[JBorrow]

In TFA they state that the weight loss was an incidental part of the experiment and in fact they thought they would gain weight.

[tekla]

As it turns out, the body obeys thermodynamic laws and you will lose weight if you eat less than you burn even if its all starches and sugars.

[aredox]

Except that the body is not a passive black box and can adapt its burn rate - which is partially uncontrollable (meaning: not related to physical exercise, e.g. thermal regulation)

[kevviiinn]

Burn rate for a sedentary 75kg human is 1600-2000 kcal/day iirc. It can't go down to 500 without dropping active tissue

[kevviiinn]

If they honestly thought that while eating 500 calories I would just write off everything else they claim as total nonsense