It's not physically possible for a 50% deficit to fail, what you probably mean is that their energy expenditure was incorrectly estimated at +50%.
No, what I mean is that their body's energy expenditure changed in response to the change in their caloric intake, with no other changes taking place.
No, what I mean is that their body's energy expenditure changed in response to the change in their caloric intake, with no other changes taking place.