150433,
low calorie diets are indeed safe as long as they are nutritionally-dense diets, but on a water-only-fast, if some other foodstuffs are consumed in limited quantities, then this is sufficient to fool the body into believing it is in "eating mode" or on a restricted diet.
Under these circumstances, what many here have referred to as "starvation-mode" is in reality an ultimate and eventual state of malnutrition and the dangers thereof, brought on by reduced nutrients.
It is well-documented for example that a restricted low calorie diet that is deficient in Ascorbate will cause scurvy, but on water-only this does not occur. The same can also be said for most all other nutrients.................... http://www.soilandhealth.org/02/0201hyglibcat/020127shelton.III/020127.ch18.htm