In a recent study - Metabolic Effects of Weight Loss on a Very-Low-Carbohydrate Diet Compared With an Isocaloric High-Carbohydrate Diet in Abdominally Obese Subjects, published in the Journal of the American College of Cardiology, researchers reported favorable results for obese adults randomly assigned a low-carbohydrate diet for 24-weeks (six months).
As reported in heartWire, "After six months, isocaloric energy-restricted very-low-carbohydrate, high-fat and high-carbohydrate, low-fat diets produced similar weight loss and substantial reductions in a number of cardiovascular disease risk markers," write Jeannie Tay (Flinders University, Adelaide, Australia) and colleagues in the January 1, 2008 issue of the Journal of the American College of Cardiology.
"Neither diet displayed adverse effects, suggesting diverse dietary patterns, including very-low-carbohydrate, high-fat diets, may be tailored to an individual's metabolic profile and dietary preference for weight management."
The investigators note that while the traditional diet reduced LDL-cholesterol levels, the low-carbohydrate, high-fat diet resulted in greater increases in HDL cholesterol and singificantly larger reductions in triacylglycerol levels (a two-fold greater reduction compared to the traditional low-fat diet).
In fact, if we go to the full-text, we find the researchers went so far as to write "consistent with other recent studies, the VLCHF (very-low-carb high-fat) diet produced greater reductions in TAG and increases in HDL-C than the HCLF (high-carbohydrate low-fat) diet. This suggests that the VLCHF diet as a weight loss strategy may confer the greatest clinical benefits in patients who present with hypertriglyceridemia, low HDL levels, abdominal adiposity, and insulin resistance"
Did you catch that - "greatest clinical benefits" - part?
In the paper we learn that subjects were randomly assigned to either of the moderately energy-restricted diet plans for 24 weeks. For those assigned to the very-low-carbohydrate, high-fat diet, 4% of total calories were obtained from carbohydrates, 35% from protein, and 61% from fat, including 20% of total calories from saturated fat. Subjects randomized to the high-carbohydrate, low-fat diet followed a more traditional macronutrient profile, with 46% of calories obtained from carbohydrates and 30% from fat, including <8% from saturated fat.
Now we all know the American Heart Association insists we must keep saturated fat at less than 7% of our calories because intakes higher than that will kill us (eye roll) - yet here we have stunning improvements with saturated fat intake at/above 20% daily for six months! If you haven't read it yet, Dr. Richard Feinman wrote a good article about saturated fat recently.
So, what gives? It seems the subjects in this study significantly reduced their carbohydrate, and that carbohydrate does matter. Also, this study confirms previous data published that found similar improvements in those restricting carbohydrate.
Slowly but surely more data is coming forward that validates carbohydrate restriction for not only weight loss, but health improvements!