I think someone posted the NY Times coverage of this paper -- but here is a link to the actual paper.
(Most major universities will have a subscription, so you on-campus types can read it.)
A high-level overview is presented here:
The essence of the study. Examined 811 overweight adults. Fats, proteins, and carb macronutrients were varied by:20, 15, and 65%; 20, 25, and 55%; 40, 15, and 45%; and 40, 25, and 35%. They followed participants for 2 years, and monitored adherence to the diets. They found no differences between weight loss that occurred and the macronutrient ratios.
Obviously, this did not evaluate the effect of training. Nor did it take ratios to very low levels (such as 0-10% for carbs). It may still be possible that even at 35% (their lowest carb level), that these diets are somehow saturating insulin production/sensitivity, and thus weight loss was not as efficient as possible (that is purely speculation).
But if manipulating macronutrient ratios was meaningful to weight loss, then you would expect to see some difference in this study. Oh -- they did not look at body composition either. Just food for thought.
Nice to see a rigorously controlled study.