We aren't going to know exactly what Martin does until he writes his book, but I've been doing the following:
Assuming 2800 calories = maintenance:
Off days: eat ~2300 calories, high protein, low carb, remainder fat. Martin recommends making the first meal the biggest; I do the last meal biggest so I can eat normally with the family.
On days: eat 2800-3000 calories. Since I train in the evening, first meal is about 300 calories very high protein, second meal is about 3-400 calories, with some fruit, after training meal is big :-), meat and root vegetables for me, mostly.