How the Most Dangerous Study of All Time Changed What We Know About Weight Loss

For one, it has nothing to do with willpower

Michael Easter


Photo: Wallace Kirkland/Getty Images

In November of 1944, 36 men entered a lab at the University of Minnesota. They were to be the guinea pigs in one of the most extreme and dangerous studies ever conducted.

World War II was raging. But just as many civilians were dying of starvation as were soldiers in battle. These 36 men volunteered to starve to help scientists understand the effects of starvation and how to bring starving people back from the brink.

In the study, the men were forced to walk at least three miles and do two hours of physical labor every day. During the first 12 weeks, the men ate normally (about 3,200 calories a day). The researchers took baseline measurements of their weight, body fat, resting heart rate, blood panels, strength, psychological state, etc, etc, etc.

Then the diet was abruptly cut in half, so the guys ate just 1,570 calories a day for 24 weeks straight. They had to keep walking and working and the scientists continued measuring. The above photos show just how profound the changes were from the outside.

But what happened to the men internally — both to their bodies and minds — is even more important. The lessons don’t just apply to starving people. They apply to the roughly 50 million Americans who go on a diet each year — and they can tell us everything we need to know about metabolism and why 97 percent of those dieters fail.

This is what happens when we start eating less:

We burn less

As the men began to starve, their resting metabolisms didn’t stay at their normal rates. The men went from burning an average of 1,590 calories a day at rest to just 964. (That’s the same metabolism of a 55-pound child.)

Their bodies saved those calories by doing less of the stuff that kept them healthy. Their heart rates dropped by a third and their body temperatures by three degrees, making them feel freezing cold even in the heat. They stopped replacing cells in their blood, skin, and organs. Their hearts shrank an estimated 17 percent, and they lost 40 percent of their muscle.



Michael Easter

Author of The Comfort Crisis // Professor // Writing about physical + mental health, psychology, and living better 1x week //