Separate effects of reduced carbohydrate intake and weight loss on atherogenic dyslipidemia.

Krauss RM, Blanche PJ, Rawlings RS, Fernstrom HS, Williams PT.
Am J Clin Nutr. 2006 May;83(5):1025-31. Related Articles, Links
Children's Hospital Oakland Research Institute, Oakland, CA, and the Life Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA.

BACKGROUND: Low-carbohydrate diets have been used to manage obesity and its metabolic consequences. OBJECTIVE: The objective was to study the effects of moderate carbohydrate restriction on atherogenic dyslipidemia before and after weight loss and in conjunction with a low or high dietary saturated fat intake. DESIGN: After 1 wk of consuming a basal diet, 178 men with a mean body mass index (in kg/m(2)) of 29.2 +/- 2.0 were randomly assigned to consume diets with carbohydrate contents of 54% (basal diet), 39%, or 26% of energy and with a low saturated fat content (7-9% of energy); a fourth group consumed a diet with 26% of energy as carbohydrate and 15% as saturated fat. After 3 wk, the mean weight loss (5.12 +/- 1.83 kg) was induced in all diet groups by a reduction of approximately 1000 kcal/d for 5 wk followed by 4 wk of weight stabilization. RESULTS: The 26%-carbohydrate, low-saturated-fat diet reduced triacylglycerol, apolipoprotein B, small LDL mass, and total:HDL cholesterol and increased LDL peak diameter. These changes were significantly different from those with the 54%-carbohydrate diet. After subsequent weight loss, the changes in all these variables were significantly greater and the reduction in LDL cholesterol was significantly greater with the 54%-carbohydrate diet than with the 26%-carbohydrate diet. With the 26%-carbohydrate diet, lipoprotein changes with the higher saturated fat intakes were not significantly different from those with the lower saturated fat intakes, except for LDL cholesterol, which decreased less with the higher saturated fat intake because of an increase in mass of large LDL. CONCLUSIONS: Moderate carbohydrate restriction and weight loss provide equivalent but nonadditive approaches to improving atherogenic dyslipidemia. Moreover, beneficial lipid changes resulting from a reduced carbohydrate intake were not significant after weight loss.

PMID: 16685042 [PubMed - in process]

This is so misleading!

First of all, they are not comparing low carb diets as they purport to be. If the total calories were, say, 1500, then the 54% carb diet would have 202 gm of carb; the 39% carb diet would have 146 gm carb; and their "very low carb diet" of 26% carb would have 98 gm carb -- none of these are low carb by the standards of any low carb diet I know of.

Second, the trial was very short.

Third, they complicated the issue by restricting saturated fat.

It's as if they designed the study deliberately to "prove" that low carb diets have no significant beneficial effects on blood profiles by testing the wrong diets and calling them low carb.

Allison

Isn't the large LDL the sort that isn't harmful?

The large size LDL particles are the healthy ones.

bike,
They admit that their study was "moderate carbohydrate restriction", not VLCKD.

This abstract is unclear about what happened when. I think it says the 26% carb dieters had improved cholesterol numbers compared to the 54% carb group during the weight loss phase, and the 54% group had some "catch up" improvements during the maintenance phase, to the point where they were no longer significantly different after 4 weeks of maintenance.

Provided of course that you can get your 54% carb dieters to lose exactly as much weight as the 26% dieters by forced calorie restriction. Easier to say than do in the real world.

This seems to counter some other real world studies that showed imrovements in lipids on low carb diets vs low fat diets, even if no weight was lost in either group. If so, overweight people have different metabolisms than ideal weight people. Duh.



The best thing about this study is that it seems LC is finally being taken seriously by lots of different researchers all over the country. Even if some researchers "stack the odds" to prove their agenda, it's usually obvious from the start, and the data can still teach us something. Note, this study comes from Berkeley!

Dr. Eades takes on this study (I think it is this one).

Once again, he finds the researchers have drawn their biases into the conclusions.

http://www.proteinpower.com/drmike/.../05/post_1.html

I seem to remember an interesting comment about this article suggesting that they were thinking of subscribing just to see what it was about. I now can't find that post. Anybody remember?