Medary.com

 A large, well-designed study in Israel comes in with the results, via ScienceDaily:

Although participants actually decreased their total daily calories consumed by a similar amount, net weight loss from the low-fat diet after two years was only 6.5 lbs. (2.9 kg) compared to 10 lbs. (4.4 kg) on the Mediterranean diet, and 10.3 lbs. (4.7 kg) on the low-carbohydrate diet. "These weight reduction rates are comparable to results from physician-prescribed weight loss medications," explains Dr. Iris Shai, the lead researcher.

The low-fat diet reduced the total cholesterol to HDL ratio by only 12 percent, while the low-carbohydrate diet improved the same ratio by 20 percent. Lipids improved the most in the low-carbohydrate, with a 20% increase in the HDL ("good") cholesterol and, 14% decrease in triglycerides. In all three diets, inflammatory and liver function biomarkers was equally improved. However, among diabetic participants, the standard low-fat diet actually increased the fasting glucose levels by 12mg/dL, while the Mediterranean diet induced a decrease in fasting glucose levels by 33mg/dL.

Let's see . . . highest weight loss, best lipid (cholesterol) results . . . what more can you ask for?

Low carb diets are the way to go, it would certainly seem.  Somebody get the USDA and the American Heart Association on the line.

(And yeah, I see quite a few similarities between the low fat fetish of the nutrition industry and the global warming extremism of . . . well . . . a lot of folks.  Both are, I believe, fundamentally political viewpoints masquerading as scientific positions and are hence defended with arguments from authority instead of scientific inquiry.  More science, less religion, please.)