Being obese and overweight has already been linked to several health problems. Now, researchers from the University of Cambridge conducted a small study that adds weight to the existing ones linking it to poor memory.
The researchers from the Department of Psychology at the university found a link between poorer performance on a test for episodic memory and a high body mass index in the subjects. BMI is what normally nutritionists and doctors use as a basis to determine whether a person is underweight, normal, overweight or obese.
People who are heavy for their own height mostly score higher in the BMI chart. The World Health Organization has several classifications for different ranges in BMI.
Those who score less than 18.5 are classified as underweight. People who score between 18.5 and 24.9 are considered normal weight.
Class I obesity starts at a BMI score of 30.0 up to 34.9. Class II obesity starts at 35.0 up to 39.9. Those who have a BMI score of more than or equal to 40.0 are classified class III obesity.
There have been existing researches regarding how overweight people develop more problems with their cognitive abilities. Obesity has already been linked with the dysfunction of the hippocampus in the human brain.
Hippocampus is responsible for learning and memory tasks such as reading a new sentence and memorizing it. Obese people are also known to have a dysfunctional frontal lobe, which is responsible for a person’s emotions, problem solving and decision making.
Studies linking obesity to poorer memory are limited. The new one from the researchers at the University of Cambridge will immensely help for future scientists and doctors that may want to look at what happens to an obese person’s cognitive abilities.
In the United Kingdom alone, about 60 percent of adults are either overweight or obese based on their BMI scores. Experts predict that the percentage can still increase up to 70 percent by 2034.
The other health problems that one can get from being obese or overweight include higher risks for heart attacks and diabetes. Obese people who have a sedentary lifestyle would also most likely develop problems in the joints and bones as they subject theirs with extra weight, pressure and stress.
In addition, obese or overweight people are also prone in developing psychological problems later on such as anxiety and depression. It’s no surprise that society prefers good-looking thin male and female models over fat and fluffy average joes.
Dr Lucy Cheke said in a press release: “Understanding what drives our consumption and how we instinctively regulate our eating behaviour is becoming more and more important given the rise of obesity in society. We know that to some extent hunger and satiety are driven by the balance of hormones in our bodies and brains, but psychological factors also play an important role – we tend to eat more when distracted by television or working, and perhaps to ‘comfort eat’ when we are sad, for example.”
The researchers also said that episodic memory could help overweight people to control their eating. Dr Cheke added that a person could remember what they had for lunch and it could influence the hunger they currently feel. If they remember that they already ate a heavy lunch meal, there is a chance that they would not eat so much anymore at dinner time.
However, the study found out that people with high BMI had poor episodic memory. It means that being fat will sabotage a mechanism in their brain that could possibly help them to lose weight.
For their study, the researchers gathered 50 test subjects that were aged between 18 and 35. The lowest BMI in the test subjects was 18 while the highest was a staggering 51.
The participants were asked to play a short memory test called the “Treasure Hunt Task” where a person would be tasked to mentally hide items around a visually complex scene. For instance, a participant could be asked to hide their smartphone somewhere in a factory with seven huge rooms and heavy equipment.
Participants who played the memory test were given two “days” inside the test. After choosing where to hide the items, the researchers asked which items were hidden, when they hid the items and the location in the fictional setting where they hid them.
Those participants who had a higher BMI, most likely the ones who are at the overweight level, had performed poorly compared to those who were at a normal weight. The researchers said that the results of their study suggest that those with higher BMI have reduced abilities in retrieving episodic memories.
Still, the researchers believe that further studies should be conducted to reach a general consensus. They need more data to crunch in order to generalize whether overweight individuals do actually perform worse in episodic memory tasks in everyday life.
Dr Cheke said: “We’re not saying that overweight people are necessarily more forgetful. but if these results are generalizable to memory in everyday life, then it could be that overweight people are less able to vividly relive details of past events – such as their past meals. Research on the role of memory in eating suggests that this might impair their ability to use memory to help regulate consumption.”
Even if the future studies provide conclusions that episodic memory is not affected by being overweight, people should still strive to be on the healthy side of life. Eating less might not be enough as there are still other factors to consider such as calorie count and macro nutrition.
Dr Jon Simons, the co-author in the study, said that they could be able to create interventions that will help obese people. More studies will also help them to address the psychological factors.
The study, which was published in The Quarterly Journal of Experimental Psychology, was made possible due to funding from the James S McDonnell Foundation, the Medical Research Council and Girton College and the University of Cambridge.