From: Harvey Newstrom (mail@HarveyNewstrom.com)
Date: Fri May 23 2003 - 11:43:16 MDT
gts wrote,
> I don't think your conclusions after reading the full text in any
> way refute the abstract or the media hype. The media claim from
> the article I cited from the Science Daily site at
> http://www.sciencedaily.com/releases/2003/05/030522083022.htmis is that
> Atkins "May Be As Effective And Safe As Conventional Diets." It is not a
> claim that Atkins is superior to conventional diets.
I know that's what the article said. But the text of the study itself said,
"Longer and larger studies are required to determine the long-term safety
and efficacy of low-carbohydrate, high-protein, high-fat diets." That is,
the study did not find its own results conclusive enough to support this
claim and said better studies were needed to test this claim. The study
also had the disclaimer that, "the results of these metabolic studies should
be interpreted with caution, given the study's relatively small sample size
and one year duration." That is, the study didn't believe some of its own
findings. They even warned that "Additional studies in which more precise
measures" should be taken. That is, they thought that more precise measures
might produce different results.
>
> However Atkins might very well be superior. I note the following
> indications (from the abstract):
>
> Though the difference in weight loss between the two diets was not
> statistically significant, the means were nevertheless very different. On
> Atkins people lost about 4.4% of body weight after one year, while on the
> conventional diet they lost only 2.5% of body weight. So then on average,
> Atkins dieters lost almost twice as much weight as conventional dieters at
> the end of one year.
Aren't you concerned that they didn't control or monitor the food intake and
that the study itself said a lot of people weren't really following the
diet? How can we accept these results after a year when we don't even know
what diet these people were on?
Aren't you concerned that they found no correlation between ketosis and
weight loss? They only found a correlation between calories and weight
loss. They also found that ketosis disappeared after a couple of months on
the Atkins diet. Further, they concluded that the macronutrient ratio of
calories had no effect. Doesn't this refute the entire premise of the
Atkins diet?
> While these results are not statistically significant, they are still
> noteworthy. In addition to the difference between the means, statistical
> significance is function of 1) the standard deviations of measurements in
> the two groups and 2) the number of data points in the study. The greater
> the number of data points, the greater the statistical significance, which
> suggests that if things continued as they were for more than a
> year then the
> Atkins dieters would look very good relative to the conventional low-fat
> dieters. Unfortunately the study ended at one year.
Actually, all of the measurements seemed to converge and get more similar
toward the end of the year. I think this was due to people not following
the diets. However, following the trends would make Atkins and the
conventional diet converge until there was no difference. That is why the
conclusion of this study was that there was little difference, because they
converged so closely to make the difference insignificant. Longer durations
would probably make the diets even more indistinguishable.
> I note also that healthy HDL increased more on Atkins than on the
> conventional diet. I don't have the actual numbers for HDL, LDL, VLDL (if
> any) or total cholesterol (you have the numbers from the full text, I
> suppose) but this seems also to be a result strongly in favor of Atkins.
Actually, not. I was disappointed that the abstract mentioned these good
numbers without mentioning all the bad or neutral numbers. It gave the
false impression that Atkins was superior. Yes, Healthy HDL increased more
on the Atkins diet, but so did unhealthy LDL and so did total cholesterol.
In other words, the high fat diet raised all cholesterol as conventional
wisdom would predict. The conventional diet lowered bad unhealthy LDL and
total cholesterol while raising healthy HDL. This is the effect I would
want; I would not want the Atkins effect of raising all cholesterol.
> That said, I think Atkins is only a half-step in the right direction. I
> applaud the late Dr. Atkins for eliminating agricultural products
> but I wish
> he had taken the next step: the elimination of dairy products.
I applaud him for suggesting high protein and low carbs. I just wish he
would have taken the next step: the elimination of high levels of saturated
fats.
-- Harvey Newstrom, CISSP, IAM, GSEC, IBMCP <www.HarveyNewstrom.com> <www.Newstaff.com>
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