from the food they didn’t like. ---
**Author:** ![jtur88](https://avatars.discourse-cdn.com/v4/letter/j/e9c0ed/32.png) [@jtur88](https://boards.straightdope.com/u/jtur88)\ **Post date:** [August 12, 2014, 5:38pm UTC](https://boards.straightdope.com/t/why-is-so-little-known-about-nutrition/694073/37 "2014-08-12T17:38:10Z")
> [@Jackmannii](#): > > That alleged “knowledge” didn’t extend to preventing such debilitating and fatal diseases as scurvy, pellagra, beri-beri and rickets. People knew that they should eat foods that would defend them against those diseases, and died only because of an absence of such foods in their food distribution geography. There is evidence from 5,000 years ago of long distance trading in order to bring in known nutrients that were not locally present, and food preservation techniques were developed to ensure a year-round access to them… ---
**Author:** ![Jackmannii](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jackmannii/32/311_2.png) [@Jackmannii](https://boards.straightdope.com/u/Jackmannii)\ **Post date:** [August 12, 2014, 9:54pm UTC](https://boards.straightdope.com/t/why-is-so-little-known-about-nutrition/694073/38 "2014-08-12T21:54:01Z")
> [@jtur88](#): > > People knew that they should eat foods that would defend them against those diseases, and died only because of an absence of such foods in their food distribution geography. This is simply untrue. The nutritional basis of scurvy did not begin to be appreciated until well into the 18th century. Understanding (and widespread adoption of dietary measures) that led to conquering beri-beri, rickets and pellagra had to wait until the 20th century. You need to educate yourself on the advances in nutrition that have occurred in comparatively recent times. ---
**Author:** ![iljitsch](https://avatars.discourse-cdn.com/v4/letter/i/77aa72/32.png) [@iljitsch](https://boards.straightdope.com/u/iljitsch)\ **Post date:** [August 12, 2014, 9:58pm UTC](https://boards.straightdope.com/t/why-is-so-little-known-about-nutrition/694073/39 "2014-08-12T21:58:48Z")
But were those diseases common before the industrial revolution, when people started living in cities on a much larger scale and thus lost much control over their diet? ---
**Author:** ![jtur88](https://avatars.discourse-cdn.com/v4/letter/j/e9c0ed/32.png) [@jtur88](https://boards.straightdope.com/u/jtur88)\ **Post date:** [August 12, 2014, 10:27pm UTC](https://boards.straightdope.com/t/why-is-so-little-known-about-nutrition/694073/40 "2014-08-12T22:27:42Z")
> [@Jackmannii](#): > > This is simply untrue. > > The nutritional basis of scurvy did not begin to be appreciated until well into the 18th century. Understanding (and widespread adoption of dietary measures) that led to conquering beri-beri, rickets and pellagra had to wait until the 20th century. > > You need to educate yourself on the advances in nutrition that have occurred in comparatively recent times. Those are modern diseases, brought on by modern man’s attempts to globalize. Scurvy from long voyages isolated from nutrients, and Beri-beri and Pellagra from efforts to introduce foods (rice and corn) to places where it was not or could not be processed properly to preserve traditional nutrient values. Unsurprisingly, the industrial developments of human culture brought on conditions that required new unprecedented research to accompany them. So, of course, research was not done to address those diseases until they presented… [Previous page](https://boards.straightdope.com/t/why-is-so-little-known-about-nutrition/694073.md?page=1) [Next page](https://boards.straightdope.com/t/why-is-so-little-known-about-nutrition/694073.md?page=3)