ISLAMABAD: A recent study suggests that sensations of hunger and fullness may be associated with individual expectations and perceptions about the meal, and not with how much food is on the plate.
Several new studies have explored the link between the mind, perception, and various aspects of health. Medical News Today have, for example, covered research that tied physical fitness to the perception of one's own activity levels and a study suggesting that feelings of pain may often have more to do with the mind than the body.
A new study led by Dr. Steven Brown, of Sheffield Hallam University in the United Kingdom, now explores the way in which the mind may influence our states of hunger and fullness.
The findings were presented earlier this week at the British Psychological Society's Division of Health Psychology annual conference, held in Cardiff, U.K.
Previous research had already looked at the relationship between what we think about what we eat and how much of that food we are likely to consume.
For instance, an existing study led by Dr. Brown and team suggested that "expected satiety" - that is, how full you expect to be after a meal - plays a significant role in how full you will actually feel.
Now, Dr. Brown and team have used solid food to see if they can replicate previous findings.
In the current study, Dr. Brown also investigates whether or not levels of the "hunger hormone" ghrelin, which helps to regulate our sensation of hunger, play a role in this equation.
He told us that taking blood samples from the participants allowed him and his team to "investigate whether any differences were related to participants' ghrelin response," making this "a far more comprehensive investigation."
Twenty-six individuals participated in the study. On two different occasions, participants were served breakfast, and their feelings of hunger and satiety, as well as their behavior at the subsequent meals, were monitored throughout the day.
On the first occasion, the participants were told that they were eating a two-egg omelette, whereas on the second visit they were told that it was a four-egg omelette. However, both times they were served omelettes containing three eggs.
What the researchers found was that when people thought they had eaten a smaller breakfast, they reported feeling hungry after only 2 hours. They also ate more for lunch and had a larger calorie intake throughout the day than when they thought they'd had a larger breakfast.
"We were able to measure participants' consumption throughout the rest of the day and found that total intake was lower when participants believed that they had eaten a larger breakfast," explains Dr. Brown.
The researchers also collected blood samples from the participants on the two occasions they worked with them. Dr. Brown and team were interested in analyzing the participants' ghrelin levels, and learning whether they had an important role to play in their sensations of hunger and satiety on those occasions.
"Having analysed [participants'] levels of ghrelin, a known hunger hormone, our data also suggest that changes in reported hunger and the differences in later consumption are not due to a differences in participants' physical response to the food," Dr. Brown notes.
He suggests that this finding shows how the subjects' perceptions of the meal before consumption significantly influenced their subsequent state of hunger, as well as their food intake.
Dr. Brown told that significant differences in the sensation of hunger were typically recorded 2 hours after the meal. However, he was surprised to find that even when no significant shift in the sensation of hunger was reported, the participants still consumed larger lunches if they recalled having a smaller breakfast.