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Effect of Low Carbohydrate Ketogenic Diet on Lipids

Westman, E.C., Yancy, W.S., Guyton, J.S., "Effect of a Low Carbohydrate Ketogenic Diet Program on Fasting Lipid Subfractions," Circulation, 106(19)SII, 2002, page 727. (Abstract #3582).

Carbohydrate-induced hypertriglyceridemia, a well-described clinical syndrome, may be a contributing factor to the increasing prevalence of metabolic syndrome, which consists of abdominal obesity, high triglycerides, low HDL-cholesterol, high blood pressure, and high fasting serum glucose. This study was conducted to determine the effects of a low carbohydrate ketogenic diet program on body weight and serum lipids in an outpatient setting. This two-arm randomized controlled trial compared a low-carbohydrate ketogenic diet (LC) (<20 grams/day "Atkins type") and nutritional supplements (including fish, borage, and flaxseed oil) to a low-fat, low-calorie diet (LF) overweight/obese, hyperlipidemic (LDL>130mg/dl or triglycerides>200mg/dl) otherwise healthy volunteers motivated to lose weight for six-months. Subjects attended group meetings biweekly for 3 months, then monthly. Outcomes were body mass index (BMI) and serum lipids using an NMR lipoprotein subclass technique. The mean age of subjects was 46 years, the mean baseline BMI was 34.5kg/m2, 75% were female, 80% were Caucasian. The weight loss over six months was 13.8% for LC (n=36) and 8.8% for LF (n=27). The reduction in VLDL for was greater for LC than LF (-49% vs. -17%, p<0.01). Both groups had a 73% reduction in small LDL, an increase in LDL diameter (+5% for LC, and +1% for LF) and a decrease in LDL particle concentration (-7% for LC -16% for LF). The increase in large LDL was greater for LC (+53%) than low LF (+2%), p<0.01). The LC group had a 1% decrease in HDL-C, the LC group had an 8% increase in HDL-C. The reduction in TG/HDL ratio was greater for LC than LF(-53% vs. -6%, p<0.01). Diet , nutritional supplement or exercise compliance could not account for these changes. A low-carbohydrate ketogenic with fish, borage and flaxseed oil supplementation led to weight loss, a reduction in VLDL, and increase in HDL-cholesterol and a change from small to large LDL cholesterol. Due to these favorable effects on weight, VLDL and HDL, this approach may be useful to treat the metabolic syndrome.