• Low carb or higher carb—for most people it doesn't matter. Losing fat is about burning more calories than you eat.
• Low fat or high fat—as long as it is essential fatty acids and good fat it really doesn't matter. Good fat in the form of essential fatty acids actually helps with fat loss. Again, it is more about calories than anything else.
• Calories are the reason you gain or lose fat, so it is much more important to count calories.
• Experimenting with macronutrients is a good way to find what works for you, but it still comes back to calories in versus calories out.
• I've personally tried many different macronutrient ratios. All of them worked as long as I paid attention to total calories.

The bottom line is that calories are king in this discussion.  If you eat 4,000 calories and keep a perfect 40/40/20 carb/protein/fat ratio you are still going to gain fat.  There is no doubt in my mind.  The simple formula is still true—you lose fat when the number of calories you consume is less than what you expend on a daily basis.