Why screens make you fat


The links between screens and overweight or obesity are now clearly demonstrated by scientific research in both children and adults.

Marie-Pierre Fourquet-Courbet and Didier Courbet, authors of this article, are professors in Communication Sciences at Aix-Marseille University (AMU). The original version of this article has been published on The Conversation website, of which franceinfo is a partner.

Smartphone, television, tablet, game consoles, social networks, Internet … The screens have invaded our lives. This is a problem because the links between their use and overweight or obesity are now clearly demonstrated by scientific research in both children and adults.

Today, nearly one in two French people is overweight or obese, which is a major concern in terms of public health, because this state promotes in particular the development of diabetes, cancer or cardiovascular problems, pathologies that are causing thousands of premature deaths each year. In addition, obesity is associated with anxio-depressive disorders, and therefore a certain malaise in everyday life. Economically, its cost is considerable: about 20 billion euros per year.

This problem is even more marked as the time spent watching screens continues to increase, especially among young people, and has become the first human activity, outside sleep. How do the links between screens and weight gain work? Four mechanisms have been highlighted.

The more children and teenagers watch screens, the more they consume products of poor nutritional quality (sweets, cakes, fast food, sugary drinks, salty snacks …) and this, without necessarily being hungry. Result: the energy intake they store is too high. Moreover, the young people concerned consume insufficient quantities of fruits and vegetables. It is indeed an influence of screens, since when children and teenagers are asked to use them less, the number of calories they eat decreases, as does their overweight.

In addition, adults eating or dining in front of a screen are numerous, smartphone or television in mind. Our attention, captivated by images and sounds, is no longer directed to our sensations related to the act of eating. Satiety, which should normally stop us from eating when it occurs, is no longer perceived. Consequence: the quantities ingested increase on average by 25%! One solution to remedy this situation would be to focus better on the act of eating. To indulge in it slowly, in full consciousness, in the conviviality and without screen.

The screens are used most often in sitting and static position, undeniably increasing the sedentary lifestyle. Admittedly, energy expenditure differs according to the content and the activities carried out. For example, watching television consumes less energy than playing video games. But anyway, a vicious circle sets in. The more we look at the screens, the more we are sedentary, the more we gain weight, the more difficult it is to move and the more we stay in front of our screens …

Does increasing screen time decrease physical activity time, especially for children and teens? The question is not completely settled. While there is a negative correlation between exposure to screens and the practice of moderate or high physical activity, the causal link is not yet clearly established. Researchers asked young people to lower their screen time: they found only a small increase in their physical activity. However, further research is needed to better ascertain the cause-and-effect link.

Let's not forget that physical inactivity must be distinguished from physical activity. You can do a lot of physical activity, for example on weekends, and be sedentary the rest of the time. For his health, it is therefore recommended to act on both. First, get up and walk at least a few minutes after spending two hours sitting. Second, practice at least 30 minutes of dynamic physical activity a day. Walking quickly, for example, is perfect.

Advertising for junk food

On children and adolescents, food advertising is truly "effective": it causes better evaluations of publicized brands, which would then be preferred to others. It also affects actual eating behaviors for these brands. However, many advertisements concern foods and drinks of poor nutritional quality.

Moreover, it would appear that an advertisement for the products of a particular brand will also increase the demand for the entire food or beverage category concerned. For example, an advertisement for a candy brand would sell more candies, all brands combined. The problem has grown in recent years on two levels.

Firstly, there is an intensive development of the digital means of communication to which children and adolescents are particularly exposed: advertisements on the Internet, on mobiles (such as free music platforms online) and on social networks, video games advertising specifically manufactured by the brands (advergames), insertion of brands within a video game that young people usually play (advertising called "in-game", for example in the famous football simulation Fifa) … Recent scientific works show that teenagers and young people Adults are more influenced by digital marketing techniques than by those of more traditional marketing.

Secondly, there are increasingly frequent uses of commercial persuasion techniques that affect consumers at a low or unconscious level, more specifically about memory and so-called "implicit" attitudes. For example, banner ads on the Internet have a positive effect on the brand's attitude without being consciously seen on the screen. The digital message of a brand barely glimpsed and soon forgotten leaves marks favorable to the brand, which remains present in implicit memory at least three months after exposure. The development of neuromarketing aims to increase this type of impact, located below the threshold of consciousness.

Neuromarketing is the use of neuroscience and cognitive science by brands to improve their marketing and communication strategies. These persuasive practices that are used to sell further reduce the freedom of consumers to the extent that they relate to food and beverages. Indeed, the latter affect the biological needs of the human being that it is easy to "manipulate", almost subliminally, without being aware of it, particularly by evaluative conditioning techniques.

Many food advertisements are aimed at generating positive emotions in children, as in the older ones, to disrupt the process of rational product choice for the brand. Such advertisements "artificially" surround the mark of an unreal emotional imaginary, symbols of "freedom" or social success that are no longer related to the functional characteristics of the product. This is for example the case of the association of the brand with characters, fictional or real as celebrities (sportsmen touting a brand of drinks or chocolate bars) or fun mascots (tiger, lion … on packages of cereals for breakfast).

These problems do not only concern the youngest, but also the adults. One solution would be to regulate all types of advertising for food products, by making it mandatory to display NutriScore, this five-color nutritional logo informing consumers about the nutritional quality of foods, ranked from A to E. French could probably make better choices in their purchases. It would also encourage agri-food industries to produce less fat, less salty and less sweet products. If members have recently voted in favor of such a law, the ball is now in the senators' court, which, it is hoped, will have to be ratified.

Hyperconnected people would lose sleep time, nearly 2 hours per night. Their sleep would also be of lower quality and they would suffer more insomnia. Two factors would come into play.

In the first place, the presence of blue light emitted by light-emitting diodes (LEDs) of the screens closely watched is interpreted by the brain as daylight. It keeps him awake and decreases the secretion of melatonin, a sleep hormone. The moment of falling asleep is delayed. Secondly, the excitement provoked by the videos or the messages consulted in the evening also hurts sleep. For example, when people, teenagers or adults, are very emotionally invested in social media, they sometimes feel upset when they are disconnected. They have trouble relaxing at bedtime, victims of FOMO (fear of missing out), this fear of missing a new message or interesting content.

Poorly or insufficiently sleeping increases the risk of being overweight, in addition to causing other problems, for example related to the poor concentration and memorization of the day. The sleep time is precious. It is therefore best to disconnect screens one to two hours before bed. Ultimately, for children, teenagers and even adults, a good rule to acquire at the earliest: no mobile connected, no screen in the room!

In a more general way, it may be good to re-read the advice on the proper use of screens, especially as regards the education of the youngest. And to devote more time to off-screen activities.The Conversation

Didier Courbet, Professor of Universities and Researcher in Communication Sciences, Aix-Marseille University (AMU) and Marie-Pierre Fourquet-Courbet, Professor of Universities in Communication Sciences, Aix-Marseille University (AMU)

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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