The Grapevine

Feeling Hangry? Eating Poorly Affects Your Mood, Study Shows

People who claim to get irritable and moody when they haven't eaten are not imagining it after all. By studying the behavior of rats, researchers from Canada were able to find evidence to explain why people feel "hangry" i.e. hungry and angry. 

The study titled "An exploration of the aversive properties of 2-deoxy-D-glucose in rats" was recently published in the journal Psychopharmacology.

"We found evidence that a change in glucose level can have a lasting effect on mood," said Francesco Leri, a professor in the Department of Psychology at the University of Guelph. "I was skeptical when people would tell me that they get grouchy if they don't eat, but now I believe it. Hypoglycemia is a strong physiological and psychological stressor."

Hypoglycemia i.e. low blood sugar was induced in rats by injecting them with a glucose metabolism blocker. After the glucose drop kicked in, these rats were placed in a specific chamber. On another occasion, the rats were injected with plain water and placed in a different chamber.

Later, when the rats were given the choice to enter either chamber, they ended up avoiding the one where they experienced hypoglycemia. Leri notes that such "avoidance behavior" is a strong sign that the animal is experiencing stress and anxiety.

Apart from observing their behavior, the research team also tested the blood samples of the rats. When given the glucose metabolism blocker, the rats were found to have higher levels of corticosterone which suggests physiological stress.

Thomas Horman, a Ph.D. student who led the study, stated this connection between poor eating and changes in mood could help determine how depression is linked to conditions such as obesity, diabetes, bulimia, and anorexia.

"The factors that lead someone to develop depression and anxiety can be different from one person to the next. Knowing that nutrition is a factor, we can include eating habits into possible treatment," he said.

Feeling a little "hangry" or moody due to missing a meal or facing a delay in acquiring a meal is still only a short-term effect. Further research should seek to understand whether poor eating in the long run could actually raise the risk of mood disorders. If a link is established, chronic hypoglycemia may be considered a strong risk factor for developing depression and related behaviors.

"Poor mood and poor eating can become a vicious cycle in that if a person isn't eating properly, they can experience a drop in mood, and this drop in mood can make them not want to eat," Horman explained. "If someone is constantly missing meals and constantly experiencing this stressor, the response could affect their emotional state on a more constant level."