Young men who lived on about 1,570 calories a day for 24 weeks stayed ravenous long after their weight came back, with some later eating 11,500 calories in a single day

A tray of watery potatoes, turnips and bread sits on a scale before it ever reaches a plate.

Young men line up anyway.

They have volunteered to live inside a university laboratory, not to ship out to a battlefield.

Their only job is to eat what they are given and let their bodies be measured, week after week.

Nobody yet knows how far hunger can push a healthy mind.

What happens when the food finally comes back turns out to be the strangest part of all.

Why cutting calories in half does something food itself cannot fix

The idea was never cruelty, it was arithmetic. Relief workers heading into a starving postwar Europe needed to know how much food actually brought a starved body back, and nobody had measured it properly. So a physiologist and his lab colleagues built a controlled hunger experiment instead of guessing, tracking weight, strength and mood under a diet they could dial up or down like a thermostat.

Once daily intake was roughly halved, the men’s energy needs fell along with their weight, so rations had to be trimmed further just to keep the loss on pace.

That moving target made simple refeeding useless on its own, which is why the final phase mattered as much as the stated reason for starting, tracking whether appetite and mood ever caught up to the number on the scale.

Picture the room where it actually happened

The setting was the Laboratory of Physiological Hygiene, housed under the stands of the university’s brick football stadium in Minneapolis, with dormitory rooms for the volunteers. The men worked in the lab, took classes and walked set distances every week, so this was ordinary life running on far less fuel than ordinary life needs.

Meals came twice a day, heavy on potatoes, turnips, bread and macaroni, the diet relief workers expected to meet overseas.

Even so, the men described a hunger that reorganized their thinking. Conversations drifted back to food no matter where they started, and food preoccupation became one of the clearest signatures of the semi starvation phase.

The numbers that came out of the logbooks

In the fall of 1944, thirty six healthy young volunteers entered the lab for what became an Army funded study of hunger and recovery. By February of 1945 their intake was cut from about 3,200 calories a day to roughly 1,570. Over the following 24 weeks, most lost more than 25 percent of their body weight.

Many experienced anemia, fatigue, apathy, extreme weakness, irritability, neurological deficits and lower extremity edema, as a later review in the Journal of Nutrition summarized.

Returning to the 3,200 calorie baseline did not undo six months of deficit. In the restricted recovery phase the men were split into groups given 400, 800, 1,200 or 1,600 extra calories, and improvement came slower than expected, enough that the lead researcher concluded rebuilding strength after starvation takes something closer to 4,000 calories a day.

Then came the appetite nobody had planned for. About a dozen men stayed on for extra weeks of unrestricted eating, averaging well over 5,000 calories a day, and on occasion one would put away as much as 11,500 in a single day while still reporting hunger he could not satisfy.

Where the effect faded and where it never quite did

Hunger’s grip outlasted the schedule the researchers had drawn up. The small group left on an unrestricted diet kept eating far beyond normal portions after their weight had technically returned, which suggested the body and the appetite recovered on different timetables.

A related protocol today might borrow methods from the sealed chamber studies that track oxygen use under physical strain, since both expose how slowly a stressed body returns to its old baseline.

Not every man recovered at the same pace, and four never reached the end of the protocol at all. Anemia, fatigue and irritability did not lift the moment food increased, which told researchers that refeeding needed its own careful schedule rather than a single finish line.

Even decades later, the story kept yielding evidence. In 2003 and 2004, 18 of the original 36 were still alive and sat for interviews about what that year had done to them, a long view of human experimentation that the self experiment behind the cardiac catheter never got.

What a wartime diet still teaches a modern kitchen

None of this means modest dieting mirrors starvation, and the gap is worth stating plainly. These men gave up a quarter of their body weight by design, under medical supervision, a different world from an ordinary person skipping dessert.

Still, the pattern holds a small warning worth keeping in a back pocket, documented in the Minnesota Historical Society account of the study.

Cutting calories sharply lowers the energy a body burns, and the hunger that follows can outlast the weight loss itself by months.

The honest caveat is that this was one cohort of healthy young men eight decades ago, not a universal rule for every body. But as a record of what sustained hunger actually does, logged meal by meal in a Minnesota lab, it remains one of the most detailed pictures science has gathered, and the survivors tracked down long afterward said, to a man, that they would do it again.