I kind of think this is a stupid question, but just wondering since I don't think that I've ever seen a definite answer.
If your primary concern is fat loss, what would you feel is the MINIMUM amount of heavy strength training required to minimize strength and muscle mass losses? My guess would be two days of heavy, compound movements. Or, a 5/3/1 style approach focusing on one big movement a day with accessory movements.
And as far as 'cardio'. I'm talking sled drags, complexes, etc. Not LSD runs.