Originally Posted by Darryl Shaw
Americans did not become the fattest people on Earth by eating too many carbs they got that way by too much of everything.
This is factually untrue. The absolute amount of protein and fat has barely budged over the years (fat went up a bit for men, down for women, 50 kcal difference either way). The increased caloric intake has been of carbohydrates, and particularly of the processed sort (we've also seen a rather profound switch from sources of sat fat - red meat and whole milk - to PUFAs from vegetable oils).
And as I say every fraking time we jump all over someone's simple question with this silly debate, the anthropological evidence is that humans do just fine with varying macronutrient ratios, just not with crap. Which is what Ben said quite rightly (avoid grains and vegetable oils) before this descended into glycogen reloading and fat adaptation, and all that nonsense.
For the endurance switch, to maintain weight loss, LC/low cal with refeeds (normal calories, higher carb) tends to work best, with refeed timing depending on the %BF (longer intervals the higher the %BF), and where carb-ups should be timed for the peri-exercise period (just pre and w/in 45 minutes post) unless you are glycogen depleted (which you shouldn't strive for if you are doing endurance training) in which case they can go somewhat longer.
For best results, you should not switch 100% of your training for total distance events -- sprinting and intervals should be a strong focus as well. And definitely keep up with the weight training, at least for strength maintenance.