And your point is?
Ok, the rules are simple, it takes 1 joule of energy to move one kilo one metre, that is the universal truth.
If she is eating 1000 calories a day and still putting on weight then she is in a vegitative state!
People generally undersetimate what they are eating, not diliberately but they tend to forget to add in everything like 5 cups of tea, ho and that mars bar, oh yes and I put 2 spoons of suger on my special K etc etc. In reality I would bet real money that she is eating more than 1000 cals. but does not account for it.
Now people tend to get very angry when this is suggested please don't all I'm saying is, I don''t care what your particular condition for weight gain is, the laws of physics still apply as above.