cramps and you have zero energy. But these symptoms are fleeting and usually disappear

once we eat our next meal. But what if you had nothing to eat, what happens to your body

when it’s starving?

Hey there, Lissette here for DNews. Starvation occurs when your body is consuming fewer calories

than those required to sustain life. It is most commonly the result of famine, extreme

dieting, complete fasting for a cause, or disease. Roughly one out of every nine people

do not have enough to eat, but despite this widespread problem, starvation is not well

understood. Not because it is not important, obviously, but because it's difficult to systematically

study inanition or the impact of starvation on the body.

The lack of experimental data on the subject is largely due to the fact that it is unethical

to conduct a study that requires participants to go without food. And that its effects depend

on many factors - such as the weight of the person before they began to starve, their

genetic makeup, their health and whether they are drinking water. But what we do know comes

from controversial studies like Minnesota University’s starvation experiment from

the 1940s.

During World War II, famine became a pressing issue for many countries around the world.

At the time, scientists were eager to understand what happened to the human body in the process

of starvation - partly because they wanted to understand how to help patients recover from it.

It is not as simple as allowing someone to eat unlimited quantities of food - this can

actually make recovering patients sick because it’s difficult for the body’s systems

to rapidly adjust to eating food again and because hungry people tend to overeat to the

point of vomiting.

So the scientists at Minnesota University recruited volunteers by offering military

men who had been drafted, the opportunity to participate in their study in lieu of military service.

The 36 men who were finally selected were all healthy conscientious objectors to the war.

They were required to walk 35 kilometers a week (22miles) throughout the entire study.

But during the first 12 week control period, the men’s diets were regulated so that they

would reach an ideal healthy weight before the semi-starvation phase - the second period in the study.

In this semi-starvation period of 24 weeks, the participants caloric intake

was cut in about half - from 3,000 to about 1500 calories. To get them as close to their

goal of a 25% total weight reduction, the researchers adjusted the participants' food portions.

The researchers found, that in this semi-starvation phase, participants went through

a number of changes. Due to extreme weight loss, the men displayed physical symptoms

like protruding ribs, sullen eyes, and gaunt cheeks,

as well as swollen extremities likely from a lack of blood protein production.

Physiologically, their metabolic rates decreased - meaning that their bodies reduced the number

of calories they expended while resting. Their heart rates dropped, temperature decreased,

libido declined, and breathing quieted. It was like their bodies were slowing down to

conserve as much energy as possible.

Psychologically, the men became preoccupied with food - talking, writing, and even dreaming about it.　　

They reported depressive symptoms, irritability, and a lack of interest in everyday activities.

Interestingly, while the men reported cognitive deficits, the tests the researchers

administered did not confirm this. More recent studies on nutrient deficiencies, however, have found

that a lack of adequate nutrition can negatively impact cognitive function.

Although the Minnesota study is over seventy years old, this research is still the most

comprehensive look at how the body tries to cope with starvation. Given that 795 million

people suffer from undernourishment around the world, it’s evident that more research is needed.

But the scientific dilemma is that starving your research volunteers is highly

unethical.

Today, scientists must rely on gathering data from autopsy and case studies -

from sources like victims of war who died of starvation. Through this new data, we have learned that

starvation affects children more intensely. It can permanently affect development - stunting

their growth and they are also more vulnerable to dying - at about 32 days of complete starvation

compared to 70 days for adults. For children and adults alike, autopsy studies have shown

that when death occurs from starvation, the body has completely used up its fat reserves

and about 25-50% of other organs and tissues. This helps explain why the body can suffer

permanent organ damage when undernourished.

But, this isn’t a thing of the past. In fact North Korea, has recently announced to

its citizens that they should prepare for famine. To learn more, check my other episode

on whether North Korea is starving its citizens.

By 2013, the country’s food aid had dropped almost 20-fold.

The United Nations reported in 2015 that 70 percent of North Koreans are food insecure,

and more than a quarter of children under five are chronically malnourished.

As you can see, we cover a wide range of topics, so if you have a science question you’d

like us to answer, let us know in the comments and tag it with #AskDnews.