This was just caloric restriction in healthy people.
I also would like to mention the Donner Party and the Soccer Team in the Andes , starvation is not a cake walk.
The men in this study were studied for 3 months with their usual diet to test their emotional health prior to starting.
This is the closest thing that there is to a starvation study in a normal humans.
It is only semi-starvation because it is unethical, immoral and illegal to test to the death in a healthy person.
The only medically controlled studies on starvation were conducted by the Nazi's and by the Japanese during the WWII era. We prosecuted those people for war crimes.
For those that would say there is no application in Terri's case, I would like to point out that she is cognitively impaired.
She may not be able to comprehend the meaning of her suffering. Since she with draws from pain, she probably does feel it.