Comparison of Weight-Loss Diets with Different Compositions of Fat, Protein, and Carbohydrates Full text of research online. Edit Sorry Demi beat me to it and I hadn't noticed.

the diets should include 8% or less of saturated fat, at least 20 g of dietary fiber per day, and 150 mg or less of cholesterol per 1000 kcal. Carbohydrate-rich foods with a low glycemic index were recommended in each diet. I think most of us find that using NATURAL FAT works better.

The diet sheets are set out here.
This is the low carb analysis
high fat, high protein diet (n = 201)
40% Fat, 25% Prot, 35% Carb

How many people here think 35% of energy from carbs is low carbing?