To be totally honest, I don't know. I've tried to research this but there are so many people online arguing over it that it's impossible to make a factual judgement. I would advise approaching exercise gradually, building it up and see how you feel and how the scales reflect. Several people on here work out without issue but others have stopped loosing weight. Could be coincidence, might be caused by burning too much off on an already low income of calories. Even the experts can't agree on what starvation mode is and how quickly you go into it. The one thing they do agree on is you don't go into starvation mode from missing one meal, it does take days and a real low income of calories, but that's where they then agree to disagree on everything else. Some claim ketosis is starvation, others state it's not but a fine line between starving and normal where we burn the most amount of fat.
Guess it's an area without much in the way of facts to back up the studies.