In fact, when we eat we are not just nurturing ourselves, we also experience different emotions. We feel pleasure when we like food but we also feel guilty when we break our diet. In addition, our mood influences not only the amount of food but also the choice.
Therefore, to follow a healthy diet, it is essential to understand the psychological mechanisms that hide behind nutrition.
1. You don’t know when you’re really full
We believe the amount of food we eat corresponds to the hunger that we’re experiencing. But the appetite is actually just one factor in the equation. The amount of food that we can eat also depends on the size of the dishes and even the light and colors of the room.
In a very interesting study conducted at Cornell University, researchers used a soup bowl filled automatically through a hidden mechanism. People who used that bowl ate almost twice as soup, but didn’t feel more satiated than those who ate a normal plate.
This indicates that the connection between the stomach and the brain works slowly, the satiety signal takes half an hour to be processed by our mind. Therefore, the feeling of satiety is closely linked to the quantities we see, rather than what we actually eat.
2. You like more or less the food depending on the moment of the day
We tend to think that food have intrinsic flavor we may like more or less. However, it’s not true, a simple experiment shows that the perception of flavors not only changes throughout life but also during the same day.
In fact, whether you like carrot with vegetables and meat for dinner, you won’t probably eat them at six in the morning, for breakfast. And even the context in which the food is presented influences its taste.
Throughout the years we have associated certain foods to certain moments, so that when we meet them at unusual hours we oppose some resistance and may even reject a taste we usually appreciate.
3. Trying to suppress thoughts about food leads to bingeing
It may seem a contradiction but it has shown that trying to suppress certain thoughts has a rebound effect. In fact, when we try to remove a thought from our minds, this develop a hyper-vigilant attitude causing the opposite effect: the idea becomes even more recurrent.
The same goes for food. In an experiment conducted at the University of Florida, the researchers analyzed the eating habits of overweight people and their everyday thoughts. So they could see that people who were most likely to give in to cravings and binge eating were precisely those trying to suppress thoughts about food.
Today we know that weight loss diets that are too restrictive generate an emotional loss of control. These people, once they leave the diet regime, not only recovered the lost kilos but even earn a third more.
4. A bad mood makes you choose unhealthy foods
The concept of “emotional hunger” is old. In fact, many people don’t eat because they feel hungry but simply because they feel anxious. Therefore, the emotional factor is essential in any weight loss program.
However, it has also been appreciated that when we get angry, we tend to choose foods that otherwise we wouldn’t eat. In fact, when we feel angry, stressed or depressed, we usually choose sugary snacks and foods with a high fat content.
The main problem is that, when we are angry, we aren’t able to exercise self-control, which is a limited resource, and are more likely to yield to temptation. In addition, this type of food generates a very strong response in the brain, which activates the pleasure centers. Therefore it becomes a kind of natural compensation.
5. The product labels determine how much you will like the product
The perception of taste varies depending on many factors, many of them psychological. For example, it has been found that when people are presented with the same wine but with different labels, they prefer one that has been “socially” labeled as better, but as a matter of fact both wines are equal.
A particularly interesting experiment conducted at the University of Sussex irrefutably proves this fact. The researchers told the participants that were assessing the taste of a new food and the acceptance it would have on the market. Some were told it was an ice cream flavored with smoked salmon, others that it was a frozen salty mousse. Although it was the same product, the persons who were told it was an ice cream rejected it, those who were told it was a mousse loved it.
This demonstrates that the expectations we have on products, generated in part by the labels, food critics and even by people around us, influence the acceptance or rejection of certain flavors.
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Yeomans, M. R. et. Al. (2008) The role of expectancy in sensory and hedonic evaluation: The case of smoked salmon ice-cream. Food Quality and Preference; 19(6): 565–573.
Wansink, B. et. Al. (2007) Fine as North Dakota wine: Sensory expectations and the intake of companion foods. Physiology & Behavior; 90(5): 712-716.
Wansink, B. et. Al. (2005) Bottomless bowls: why visual cues of portion size may influence intake. Obesity Research; 13(1): 93-100.