What Does Hunger Do to Your Brain?

Every Tuesday and Thursday when I got off my classes at 1pm last semester, I would always scuttle back to my room with my head kept low. I didn’t want attention and I didn’t want to make conversations. There was simply one reason behind my unusually introverted behavior: I was getting “hangry”.

It took me a while to I realize that I suffer from severe “hangry syndrome”. It was surprising to see myself losing patience, losing my sense of humor, losing interest in whatever whoever has to say when I am hungry. The change in my mood before and after a meal is VERY drastic.

So that makes me wonder what causes this feeling of “hangriness”? What is happening to my brain?

This brief video by ASAP Science explains the biological changes when food intake is halted. During our “hangry” period, which is typically the first 6 hours after we stop eating food, our brain is not receiving enough glycogen as energy source. It becomes fatigued, and that causes the feeling of “hangry.” (What If You Stopped Eating?)


But what happens to our brain has to endure longer periods of hunger?

In the famous Minnesota Starvation Experiment, significant physiological as well as phycological changes were observed in the objectors, or the volunteers. The Minnesota Starvation Experiment by Ancel Keys, PhD, and Josef Brozek, PhD, was conducted in an effort to provide scientific and practical guidance for relief workers to rehabilitate those who suffered from famine and starvation during World War II (Baker, D., & Keramidas, N, 2013).



minnesotastarvationexperiment23236 men out of 200 who volunteered were selected as objectors to undergo almost a year-long experiment during which they would have to first lose 25 percent of their original body weight. During the following first three months, they followed a normal diet of 3,200 calories per day. For the following six months, they went into the phase of semi-starvation during which only 1,570 calories were allowed per day. Then three months of restricted rehabilitation period, during which they ate 2,000 to 3,000 calories per day, was carried out, and finally eight weeks of unrestricted rehabilitation during which calorie intake was not restricted (Baker, D., & Keramidas, N, 2013).

During the semi-starvation phase, other than the dire changes in appearance, the objectors experienced decreased strength, stamina, body temperature, heart rate, and sex drive. Psychologically, they became obsessed with food. Because of the persistent state of hunger, they “would dream and fantasize about food, read and talk about food and savor the two meals a day they were given.” More than that, fatigue, irritability, depression and apathy were also observed (Baker, D., & Keramidas, N, 2013).

That’s one example of the stark decline in our physical as well as our psychological health due to starvation. Clearly, when our body is not receiving enough fuels, every part is being affected, including the brain. Psychologically, the objectors in the experiment became obsessed with food. Their conversations, activities and readings were always evolving around food; Cognitively, they reported lower sex drive, fatigue, and irritability. Other than the expressive symptoms, what is happening to our brain inside? Are the substances inside our brains being altered or affected?

To better understand how the matters inside our brain are potentially affected by starvation, we turn to current studies that have examined the structural brain changes among Aneroxia Nervosa patients. Anerocia nervosa is a type of eating disorder where patients engage in extreme dieting and restrict food intake in fear of gaining weight. Patients suffer from a distorted body image and have signifiant low weight that oftentimes causes medical complications. The studies that have used magnetic resonance imaging (MRI) to examine the alteration in patients’ brain matters could shed some light on how starvation or significant weight reduction influence the composition of our brain.

graymatter-whitematterIn the study by Fuglset, Endestad, Landrø, and Rø, they found that specific brain regions are more vulnerable to weight changes than others, such as frontal and temporal lobe cortex — part of gray matter. Significant reduction in gray matter volume was observed both globally and in specific regions like anterior cingulate cortex, supplementary motor area and precuneus (Fuglset et al., 2015).

Gray matter consists of neuronal cell bodies and unmyelinated axons (axons that are not wrapped by myelin, a fatty protein). Their main function is to process and integrate information that is sent to them through white matter, generated by different stimuli (Robertson, 2014). A reduced gray matter volume could cause deficit in different brain functioning depending on the regions.

The volume fluctuation of gray matter during weight reduction and restoration is observed in most studies and it suggests that gray matter is most affected (Fuglset et al., 2015). Although with mixed findings in different studies, most studies show a normalized gray matter volume in different brain regions after patients’ weight was restored (Fuglset et al., 2015).

543648-fig-001More specifically, the gray matter in right dorsal anterior cingulate cortex (ACC) is observed to be influenced significantly among anorexia nervosa patients before treatment(McCormick et al., 2008). The affected ACC is normalized after patients’ weight restoration while some studies still show irreversible impact (McCormick et al., 2008). The dorsal ACC ‘s main functions include cognition and memory . Particularly, abnormal right dorsal ACC volume is linked to perceptual organization and conceptual reasoning deficit. Other possible cognitive functions being damaged due to reduced volume of right dorsal ACC include “verbal and visual memory, visuospatial ability, attentional skills, and executive functioning”  (McCormick et al., 2008).

Most studies suggest that the significant weight reduction in aneroxia nervosa patients contributes to a reduced gray matter volume in the brain, both globally and more noticeable in some regions than others, such as in the right dorsal anterior cingulate cortex. The abnormally smaller area of the right dorsal ACC is shown to cause to deficits in patients’ memory, perceptual organization, reasoning and other cognitive functions.

children-juba(UN Photo/Isaac Billy)

Hunger is a matter of survival. It affects more than what we see physically. When your body is depleted of basic biological fuel, your cognitive functions slows down and your ability to work could be negatively affected. “This isn’t warfare or drought. This is about access and politics and poverty and our willingness to address them,” said Kate Maehr, executive director and CEO of the Greater Chicago Food Depository. We are preliviged to always to be able to grab a bite whenever we feel hungry or “hangry.” But that’s not the case for a lot of people in the world. According to the United Nations, the world needs to produce 50% more of what we are producing now to feed a population of 9 million by 2050. The concurrent degradation and exploitation of our natural capital is only undercutting our ability to do so.

Currently, in Cook County, Chicago, 1 in every 6 people are food insecure — not being able to know when or where they will receive their next meal . Fourty-seven percent of the recipients of the Greater Chicago Food Depository face the difficult choice of either paying for housing or medicine, or for food. Children under the age of 18 make up about thirty-seven percent of the recipients of food pantries and soup kitchens in Cook County (A Just Harvest).

_X5A5477_v1Fortunately, there are always people in the community volunteering to help in the
pantries and donate food. While every bit of effort is needed and appreciaed, we still have to try harder to alleviate the hunger problem in this Chicago. The problem observed by Heidi Stevens, a reporter of Chicago Tribune, is that the amount of the donation surges high during holiday seasons, but then it just kind of stops after that.

But hunger doesn’t stop. Forty-two million Americans are still food-insecure (Feeding America), and that’s something they have to face every day throughout the year. Nonetheless, nowadays large amounts of the donations come in the form of fresh food, so the outpouring amount of food donation during holiday season won’t be able to support the local food pantries in months after the holiday seasons as the food perishes.

AAEAAQAAAAAAAAhhAAAAJDlhMjVlNDNjLTZjY2EtNDRlOC04NWYxLTEzNjBjMTcxYzE3YwGiftAMeal is here as a small step for you to help improve the hunger in Chicago area. GiftAMeal is a mobile app that feeds a meal to people in need every time you take a picture in our partnering restaurants on the app. GiftAMeal is collaborating with food pantries in St. Louis, Detroit and Chicago area to fight hunger. So far more than 35,000 meals have been distributed with the effort of GiftAMeal. You can join us to help the people in need by simply downloading the app and start taking pictures!

Operation food search Volunteering-14.jpg

GiftAMeal is available in both Apple Store and Google Play. To learn more about us, visit GiftAMeal.




Work Cited:

Baker, D., & Keramidas, N. (2013, Oct. & nov.). The Psychology of Hunger. Retrieved May 24, 2017, from http://www.apa.org/monitor/2013/10/hunger.aspx

Facts about hunger in Chicago[PDF]. (n.d.). Chicago: A Just Harvest.

Fuglset, T. S., Endestad, T., Landrø, N. I., & Rø, Ø. (2015). Brain structure alterations associated with weight changes in young females with anorexia nervosa: A case series. Neurocase, 21(2), 169-177. doi:10.1080/13554794.2013.878728

McCormick, L. M., Keel, P. K., Brumm, M. C., Bowers, W., Swayze, V., Andersen, A., & Andreasen, N. (2008). Implications of starvation-induced change in right dorsal anterior cingulate volume in anorexia nervosa. International Journal Of Eating Disorders, 41(7), 602-610. doi:10.1002/eat.20549

Robertson, B. S. (2014, November 05). What is Grey Matter? Retrieved May 30, 2017, from http://www.news-medical.net/health/What-is-Grey-Matter.aspx

Stevens, H. (2017, February 22). When holiday generosity runs dry, food pantry needs are still great. Retrieved June 04, 2017, from http://www.chicagotribune.com/lifestyles/stevens/ct-food-pantry-donations-after-holidays-balancing-0222-20170222-column.html

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