[Subby]

Originally Posted by REDLAN

perhaps before people start getting tooo excited and hailing this as the definitive proof that low carb diets are the answer to diabetes, maybe they ought to check out the abstract on Pubmed first...

-snip-

Only 58% of the study group made it to the end of the study. Bearing in mind this study only ran for 24 weeks, this does not bode well. High dropout rates do characterise ketogenic diets - they aren't tolerated particularly well. High dropout rates matter because they can bias the study's findings. What matters is why they drop out - it could be because they couldn't tolerate the diet, it could be because the diet didn't improve or maybe even worsened their control, it could be because they experienced significant weight regain. The point is that very often people drop out because the treatment does not work/makes things worse/or has unpleasant side effects. This effect can bias the results by making the treatment appear more effective because you are only measuring the people for whom the treatment work i.e. those who stay in.

This is a disingenuous line of argument. The dropout rate was for the ENTIRE study group, no differentiation between the ketogenic or the low calorie group. For all you know all the dropouts were in the low calorie group. Your implicit focus on ketogenic diets as singularly problematic is not founded on information here. It's speculation.

Regardless of which, you'd need to contextualise your argument in term of typical drop out rates in order to make any meaningful point here. For all we know, it's a typical drop out rate for any dietary test.

The second bit concerns the weight loss - compare the 2. after 6 months the ketogenic diet group lost almost twice as much weight as the low GI group (11.1kg versus 6.9kg) There is nothing unusual in this result - low carb diets produce dramatic weight loss in the first 6 months, followed by more rapid weight regain. After 12 months however there is very little difference between a low carb diet and a standard low fat one.

The problem for the study in claiming that it is the ketogenic diet that causes the improvement in HBa1c is that weight loss is strongly correlated with improvement of symptoms for type 2. The differences in HbA1c reported by the study could be solely due to the differences in weight loss reported by the 2 groups.

Firstly, if the ketogenic diet caused improvement in A1c because it caused weight loss, then to all intents and purposes the ketogenic diet caused the improvement of A1c. Why is that invalidated by being a short chain of events?

Secondly, while a connection appears to be established between becoming less overweight and improving A1c, there is again, no foundation to the claim that it's the sole reason that the ketogenic diet is being effective. Again, this is just speculation on your behalf.

The sole point you present to negate all of these potential benefits is that there is "very little difference between" low/non low carb diets at the one year mark, a statement you don't source in the slightest (nor articulate to a meaningful degree). And lets take for a moment it's true, that the two diets end up with the same results for both weight and for all diabetic indicators at the 12 month mark. What about short term gains? In the event the ketogenic diet results in a much faster normalisation of A1c, why is that invalidated?

Actually, you do cite a source in a moment, lets talk about it there...

When it came to comparing low-fat versus low-carb diets, they concluded that 5 out of the six studies that were eligible for inclusion were at high risk of bias - i.e. poorly designed and implemented - and therefore no firm conclusions could be drawn. If however you take time to read the results section, you will discover that long term (12+ months) there was little difference between low-fat and low-carb for either weight loss, or blood glucose control.

The only salient part of the "results" section would be "(b) Studies that assessed low-fat diets versus moderate fat or low-carbohydrate diets", yes?

There is no such assertion about the 12+ month mark, here.

They did however discuss (briefly) the results achieved by Nielsen...

Actually you put in the link for the abstract there, I'd like to quote the only sentence pertaining to the Nielson trial:

Recently, some small-scale studies discussed the importance of dietary composition and low-carbohydrate diets in the management of type 2 diabetes mellitus (Boden 2005; Nielsen 2005). Low carbohydrate diets appeared to have a significant effect on decreasing HbA1c and weight reduction. However, more research is required on larger populations and with a strict control group.

Hardly an indictment. Rather a note of interest, I would say. The number of issues you take up with low carb diets is NOT born out by the Cochrane report. For them it's just not on the map yet to include, due to inadequate testing.

I'm not a low carber, by the way. I do have an interest in the subject and I do think your post seems rather... biased, and verging on dubious at points, which is ironic seeing that you keep referring to "unbiased" information to back you up!