I came across this article via Bill Lagakos’ twitter feed titled, “Ketogenic low-carbohydrate diets have no metabolic advantage over nonketogenic low-carbohydrate diets,” published out of the American Journal of Clinical Nutrition in 2006.
In this study 20 overweight subjects were randomly placed on ketogenic or non ketogenic low carb diets for 6 weeks and had various biomarkers tested.
The macros of the ketogenic diets consisted of 60% fat, 30% protein, and 5% carbs as percentages of total energy requirement. They started these guys off eating less than 20 gm carbs per day, something Kiefer would’ve been proud of.
The nonketogenic low carbbers ate 30% fat, 30% protein, and 40% carbs. In my mind this still seems pretty high carb. For a theoretical person with a 2000 kcal requirement, this would come out to around 200 gm of carbs.
The reason that this study caught my attention was that one of the biomarkers they tested was serum cholesterol and guess what they found:
several participants following the [ketogenic] diet had marked increases in LDL cholesterol.
Blood β-hydroxybutyrate in the KLC dieters was 3.6 times that in the NLC dieters at week 2 (P = 0.018), and LDL cholesterol was directly correlated with blood β-hydroxybutyrate.
They conclude their discussion by saying:
In summary, differentiating between ketogenic and nonketogenic LC diets is an important consideration for clinical practice because ketogenic diets have been associated with adverse metabolic events including elevated LDL (26) and cardiac complications (36, 37). In the current study, the KLC diet did not offer any significant metabolic advantage over the NLC diet. Both diets were effective at reducing total body mass and insulin resistance, but, because blood ketones were directly related to LDL-cholesterol concentrations and because inflammatory risk was elevated with adherence to the KLC diet, severe restrictions in dietary carbohydrate are not warranted.
Furthermore, the NLC diet was associated with feelings of high energy and a more favorable mood profile than was the KLC diet. Practitioners should advise patients who wish to follow an LC diet to choose low-fat meats and dairy products, 8–9 daily servings of fruit and vegetables, and a dietary carbohydrate limit near 100–125 g/d. Patients should know that there is no apparent metabolic advantage associated with ketosis during dieting.
This is presciently similar to the carb intake I’ve settled on recently, trying to stay in the range of 50-120 gm.