[dgallagher]

Edit: The number of people jumping on board with this "theory" in his blog comments makes me despair for the state of nutrition and health education.

Most people on the internet have no idea what they're taking about when it comes to food, nutrition, and diets. The same applies to medical advice.

Many people read one thing and repeat it elsewhere, which is an issue if the source was incorrect. Also people love talking about their personal experiences. That's a problem seeing as it's not scientific (no control experiment, only one individual involved, etc...).

A big part of this is that the nutritional industry is not regulated by any body, such as the FDA. You end up with lots of products and advice that adds up to little more than snake oil. Hence fad diets.

What's the best advice to take? That from a doctor, dietitian, or nutritionist. Not some yahoo on the internet.

[Evgeny]

What's the best advice to take? That from a doctor, dietitian, or nutritionist. Not some yahoo on the internet.

Well, that's a good advice in theory, but did you notice how many doctors, dietitians and nutritionists have contradicting points of view?

[dgallagher]

Good point. I'm not sure how many do, but it does happen. I'd love to see data regarding this (e.g. how widespread is it?).

Most doctors are essentially statisticians doing something like this:

1) Formulate a list of patient symptoms, ensuring credibility (e.g. are you lying/hiding/unaware-of something?).

2) Match those up with whatever diagnosis is statistically most likely.

3) Take "medicine X" and see what happens.

4) Cured? If not, go to step 2, repeat.

Step 2 can be subjective, especially if there are several likely causes. This can lead to different doctors giving different diagnosis. The more times a doctor has seen the same problem, the more likely he/she will be correct the first time. Specialists come in handy here, gathering lots of experience regarding only specific conditions.

For rare diseases, hard to diagnose, or those which aren't fully understood, repeating steps #2 - #4 is going to be more likely. This is where you'll find the greatest differences of "opinion".

Step #1 can be repeated too if conditions change, of course.

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Regarding dietitians/nutritionists, I'm not sure how they work. I'd imagine most of their disagreements come from studies contradicting one another. Results of studies can be questioned as well.

There is some overlap with the statistical nature of doctors, though. Pinpointing food allergies/intolerances requires eliminating foods, one-at-a-time, from your diet and seeing what happens. I'm sure there are blood tests which can be done too.

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In general though, it's not wise to discredit professionals just because they may disagree on certain things in their field. Unless the field is fully understood (I'm not aware of one which is!), you'll see that.

Perhaps I should rephrase my advice:

What's the best advice to take? That from "multiple" doctors, dietitians, or nutritionists. Not some yahoos on the internet.

A second or third opinion reduces the likelihood of errors, while limiting received advice only from those educated and qualified to give it.

[Evgeny]

In general though, it's not wise to discredit professionals just because they may disagree on certain things in their field. Unless the field is fully understood (I'm not aware of one which is!), you'll see that.

I'd say that the field is quite poorly understood. Here's an article (long!) that kind of sums it up.

http://www.nytimes.com/2007/01/28/magazine/28nutritionism.t....

What's the best advice to take? That from "multiple" doctors, dietitians, or nutritionists. Not some yahoos on the internet.

A second or third opinion reduces the likelihood of errors, while limiting received advice only from those educated and qualified to give it.

I found out that even after that, I'm tempted to try and do some of my own research, and then apply the advice to myself and see how well it works ...

[dgallagher]

I'll have to read that article when I have some free time. Thanks for the link. :)

While I do like some of the messages and ideas Michael Pollan (author of linked article, plus Food Inc.) is promoting, I always take him with a grain of skepticism. He's correct sometimes, and incorrect or questionable others. A common symptom of someone who's not a doctor or researcher in the field.

I personally classify him in the same arena as Michael Moore. Not to be ignored, but instead to be questioned for every made claim, requiring non-cherry picked studies and scientific research to back him up.

[jules]

You know why? Because the effects are not that big. It's hard to detect small effects.

Here's what I do: I eat whenever I feel like it, whatever I feel like, as much as I feel like. But when I'm full, I stop.

For breakfast this can be:

    - yogurt with banana and jam and sugar
    - slices of bread with cheese and tomato and olive oil heated in the oven
    - a bar of chocolate
    - bread with boiled egg and mayonnaise
    - bread with butter and cheese/jam/other
    - nothing
    - pizza left over from the previous night (home cooked of course ;)
    - any other left overs
    - fruit
    - when I'm hungry, a bowl of pasta

According to every eating school of thought, at least half of these are very bad. Yet I am perfectly healthy. Not overeating (and undereating) is like 10 times more important than what you eat, as long as you get enough of all the nutrients you need.

Don't obsess over what you eat until there is clear evidence. Eat things you like to eat.

[Evgeny]

According to every eating school of thought, at least half of these are very bad. Yet I am perfectly healthy.

What I personally would be worried about is the long-term effects. Unfortunately, these would be very hard to pinpoint as it would be virtually impossible to get enough people to volunteer eating a certain diet, without much fluctuation, for some 30 years or so. And even if such a study would happen, the endless argument would start: "But the diet A contained X, and diet B lacked Y, so obviously we can conclude ..." etc.

Not overeating (and undereating) is like 10 times more important than what you eat, as long as you get enough of all the nutrients you need.

This may or may not be true, and also we could argue about the factor forever. I would say it's way less than 10, especially in the long-term, but I have no way to prove it of course.

Don't obsess over what you eat until there is clear evidence. Eat things you like to eat.

Well, there is the "classic" - "Nutrition and Physical Degeneration" by Weston Price. (Available online at http://journeytoforever.org/farm_library/price/pricetoc.html) He traveled around the world and watched what happened to primitive societies when they introduced western foods in their diets. I read it briefly, and he made an emphasis on dental health, but literally introduction of white flour, sugar, polished rice and canned food produced a huge drop in dental health.

[jules]

> Unfortunately, these would be very hard to pinpoint as it would be virtually impossible to get enough people to volunteer eating a certain diet

Perhaps you don't need to force people to eat certain things. You can observe what they eat and how healthy they are. If you have a large enough sample set you may be able to reach some conclusions. The internet and recent developments on it like things like Facebook may help a lot: if people start recording what they eat on a regular basis you may be able to get a huge and diverse sample quite easily.

> I would say it's way less than 10, especially in the long-term, but I have no way to prove it of course.

From what I've seen I disagree. I know people who eat healthy according to conventional wisdom, but they eat too much. As a result they are fat and unhealthy. I also know people who get at least half of their calories from things that are considered unhealthy like sweets, coke and potato chips, but because they don't overeat they look healthy. Now it's true that body weight is not the only aspect of health, but it is a very big one and the only one that you can measure by looking at somebody...

> I read it briefly, and he made an emphasis on dental health, but literally introduction of white flour, sugar, polished rice and canned food produced a huge drop in dental health.

It's an interesting study but this is not surprising, since bacteria love these things too. Fortunately we have toothbrushes.

That said the study is highly biased. The "native" people are always laughing in the photos and the "modernized" people are looking sad.

[dgordon]

>That said the study is highly biased. The "native" people are always laughing in the photos and the "modernized" people are looking sad.

But this doesn't explain away the order-of-magnitude differences in dental health Price found everywhere he went between people living on traditional diets (who typically didn't have toothbrushes, either) and those living on processed diets.

[jules]

Oh I'm sure that eating those things is bad for your teeth if you don't brush them, simply because the bacteria grow on that kind of stuff (actually I already said this). I'm just saying that the studies sound unscientific; he sounds like he's trying to prove a point.

[drdo]

The problem is that doctor, dietitian, or nutritionist don't even agree with each other.

Also, have you actually checked what the FDA nutritional recommendations are? They are really terrible advice that goes against actual science.

[dgallagher]

The problem is that doctor, dietitian, or nutritionist don't even agree with each other.

Look above for another question I answered, similar to this one, which I posted shortly after you posted yours. :)

Also, have you actually checked what the FDA nutritional recommendations are? They are really terrible advice that goes against actual science.

Any examples?

I think you meant USDA nutritional recommendations:

http://www.cnpp.usda.gov/DGAs2010-DGACReport.htm

In my root comment, I meant regulation of nutritional supplements (which is handled by the FDA). This is different than dietary recommendations (e.g. what quantity of vitamins/minerals to eat).

I'm not aware of any problems there are with the USDA's nutritional recommendations, though I'm sure there are some here and there (please share, I'd love to know!). It wouldn't be fair to discredit the entire document if there is an error, however.

It's a living document too, being updated every few years (the 2005 version should be replaced with the 2010 version soon). As more studies are done and more is learned about nutrition and humans, it gets revised.

[robchez]

The only problem is my doctor wants me to take X drug. My dietitian has type 2 diabetes yet still pushes to eat a grain filled breakfast and my nutritionist wants me to go on a cleansing diet of nothing but vegetables and fruits.

[dgallagher]

The only problem is my doctor wants me to take X drug.

Try getting a second opinion from 1 or 2 other, unrelated doctors. Do they come to the same conclusion or not? Doctors aren't always 100% correct the first time (see my longish-response to another comment in this root thread).

My dietitian has type 2 diabetes yet still pushes to eat a grain filled breakfast and my nutritionist wants me to go on a cleansing diet of nothing but vegetables and fruits.

Lack of communication between the two? I'd get them in the same room together and watch them debate. Also this is another area where a second or third opinion would be good to have.

[robchez]

Some drugs are just pushed harder than others because doctors just don't know (and can't know) all the facts. Take statins for example. My doctor and about 3 others would look at my numbers in a few seconds and just say, well lets get you on Statins. Finally found a doctor who said I can do it via eating well and told me to read Good Calories Bad Calories by Gary Taubes. Here I am years later, cholesterol numbers are literally perfect, and feel great.

I guess you need to be lucky with your physicians.