It is a misconception a few seem to have. The only chance I think of retaining the low metabolism would be if you underate during refeeding, not providing enough nutrients or good quality food to satisfy and restock after the fast. Then the body would most likely try to preserve what little you were giving it. So our advice here is always to eat according to hunger, don't fill your stomach completely and don't be a slave to mealtimes. Skip meals if you need to but make sure you have a wide variety of raw foods including portions of the fatty foods that many dieters might normally avoid like avocado's and raw nuts to make sure you're feeding your body all it needs.
Dieting can wreck your metabolism, fasting will rebalance it along with all the other systems given the chance.