I read (well, not every page from every chapter, but most of it, in smart-skimming fashion) Todd Tucker’s book The Great Starvation Experiment. What the Wiki article fails to mention is that these young men were encouraged to not only exercise (primarily walking about the campus; IIRC it was something in the neighborhood of three miles a day, in all sorts of weather), but maintain their original schedules of classes and jobs. Plus, some of them were athletic to begin with, so they were starting out with attractively muscled bodies with little fat. (Others, however, were rather flabby, so it was a varied mix in the study group.) By and large, they found it untenable to maintain these schedules as the starvation kicked in in earnest. The book’s photos make clear what losing some 25% of your body weight does to the typical college-age man who weighed about 150 lbs. to begin with. Many of the subjects successfully lost weight to the point that their ribcages began to show and they convincingly sported that “concentration camp” look.
Although they were being housed, fed, weighed/measured/tested in various ways in the area underneath the old campus football stadium (since demolished), they enjoyed considerable freedom of movement. What’s amazing is that only two of the test subjects cheated by obtaining food on their own outside the confines of their diets.
Unfortunately, the Minnesota experiment proved to be of limited value in providing information to help guide the rehabilitation of the starving millions of WWII, the primary impetus behind the experiment, mainly because it was undertaken several years too late to be of great use. The scientists involved had to rush to produce a cursory, preliminary report that was pressed into service, IIRC, one or two years after V-E Day, but the final report wasn’t published until 1950 (as noted in the Wiki article.)
Nevertheless, the experiment did shed light on various aspects of starvation trauma. Starvation was found to take a greater toll on mental capacity, cognitive functioning, memory, and sleep patterns than had been previously realized. The Minnesota experiment also dispelled a myth that starvation could improve a person’s eyesight; instead, IIRC, some improvement of hearing in some of the subjects was noted. And perhaps most importantly, it was established that, provided a starved person is prevented from fatally overeating in the initial phase of his rehabilitation, once he’s accomplished that critical first phase of recovery, he can be trusted to satisfy his own nutritional and caloric needs without overly close or patronizing supervision – and that allowing those recovering starving people to eat as much as they want allows for faster recovery than imposing a more gradual recovery diet, which is unnecessary and, to the subjects, odious to adhere to.