Good point @SurreySenMum26 As has been said, someone is far more likely to be very ill from being 2-3 stone underweight, than they are from being 2-3 stone overweight.
Whilst 2-3 stone overweight is not ideal, most people would not be suffering from illness and ailments carrying that amount of extra weight, and they would have normal energy levels and still be healthy. This would not be the case if you were 2-3 stone underweight.
If I was 2-3 stone underweight I would be 6 stone. I would look incredibly ill and gaunt at that weight, and would be ill a lot more. When I was 7 and a half stone in my late teens when I was dieting very strictly (about one and a half stone underweight) I was always ill, always getting colds and infections, and was always cold.
At 2-3 stone overweight, I would be 11 and a half stone. I have been that weight and look fine at that weight. Also never had any illnesses or health conditions caused be being that weight. I socialised, travelled, played badminton and tennis and went swimming, and worked full time in a demanding job at that weight too. I could barely drag myself out of bed at 2-3 stone underweight, and was always tired.
So yep, being underweight by around 2-3 stone is far more detrimental to your health than being overweight by that amount