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Nutrition Diet, supplements, weightloss, health & longevity

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Old 04-13-2007, 01:18 PM   #1
Paul Raphaelson
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I've become interested in the crossfit perspective on things, but am curious about the faith in the zone diet.

I've done a lot of research on sports nutrition over the years, and have yet to find a single study (clinical or field) that supports any of Dr. Sears' claims. Sears' own research, which he sites frequently, does not appear to have ever been published in a peer-reviewed journal. This is just about the biggest red flag you'll ever find for arousing suspicion.

On top of this, macronutrient ratios are probably the single most studied aspect of nutrition. All the research done over the last fifty years points to the same conclusions: there is NO correlation between macronutrient ratios and weight gain/loss (although some extreme diets may help to suppress appetite slightly). And as far as performance, the ratios that work have been pretty well understood for a long time (and they vary significantly from person to person, activity to activity, situation to situation).

For example, the percentage of fat you need is fairly constant, but cold weather athletes do well with more, as do ultra endurance athletes. The percentage of protein you need varies with lean body mass and the amount of strength work you're doing. The percentage of carbs you need varies with your total aerobic caloric expenditure. Elite endurance athletes will typically consume over 70% of their calories in carbs, while they still consume in the range of 1.5 to 2 grams of protein per kilogram of bodyweight per day (possible because of their immense caloric needs). Strength athletes might be best served by ratios closer to the zone's recommendations. But in any case, there's no magic ratio. Any science that says there is is demonstrably bogus.

Look at what elite athletes in various disciplines are eating. you'll see a lot of variation, and it's all logical when you take into account the various demands of different sports. In the world of endurance sports (pro cycling, for instance) you won't see anything resembling the zone because it doesn't work. And yes, it's been tried. These organizations have physiologists and nutritionists on staff, and are not dumb.

Some references:

http://www.ncbi.nlm.nih.gov/entrez/query.fcgidb=pubmed&cmd=Retrieve&dopt=Abstrac tPlus&list_uids=12569110&query_hl=3&itool=pubmed_d ocsum
(Sears' shaky science)

http://www.ncbi.nlm.nih.gov/entrez/q...arch&DB=pubmed
(ergolytic, not ergogneic)

http://mja.com.au/public/issues/175_...s/roberts.html
(fad diets, explanation of low carb)

http://jan.ucc.nau.edu/exs150-p/150HOhighprotein.pdf
(metabolic effects of low carb diet)

http://www.velonews.com/train/articles/3687.0.html
(macronutrient ratios in competitive cycling)

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Old 04-13-2007, 01:51 PM   #2
Daniel Miller
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Paul,

It will be interesting to see the responses to this. I would tend to agree with what you are saying.

I have tried eating zone and also paleo only to find my performance, mental focus, and opportunities to find "friendly" were all reasons to abandon these attempts.

The nutritionist Loren Cordain (you can pubmed his name) will receives tons of references on this board as he argues that the diet of pre-agraian hunter-gathering humans is the diet that modern humans should adapt (no pun intended) due to acid/base balance, insulin response, and macronutrient harmony with our genome. The last of these points is something that I tend to disagree with.

Although his research is well credentialed and referenced I believe he overlooks the importance of modern day epidemiological evidence of millions of healthy human beings across the planet who eat a plant based diet, that is sufficient in protein, fruits, vegetables, and healthy fats. It seems to me that when a paleo or zone diet is compared to a conventional American diet then either of these two is much better due to many limitations on empty calories in preference for nutrient dense food...not because there is a magic ratio that our bodies best respond to or because whole grain food hurts our health. In addition it both tend to be low calorie until you begin to get upwards of 40-60% of your total calories from fat as would be the case of active people who eat in this manner.

As I said, it will be interesting to see the responses to this thread.

-Dan
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Old 04-13-2007, 02:04 PM   #3
Paul Raphaelson
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Yeah, i'm interested too.

One thing I like to keep in mind is that any time you evaluate research, you need to be examine its relevence to your purposes. There's a crossift truism that "wellness" is a state that's somewhere on a continuum to "fitness," but I think there are many, many exceptions to this. For example, elite athletes with a body fat percentage of 3% to 4% are incredibly fit, but often only barely healthy. Their leanness leads to immune system compromise and they're sick all the time. The enlarged left ventricle of endurance and power athletes actually increases risk of many cardiac conditions. I know some people who climb better than I'll ever climb, but they can barely walk and all their joints are held together with tape!

At any rate, studies that show a certain diet leading to a very healthy general population are great to look at in terms of your overall wellness, but may not tell you much about what to eat on a high altitude climbing expedition, or when you're training to wrestle a bear.

I think the best sources we have right now are clinical and empirical studies designed to evaluate athletes. The good news is that there's a lot of it out there (you mention pub med ... anyone who wants to hone their b.s. detector should familiarize themselves with that site).
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Old 04-13-2007, 02:39 PM   #5
Garrett Smith
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The allegiance to the Zone by CFers, is as I understand it, for two reasons:

It has been "clinically" observed to improve CFing athlete's performance, general health markers, and body composition.

It gives a solid, standardized place to begin. That is the biggest benefit.

I don't eat or recommend nutrition based on the "major" research. Research today is bought and paid for by people standing to make a profit from the findings (which may be a complete lie in the first place). Maybe that's why I don't look, feel, or perform like most physicians/nutritionists/exercise physiologists.

Sears' "science" may be shaky in the view from the ivory towers. Black box says it works. My only issue with Sears is that he can't even seem to bother himself to follow his own nutrition scheme (not uncommon among diet book authors).

This question has been done before.
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Old 04-13-2007, 02:56 PM   #6
Paul Raphaelson
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"It has been "clinically" observed to improve CFing athlete's performance, general health markers, and body composition. "

Do you mean annecdotally observed? It may serve you well, but we have no idea what diet you're comparing it to, or whether your results are relevent to people doing different things. As I said above, there are situations where his formula makes sense. But it's not nearly as universal as he pretends, and his logical arguments don't seem to be supportable.

"I don't eat or recommend nutrition based on the "major" research. Research today is bought and paid for by people standing to make a profit from the findings (which may be a complete lie in the first place). Maybe that's why I don't look, feel, or perform like most physicians/nutritionists/exercise physiologists."

That's a popular belief, but a pretty self-defeating one. Most published research is done by universities in a not-for-profit environment. If you're concerned about a study, it's not hard to find out who did it and who paid for it.

Beyond that, the peer-review process is a strict one. You're not going to get anything into a major journal if your methodology is flawed. And furthermore, if your research shows a major finding, other labs around the world are going to try to duplicate it ... if they can't, your reputation and your career are screwed. It's not like an old boy's club where people can just fudge their data and get away with it.

Skepticism should be raised by people who cite their own research but don't publish it ... people like Sears.

I'd prefer to get my advice from people with real track records, like the nutriitionists and physiologists who create the programs for elite teams.
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Old 04-13-2007, 03:21 PM   #7
Kevin McKay
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All I can say is that when I remove refined carbs from my diet and replace them with whole fruits and vegitables that I see a profound difference in concentration, energy level, and body composition. This is a common theme posted again and again.

I personally believe reduction or replacement of refined carbs is the largest common factor spanning both zone and paleo based on the information I see posted on this board.

My 2 pennies worth of anecdotal observation

Always good to question stuff thanks for the post and interested to see where this leads.

Cheers
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Old 04-13-2007, 03:25 PM   #8
Garrett Smith
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Paul,
Considering this is your fourth post, maybe you'll want to go somewhere else for this info, like the websites of the nutritionists and physiologists you so admire. Why are you here asking your question if you don't like the answer?

If you wish to believe that university research is unbiased, feel free. It is not.

"Clinical" research *is* "anecdotal" research.

As each person is an individual experiment, each person needs to find out what works for them. Trying the Zone for yourself would be the best idea--that's what I did, with a healthy dose of skepticism. I have since evolved my diet, AND it gave me a great place to start my investigation.

You should read the latest CF Journal, where Lon Kilgore, a published exercise physiology PhD, gives the real scoop on why elite strength coaches DON'T listen to what research physiologists have to say (hint: it's nearly worthless in the field--research always is behind the curve).

Maybe Sears' diet isn't applicable across the WIDE spectrum of athletes in vastly different disciplines (ie. OL versus ultra marathoning). Maybe the Zone is great for CFers and what they do, put simply. Maybe that's what created this "allegiance", the fact that it seems to work as a launching platform for fine-tuning (he does mention that in the book, if you haven't read it yet). If you understand that, what is your question again? That's rhetorical, I'm done with this thread.
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Old 04-13-2007, 03:26 PM   #9
Kevin McKay
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To clarify I am not really a zoner more of a paleo guy and actually more of an anti refined guy than anything else.

Glycemic index and obesity.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?itool=abstractplus&db=pubmed&cmd=R etrieve&dopt=abstractplus&list_uids=12081852

Increased consumption of refined carbohydrates and the epidemic of type 2 diabetes in the United States: an ecologic assessment1,2,3
http://www.ajcn.org/cgi/content/abstract/79/5/774

Controlling hyperglycemia as an adjunct to cancer therapy
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=pubmed&cmd=Retrieve&dopt=Abstra ctPlus&list_uids=15695475&query_hl=14&itool=pubmed _docsum

Intake of refined carbohydrates and whole grain foods in relation to risk of type 2 diabetes mellitus and coronary heart disease.
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=1 2166526&dopt=Abstract

Carbs may explain ethnic variations in cholesterol
http://today.reuters.com/news/articlenews.aspx?type=healthNews&storyid=2007-01-1 9T182925Z_01_COL966250_RTRUKOC_0_US-CARBS-CHOLESTEROL.xml
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Old 04-13-2007, 03:46 PM   #10
Eric Lester
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Paul,

"Skepticism should be raised by people who cite their own research but don't publish it ... people like Sears."
Agreed! However, skepticism and outright denial are two different things. The reason so many Crossfitters love the Zone is because it works for us with our goals. I would venture to say a large number of people on the Zone here (myself included!) don't necessarily understand the eicosonoid biology and insulin level science behind Sears' theory. I don't know if his science is all correct, partially correct, or a bunch of hogwash!

However, if the diet works for me (and better than anything else I've tried) then that is enough. I don't care if it is because of eicosonoids or if it is because the Zone has me eating a balanced number of a variety of healthy foods.

A couple of objections to your objections and references. Relative to traditional athletic diets the Zone might be considered "low carb". However, the Zone has more carbs than any other macronutrient, "low carb" does not seem quite an appropriate name. If you wanted to call the Atkins Diet "low carb" I could get behind that.

Also you cite endurance athletes as evidence that the Zone is inadequate for athletic performance. How many Crossfitters are endurance athletes? You say to look at the diets of such athletes. Well, look at the diets of body builders. Each have different goals in mind and use what works best for them. I doubt cyclists would make it on a body builder diet, and I doubt body builders would make it on a cyclist's diet!

Crossfit, of course, is neither. If you want to start a thread criticizing the science behind the Zone then go for it. If you want to start a thread criticizing the Zone as effective for endurance athletes go for it. I think these could both be interesting topics to discuss!

However, those two arguments seem rather unrelated to understanding why so many Crossfitters have an allegiance to the Zone. Which I gather was the point of your first post.
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