Effects of a carbohydrate-restricted diet on emerging plasma markers for cardiovascul

[Dodger]

http://www.nutritionandmetabolism.com/content/3/1/19

Richard J. Wood http://www.nutritionandmetabolism.com/graphics/article/email.gif (http://www.nutritionandmetabolism.com/registration/technical.asp?process=default&msg=ce), Jeff S. Volek http://www.nutritionandmetabolism.com/graphics/article/email.gif (http://www.nutritionandmetabolism.com/registration/technical.asp?process=default&msg=ce), Steven R. Davis http://www.nutritionandmetabolism.com/graphics/article/email.gif (http://www.nutritionandmetabolism.com/registration/technical.asp?process=default&msg=ce), Carly Dell'Ova http://www.nutritionandmetabolism.com/graphics/article/email.gif (http://www.nutritionandmetabolism.com/registration/technical.asp?process=default&msg=ce) and Maria Luz Fernandez http://www.nutritionandmetabolism.com/graphics/article/email.gif (http://www.nutritionandmetabolism.com/registration/technical.asp?process=default&msg=ce)

Nutrition & Metabolism 2006, 3:19 doi:10.1186/1743-7075-3-19

Published 4 May 2006
Abstract (provisional)
Background

Increasing evidence supports carbohydrate restricted diets (CRD) for weight loss and improvement in traditional markers for cardiovascular disease (CVD); less is known regarding emerging CVD risk factors. We previously reported that a weight loss intervention based on a CRD (% carbohydrate:fat: protein = 13:60:27) led to a mean weight loss of 7.5 kg and a 20% reduction of abdominal fat in 29 overweight men. This group showed reduction in plasma LDL-cholesterol and triglycerides and elevations in HDL-cholesterol as well as reductions in large and medium VLDL particles and increases in LDL particle size. In this study we report on the effect of this intervention with and without fiber supplementation on plasma homocysteine, lipoprotein (a) [Lp(a)], C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-alpha).

Methods

Twenty nine overweight men [body mass index (BMI) 25-35 kg/m2] aged 20-69 years consumed an ad libitum CRD (% carbohydrate:fat: protein = 13:60:27) including a standard multivitamin every other day for 12 wk. Subjects were matched by age and BMI and randomly assigned to consume 3 g/d of either a soluble fiber supplement (n = 14) or placebo (n =15).

Results

There were no group or interaction (fiber x time) main effects, but significant time effects were observed for several variables. Energy intake was spontaneously reduced (-30.5%). This was accompanied by an increase in protein intake (96.2 29.8g/d to 107.3 29.7 g/d) and methionine intake (2.25 0.7g/d, to 2.71 0.78 g/d; P < 0.001). Trans fatty acid intake was significantly reduced (-38.6%) while dietary folate was unchanged, as was plasma homocysteine. Bodyweight (-7.5 2.5 kg) was reduced as was plasma Lp(a) (-11.3%). Changes in plasma Lp(a) correlated with reductions in LDL-cholesterol (r = .436, P < 0.05) and fat loss (r = .385, P < 0,05). At wk 12, both CRP (-8.1%) and TNF-alpha (-9.3%) were reduced (P < 0.05) independently of weight loss. IL-6 concentrations were unchanged.

Conclusions

A diet based on restricting carbohydrates leads to spontaneous caloric reduction and subsequent improvement in emerging markers of CVD in overweight/obese men who are otherwise healthy.

[Whoa182]

Very nice to see a bunch of studies being published lately!! :)

I like that fact that low carb does lead to a reducation in calories :thup: but then I can bring up what me and some others we discussing in another thread. Which gave the most benifits, was it the reduction in carbs or the reduced caloric intake. In the end I don't see why it matters that much because atleast it shows low carb IS an effective way of losing weight and reducing calories (which is known for its life extending effect)

So those pigging out on food just because they 'can' on low carb, might not be doing themselves a favour?

Calorie reduction can benifit people in the absence of Carb restriction but can carb restriction have as much benifits without spontaneously reducing intake by a significant amount!

[kyrasdad]

Whoa, refresh my memory. What's your daily caloric intake?

[Whoa182]

At the moment 1800k/cal a day and will one day get down to 1550 (in a few years)
why?

[kyrasdad]

At the moment 1800k/cal a day and will one day get down to 1550 (in a few years)
why?

I'm really getting it off topic here, but I thought that was what I remembered you saying in another thread. To me, that's not an extremely low amount. It's restricted, but there are many days I get fewer than 1800. I've always known that low carb was a gateway to low calorie, and that it allowed me to keep calories significantly lower than I'd have been able to otherwise.

Why are you considering a reduction?

[kebaldwin]

They need to print a million of these studies and duct tape one to the forehead of every health practicioner in the world.

[Katy131]

I love to see these studies published too. :cool: It makes me feel so good .. and vindicated after all these years! :thup:

What bothers me, though, is that I find these studies on the net because I am looking for them. They are not reported on mainstream news (at least I haven't seen them). I don't read newspapers much but I feel sure I would have heard about them from people who do if they were given any air- or print-time. They are not published or given air-time because they do not fit into the accepted view of a healthy diet. Low fat is so ingrained into the modern brain there is no way in for good sense, it seems - or even good radical new studies! :rolleyes:

What changes can be made on the large scale if this new stuff is never read by people who need to know it??

[JL53563]

I love to see these studies published too. :cool: It makes me feel so good .. and vindicated after all these years! :thup:

What bothers me, though, is that I find these studies on the net because I am looking for them. They are not reported on mainstream news (at least I haven't seen them). I don't read newspapers much but I feel sure I would have heard about them from people who do if they were given any air- or print-time. They are not published or given air-time because they do not fit into the accepted view of a healthy diet. Low fat is so ingrained into the modern brain there is no way in for good sense, it seems - or even good radical new studies! :rolleyes:

What changes can be made on the large scale if this new stuff is never read by people who need to know it??

I agree. This p*sses me off to no end. The results of these studies are out there, but you have to go searching for them to find them. However, you can't turn on the TV or pick up a newspaper without hearing about the benefits of a low fat diet, or the evils of "artery clogging saturated fats".

[kwikdriver]

So those pigging out on food just because they 'can' on low carb, might not be doing themselves a favour?



In fact, it's very hard to pig out doing low carb. I can't do it, in fact; even on my highest calorie days I'm still at a deficit. Someone a lot smaller than me might be able to overeat, maybe get to 3,000 calories on occasion, but I just don't see how anyone could consistently overeat doing this. It really puts the kibosh on appetite -- when done correctly.

[LC_Dave]

What bothers me, though, is that I find these studies on the net because I am looking for them. They are not reported on mainstream news (at least I haven't seen them).

This annoys me no end as well! Jimmy Moore says the Mainstream Media have declared Low Carb as dead.

Whereas it's very much alive and multiplying!

I had a search on google news for 'low carb'. 99% are the articles are from Jimmy Moore.

Is there a conspiracy ? The answer would be yes!!

[Abd]

Subjects were matched by age and BMI and randomly assigned to consume 3 g/d of either a soluble fiber supplement (n = 14) or placebo (n =15).

I had overlooked this at first. It looks like this study was intended as a controlled experiment to determine the effect of fiber supplements. It is interesting that those supplements had no apparent effect on the studied markers; the conclusion about the effect of carb restriction on overall caloric intake in an otherwise ad libitem diet (i.e., as much as you like except for carbs) is actually a reasonable -- even strong -- hypothesis from the experimental results, but there was no control for this. That is, there was no matched group of subjects *not* on the low carb diet, and either on no diet or another kind of diet, such as low-fat.

Nevertheless, the results are striking, and confirm what many have been saying for a long time: low carb diets are not necessarily isocaloric; in particular, if the carbs eliminated are replaced with fat, caloric intake may be spontaneously reduced. On the average, it would be interesting to see the variation, the range among subjects. From what is written here on lowcarber.org, some people need more than carb restriction, and some do not.

The results place in serious doubt all the objections to LC diet based on "a calorie is a calorie." Even if a calorie *were* simply a calorie, which is not the case. (That is, food calories, as found on labels, are not thermodynamic calories, but are derived from them by a series of assumptions that can be flawed.)

Indeed, the distinction is so fundamental that we must suspect the education and knowledge of all those who have made the claim. It is one thing for a member of the general public to make that mistake (I made it for a long time, posting, for example, that "human beings are not bomb calorimeters," as if food calories were what you find in a bomb calorimeter), and it is another for an expert to make it, which many have.

I knew that food calories were actually kilocalories, but I did not know about the Atwater factors, the presumed food-specific calorie conversion ratios, determined something like a century ago through a series of experiments by Atwater, and which do not consider *at all* dietary context, i.e., the interactions between foods. If fat and carbs are consumed together, is there any shift in the caloric contributions of each, as compared to consuming either alone? Atwater deliberately tried to eliminate that variable, since it could get *very* complicated.

Indeed, this points to a general problem with science when it is used to develop public policy (and I do think that public policy should not be based on other than clear knowledge, when possible, and science is an attempt to clarify knowledge). The general method of science is to isolate variables, in order to determine the contribution of each alone to some result being studied. In doing this, the interactions between variables may be missed.

For example, an epidemiological study that considers dietary fat contribution to, say, blood cholesterol, may lump together diets which vary greatly in something like percentage of trans-fat, saturated fats, so-called good fats, etc. If any one of these has a strong influence on blood cholesterol, it will appear that dietary fat, per se, affects blood cholesterol, and this is exactly what Keyes found in the study that was probably responsible for the general opinion that fat is bad for you.

The "fat is bad for you" opinion was really untenable, since fat is an essential nutrient, so the theory became more specific, that there are good fats and bad fats, which is probably true. But identifying saturated fat as a culprit was apparently not based in solid science. Used to be that they deep-fried french fries in lard. Because lard is highly saturated, and, big plus for fast-food conglomerates, artificial trans-fats were less expensive, a shift took place to frying in trans fats. Since trans fats are likely to be the worst possible fat, from the point of view of increasing CVD risk, the public health may have been seriously damaged from the advice to move away from saturated fats.

(I'm glad they are not using lard, because I'm a Muslim, but that is entirely a different matter. I'd rather they use another saturated fat, probably of vegetable origin. But I still wouldn't be eating many french fries, not because of the fat, but because they are made from potatoes! I'd treat them like I treat most desserts: something I can eat once in a while, as a treat. Not as a filler and common supplement to a meal.)

[kwikdriver]

(I'm glad they are not using lard, because I'm a Muslim, but that is entirely a different matter. I'd rather they use another saturated fat, probably of vegetable origin. But I still wouldn't be eating many french fries, not because of the fat, but because they are made from potatoes! I'd treat them like I treat most desserts: something I can eat once in a while, as a treat. Not as a filler and common supplement to a meal.)


McDonald's used to use tallow. I don't know of any of the large chains that used lard, although there might have been a few. They'd probably go back to tallow and palm oil if people got on them about the trans fats, but I don't see a groundswell of outrage out there. There's too much confusing information (I wonder how that happened) for the average person to sort through.