It is a very well known fact that we often eat not because we are hungry, but because of some other reasons. The course of «Understanding Obesity» from Edinburgh University reveals these psychological aspects of appetite.

APPETITE PSYCHOLOGY

When it comes to food, it is not easy to separate psychology and biology of a person.
Practically for any person it is important to get pleasure from eating and it motivates him/her to cook, go to a restaurant or order food on the Internet.

The first and basic function of food is to supply the body with calories, nutrients, minerals and vitamins. The second important aspect is to get satisfaction from taste of products, even when a person is already full. This leads to overeating, to overconsumption of food, in case, suddenly, food will be inaccessible.

EXPERIMENT WITH GEL-LIKE DRINK

In one experiment, Rick Matthes (from Purdue University in the US) provided participants with a newly created drink. One group was told that after getting into the stomach, the drink takes on gel structure and gives a sense of satiety. As proof, this chemical reaction was demonstrated in front of the audience. The second group was not informed about this property of the drink.
In fact, participants in both groups were given a drink without gel. As a result, the participants in the first group found a greater satiety after the drink, they even ate less in subsequent meals.

ATTENTION WHILE FOOD CONSUMPTION

It is known that if a person is distracted while eating, most likely he/she will eat more than usually, as the attention is dissipated, and a person does not follow fullness of the stomach properly. Also, his/her attention is captured by visual information about food or, rather, about its quantity. Therefore, if the brain has recorded that the body is undernourished, then in the next meal a person will try to "catch up" the necessary amount of calories.

But what happens if a person suffers from a short-term memory loss (amnesia)?
A group of people with amnesia were offered meals for a short period of time (but, naturally, they did not remember what they ate an hour ago). It was interesting that they did not refuse to eat not even once — food appearance eclipsed their sense of satiety completely. The participants complained of discomfort in the stomach, but no one said that he/she was hungry. In view of ethical considerations, the experimenters did not allow patients to eat dishes completely.

All this proves that the very picture of a nicely looking product already creates a desire to eat it. So sales of food products in well-designed packages or when the product itself is effectively decorated (if to speak, for example, about cakes) consider this point a lot. Availability of such attractive products often causeses overeating.

PORTION SIZE

Of course, everything depends on the environment of food intake. If this is a restaurant, then a fixed amount of food is served, if home — a person chooses how much to eat. The truth is that recently, in order to attract customers, restaurants have increased the volume of servings: customers were attracted, but there another problem has arisen — people started to get very heavy during the last 30 years.

According to the National Institute of Health, the so-called "breakdown" of portion sizes occurred. 20 years ago, the standard bagel was 7.5 cm in diameter and contained 140 calories, and now it has doubled and contains 350 kcal! This applies not only to bagels: one fast food chain offers a menu of 3,500 kcal. To understand why this is a lot here is some data: for a man weighing 80 kg with a sedentary lifestyle, the daily diet should consist of about 2,100 kcal. Repeated studies prove that a person is inclined to eat more if there is a huge portion of food before him/her, and no matter whether it is a man or a woman.

PORTION SIZE OF PEOPLE WITH BMI> 30

In comparison with a person of a normal weight range, food portions of persons with a high BMI (body mass index) are indeed greater, but if you compare a person with a BMI> 30 and a person with a BMI> 22, the difference in portions is really small. In this case, physical activity or a habit of having frequent snacks plays a significant role.

A PERSON KNOWS IN ADVANCE HOW MUCH HE/SHE WILL EAT

Paradox, but it really so. A survey of a large group of people in the UK showed that in 91% of cases people completely ate the food they were offered, and they were not surprised about that. It turns out that the food that a person is put in front on a plate or that he/she receives is often a "portion" to the last crumb.

What is the choice of serving size?
The answer to this question is the following: food environment (home, restaurant, party), as well as food industry itself can influence a choice. According to statistics, the general amount of food taken by a 21-year-old man, on average, is 23,000 servings. So during life a person learns what kind of food makes him/her feel full and for how long, how nutritious products are, etc.

It is worth paying attention to meal planning. It has several great advantages. Firstly, it saves time. Secondly, the budget, and thirdly — organic waste can be used as a fertilizer, that is, waste is optimized.

WHAT IS BETTER: A MEAL OR SNACK?

As already mentioned, circumstances and environment in which a person consumes food significantly affect the portion amount. Therefore, it matters how food is taken: either a person dines in the appropriate setting with all the attributes, or snacks on the go, in the corner or on the knees.

The scientists from the University of Toronto carried out such an experiment: two groups of people were served the same food, BUT the first group was served it as in a restaurant (serving meals in turns, with a tablecloth, napkins, salt and pepper), and the second got the meal in snack style (a stand, small portions in different order). After a couple of hours, they were re-invited to eat: the participants of the second group ate much more than of the first one.

INCLINATION OF «FOOD UNIT» CONSUMPTION

Although everyone can stop and not eat everything what is on the plate, still there is an interesting phenomenon — a person measures food "units", so it is not so important, whether a sandwich is large or small. This is a sandwich and it is one unit. That is why it is so easy to overdraw with calories, if one does not take into account portion sizes.

I myself notice that the atmosphere of food intake has undoubted influence on me. The more it is refined and comfortable, the more full seems lunch or dinner. But if one can not keep all the "rules" of a meal, he/she always needs to remember about calories content of products so that energy consumption should not prevail its usage.

The pictures are under license CC0.