Saturday, March 19, 2011

Refueling the Protein Debate and Questioning Gravity

[I used to blog on a weight loss website, but now I am moving my entries pertaining to low-carb research and other controversial topics over here.  This was originally posted on Jan 28.]


Many thanks to another friend for posting the original information and the link to the article on protein consumption. 
Here's the article that was cited in her blog: 
http://www.thefactsaboutfitness.com/news/exerpro.htm 

I hope that you will "like" my blog, even if you don't like or even understand what I am going to say. I think that we need to jump the conversation to a higher level. 
When I first started reading "The Real truth.." and actually tried to tease out the information, I started to get a bit annoyed. The explanations seemed a little murky, so I decided to find the source. I googled a few lines and found that this article, or portions of it, are posted all over the internet, on sites having to do with all sorts of topics. 
My "beef" with this article mostly has to do with the sloppy way that results are reported in the media, and not as much in the way that many of these studies are designed and/or analyzed. Usually a first problem is that the sample sizes may too small to make sweeping generalizations intended to apply to entire populations not included the original study. Or, the study might have applied to a different group, say, young healthy college-age males. I finally found what I think was one of the articles referenced, and while the sample size was small, I learned other facts that were more disturbing. 
The problem with many of these studies is that they are classic mixture experiments. One group (called a treatment) starts out with a mix of carb:protein:fat, and then one of the macronutrients is changed for the second treatment. But then, to supposedly make everything even, the total calories are kept constant. 
(This is because EVERYBODY knows that if you change the number of calories taken, it certainly affects weight loss. This is a diet dogma, CALORIES IN EQUALS CALORIES OUT that cannot be questioned. It is like gravity.) 
But what is REALLY going on with this experiment is that in an attempt to keep things even, two things have been changed. It's sort of like taking a tube of toothpaste with the cap on and pushing down on one side. It just goes higher up on the other side. 
In this experiment, there are two groups: one with a 60:15:30 ratio of carbs:protein:fat and the other with a ratio of 45:30:30. And, while it is true that the second treatment has twice as much protein by percentage of total caloric intake, it is also true that the second treatment also has 25% less carbohydrate by percentage. 
Stellar results were declared for the second treatment. Was it because of the added protein? Maybe. Was it because of the lowered carb? Maybe. The trouble is, you can't tell. 
The writer had no trouble concluding that it was because of the protein. As I was reading this, plus the quotes by the study's main author, I started to think, "Hey, wait a minute...". 
Now I am going to illustrate my point that mixture experiments can be murky by taking what this author says Dr. Layman said and TWIST it around, just cause I like doing that and I can. An equivalent and equally-valid statement based on the experiment would be: 

"Both diets work because, when you restrict calories, you lose weight. But the people on the lower-carbohydrate diet lost more weight," 
"There's an additive, interactive effect when a lower-carbohydrate diet is combined with exercise. The two work together to correct body composition; dieters lose more weight, and they lose fat, not muscle."

And I am still wondering why Dr. Layman made the statements he did about protein but not about carbohydrate. 
So....... I went looking for more info. Eventually I did find the second article discussed. It had the same problems as the first study. In his study, Dr. Layman did mention in the very first part that the the diet was both a change to a higher-protein AND lower-carbohydrate diet and did mention near the end that the experiment had some design problems and he proposed a different way. 
However, the title of the study, "Dietary Protein and Exercise Have Added Effects on Body Composition during Weight Loss in Adult Women" obviously is biased towards the high-protein conclusion rather than the low-carbohydrate conclusion. Possibly a nod to the the people who funded the study, The National Cattlemen's Beef Association? The Beef Board? Just sayin'.   Or, maybe it is just because doing any kind of paper on about the "evil low carb" idea is career suicide.
And here's the original article:

http://jn.nutrition.org/content/135/8/1903.long
I didn't find the part where Dr. Layman said what was with the quote marks and attributed to him. Perhaps it came from another article he did, or from a seminar, or from another organization, like the Egg Nutrition Center, another organization he works for. Maybe he never even said it, or more likely, it was taken out of context and "spun". 
I'm not even going to comment that much on the third study discussed in the fitness article, only to say that I found the original article and things are even murkier. Explaining what the problem is would make this blog even longer, and as it is, my head already hurts. So, stay tuned for more... And please, hit the "like" button. Thank you for reading this far. 

1 comment:

  1. Hello, I love reading through your blog, I wanted to leave a little comment to support you and wish you a good continuation. Wish you best of luck for all your best efforts. aluminium gravity die casting, aluminium pressure die casting.

    ReplyDelete