Currently, one of the greatest challenges facing humanity is obesity, which has acquired epidemic characteristics: it is estimated that 650 million people are affected worldwide. One of the main reasons is that we consume more calories than we need. And a good part of them come from unhealthy foods, which are difficult to resist.
In fact, more and more people base their diet on the pleasure it gives them, and not on physiological necessity. This phenomenon, known as hunger or hedonic appetite, occurs when the delight generated by food exceeds the feeling of satiety, causing a great stimulation of appetite – sometimes compulsive – that alters our eating behaviors. Furthermore, it is known that foods rich in fats and sugars enhance this mechanism.
Hunger is defined as the craving or urgent need to eat. However, the regulation of appetite and eating behavior is a very complex process where two types of factors interact: internal, controlled by hormonal and molecular signals from the intestine, adipose tissue or the brain-intestine axis; and external, based mainly on the learning produced by the signals generated when ingesting food.
In this second case, emotional, cultural and social elements intervene as well as the pure search for pleasure. We feel a subjective joy when eating: we enjoy the presentation of a dish, an aroma or a texture. We even like the colors we see or the sounds produced by eating them. Sensory perceptions will reinforce that pleasure, increasing the probability of repeating it.
The sense of sight participates directly in this mechanism. It is known that looking at a meal or its photograph is enough to initiate the physiological process of eating: it increases salivation, activates the secretion of gastric acid, bile and digestive enzymes and even promotes the release of hormones such as insulin, cholecystokinin or ghrelin in the blood But above all, it unleashes the desire to put the delicacy in your mouth.
In short, what we perceive through our eyes, even if it is only its representation, directly influences our eating behavior. In fact, a recent meta-analysis concluded that exposure to visual food cues has the same effects as real food or olfactory stimuli.
Along these lines, several studies have shown how perceiving images of food – including shape, color, portion size and presentation – activates the brain areas involved in taste perception and reward processing, directly affecting food regulation. of appetite and satiety.
The Internet, and especially social networks, constantly put before our eyes images of very appetizing dishes with an impeccable appearance. And this, coupled with the current ease of access to food, could be exacerbating the obesity problems we face.
But this bombardment could also become an ally in controlling eating behavior, as Tjark Andersen and his collaborators have shown. Some authors have even preliminarily suggested that consumption of food pictures increases satiety. How is this possible?
Think of a food that you really want, find pictures of it on the internet, and while looking at them, imagine that you are eating it. This will trick the brain into stimulating the same areas that would be activated by, say, a real candy bar.
These are the conclusions of a recent study, according to which seeing repeated images (about thirty times) and imagining food increases satiety and reduces the desire to be consumed when compared to the experience of participants who viewed the photo only three times . Previous experiments pointed in the same direction.
In short, and waiting for new studies to confirm it, we could be faced with a new dietary strategy with a long-term positive impact on weight control and eating behaviors. Then, the expression "eating with the eyes" would stop being a simple metaphor.
This article was originally published on The Conversation.
