The only caveat is that this is good for people who are already healthy. If you have metabolic problems then this is bad advice.
I am pre-diabetic. If I eat 500 g of carbs a day, my insulin resistance will get even more out of whack and I will become diabetic. I come from a family of diabetics and there is enough evidence to show that Type-II diabetes has a genetic factor to it.
The more important thing for people to worry about is your metabolic indicators. A diastolic pressure of less than 80, an A1C hemoglobin count of less than 5.6 and a triglyceride/HDL ratio of less than 3 (with at least a HDL count of 40) should be your goal for long term health. Any eating habit that is sustainable on a long term basis that allows you to maintain these metabolic factors should be the goal.
Diet is one part of it. The other is exercise. Especially resistance exercise, not just cardio. Cardio is good for maintaining cardiovascular health. But for a better bang for the time you put in the gym, mix in a variety of strength increasing exercises. I recommend deadlifts, bicep/tricep curls and shoulder press.