Mol Cell Biochem. 2006 Jun;286(1-2):1-9. Epub 2006 Apr 21.
Long term effects of ketogenic diet in obese subjects with high cholesterol level.
Dashti HM, Al-Zaid NS, Mathew TC, Al-Mousawi M, Talib H, Asfar SK, Behbahani AI.
Department of Surgery, Kuwait University, Safat, Kuwait. [email protected]
OBJECTIVE: Various studies have convincingly shown the beneficial effect of ketogenic diet (in which the daily consumption of carbohydrate is less than 20 grams, regardless of fat, protein and caloric intake) in reducing weight in obese subjects. However, its long term effect on obese subjects with high total cholesterol (as compared to obese subjects with normal cholesterol level is lacking. It is believed that ketogenic diet may have adverse effect on the lipid profile. Therefore, in this study the effect of ketogenic diet in obese subjects with high cholesterol level above 6 mmol/L is compared to those with normocholesterolemia for a period of 56 weeks. MATERIALS AND METHODS: In this study, 66 healthy obese subjects with body mass index (BMI) greater than 30, having high cholesterol level (Group I; n = 35) and those subjects with normal cholesterol level (Group II; n = 31) were selected. The body weight, body mass index, total cholesterol, LDL-cholesterol, HDL-cholesterol, urea, creatinine, glucose and triglycerides were determined before and after the administration of the ketogenic diet. Changes in these parameters were monitored at 8, 16, 24, 32, 40, 48 and 56 weeks of the treatment. RESULTS: The body weight and body mass index of both groups decreased significantly (P < 0.0001). The level of total cholesterol, LDL cholesterol, triglycerides and blood glucose level decreased significantly (P < 0.0001), whereas HDL cholesterol increased significantly (P < 0.0001) after the treatment in both groups.
CONCLUSION: This study shows the beneficial effects of ketogenic diet following its long term administration in obese subjects with a high level of total cholesterol. Moreover, this study demonstrates that low carbohydrate diet is safe to use for a longer period of time in obese subjects with a high total cholesterol level and those with normocholesterolemia.
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Study 3: Serum Biomarkers for Cardiovascular Disease with No Restriction on Saturated Fat Intake
The results of these initial studies stimulated our interest to study further the effects of VLCKDs on blood lipids and hormones. We have conducted another study to validate these findings in a similar group of 12 normal weight, normolipidemic men and 8 control subjects who consumed their normal diet (5) .
We used the same diet intervention over a 6-week period, except there were no restrictions on the type of fat, and there was no 3-fatty acid supplementation. Thus, our main dietary aim was to study a free-living VLCKD without any other dietary restrictions.
The VLCKD resulted in a similar carbohydrate intake (8% of total energy) and total fat content (61% of total energy) as our initial study, but higher saturated fat (25% of total energy). We had better success in achieving an isoenergetic diet, but there was still a slight weight loss after 6 weeks (–2.2 kg), again highlighting the difficulty in attaining a true weight-maintenance VLCKD under free-living conditions in healthy normal weight men.
We observed very similar responses in fasting lipids with small but nonsignificant increases in total cholesterol and LDL-C, a strong trend for increased HDL-C (p = 0.066), and highly significant decreases in fasting TAGs (–33%) and postprandial lipemia after the fat-rich meal (–29%). Because an increase in LDL-C is generally considered atherogenic, we decided to measure LDL particle size distribution using a polyacrylamide gel electrophoresis procedure. Smaller LDL particles are more atherogenic and associated with higher risk for cardiovascular disease.
Individuals with a predominance of smaller LDL particles are classified as pattern B, whereas those with larger particles are pattern A. We observed that, in subjects who started with the smaller pattern B profile, there was a significant increase in mean and peak LDL particle size after the VLCKD. This study has provided evidence that carbohydrate restriction was the driving force behind our lipid results in Study 1 (2) and not the type of fat or the 3-fatty acid supplementation. This was also the first of our studies to report a beneficial shift in LDL particle size.
http://www.obesityresearch.org/cgi/content/full/12/suppl_2/115S
Zmieniony przez - ellis w dniu 2006-10-05 13:25:31