I ride a similar, but shorter commute daily into london = 30 miles a day. At weekends i do the same, averaging around 200 miles a week.
Regarding food, i have a troughfull of porridge every morning with dried fruit mixed in and a normal lunch. Then tend to have a double portion at dinner time.
Muscles ached a fair bit over the first couple of weeks, but now its easy and really enjoyable. FYI im 6ft 2" and 13stone, have seen a huge loss in weight and more important fat within the last month of commuting
Best breakfast ever for long energy expending days imo
Best breakfast ever for long energy expending days imo