They ran the experiment twice; the second time taking the antioxidants C and E. Those taking the daily supplement were relatively sheltered from oxidative stress and did not receive the same benefits from fasting as from the first experiment without antioxidants. Their cells did not respond in the same way by increasing their natural defences and improving their sensitivity to insulin and other stress signals.
A very poor summary but in conclusion, low levels of environmental stress on our 'repair' days might be good for us. Detail is here. http://theconversation.com/feast-then-f ... ress-38808