To treat a eating disorder, we need to know what emotion feeds him

Identifying how different emotional states and neural pathways influence our eating behaviors could pave the way for better ways to combat eating disorders and obesity.

Eating disorders such as anorexia and bulimia can have deadly consequences. They affect around 20 million people in the European Union, at an estimated cost of 1 trillion euros per year. The exact cause of a eating disorder varies from one person to another and is influenced by factors such as biology, psychology and the environment.

People with eating disorders often adopt unhealthy behaviors, such as dieting, starving, gorging and purging themselves to cope with overwhelming emotions and stressful situations. .

Although the idea of ​​emotionally eating or stress is widely known, it is surprisingly complex, says Professor Jens Blechert, a psychologist specializing in health and health sciences, at the University of Salzburg in Austria . "There is a relationship between stress and nutrition, but it can change orientation for different people," he said.

As part of a project called NewEat, Professor Blechert is studying how psychological factors known to interfere with food lead to unhealthy patterns and behaviors. His team works with people in good health. suffer from eating disorders, such as anorexia, bulimia, binge eating disorder; or who are obese. They hope to improve the treatment of eating disorders and fight against overeating in the general population.

According to Professor Blechart, they found that the type and degree of emotion felt by an individual affected dietary habits. "The type of emotion that is at the center of the experience matters a lot," he said.

For example, emotions such as anger and anxiety make most people eat less, while sadness, depression and disappointment make them eat more, he explains. The response to emotions becomes even more complex for people with eating disorders, but the basic pattern remains the same. For example, a bulimic and sadistic person will probably eat more, but more intensely, while an anorexic person in the same emotional state may react by not eating and demonstrating greater restraint.

Food behaviors

To carry out their research, the team developed a smartphone app that, over two weeks, poses multiple questions to its users – in good health and to people with eating disorders older than 16. at age 50 – to create emotional consumption patterns. Based on personal history, eating habits and daily emotional states, researchers will know when some people may be at risk of binge eating and developing a eating disorder.

The team discovered three main mechanisms for determining eating behaviors. The first is the physiological or stress response that puts the body into alarm mode and reduces appetite. Secondly, there is the psychological response of self-reward or self-appeasement that increases appetite.

"We have two mechanisms that oppose each other – the strength of each of these mechanisms is different," said Professor Blechert. "For example, some people do not have this strong psychological need for self-reward, and for them the physiological response is overwhelming, so they lose appetite and lose weight."

The third mechanism is the diet style, which can be characterized by frequency and intensity level. For example, people with anorexia have a very strict diet, while those with binge eating lack of means of restraint.

"Once we know the emotional meal style and the diet style of a person, we can predict with enough precision when a food disorder crisis or binge eating will occur," he said. said Professor Blechert.

The team is currently developing its application for a personalized intervention as part of a project called SmartEater, which will be tested this summer on post-treatment bulimic patients. "People (with eating disorders) could benefit from an application or Internet program that would work in an individualized way and help them identify triggers, prevent situations, and so on. ", said Professor Blechert.

The idea is to be able to intervene at the right time, when stress and emotions are strong, he says. The application could predict food bulimia attacks – for users who have a eating disorder or are healthy people who eat too well – and send notifications to warn them not to eat, for example.

interventions

The widely accessible interventions are rare, according to neuroscientist Professor Suzanne Dickson of the University of Gothenburg in Sweden. "We do not really have good interventional treatments for eating disorders that are effective for the majority," she said.

Professor Dickson is trying to better understand the brain pathways that influence our dietary choices and behavior in order to enable the development of new drugs, including more personalized ones, for people with eating disorders and diabetes. ;obesity.

"When we eat, the reward system of the brain is activated," she said. This part of the brain is involved in a "hedonic diet" – when you eat too much and make poor food choices – but also incorporates other systems, such as stress, that predispose people to overeating and to making unhealthy choices, she says.

Professor Dickson coordinated a completed project called NeuroFAST, which explored the neurobiology of food consumption, addiction and stress – what happens biologically in the brain and how cells eventually form functional neural circuits responsible for these behaviors. .

She says that we often hear about addictive foods in the context of the obesity epidemic, but that the problem lies in people's behavior, an addiction to eating rather than "eating." to the food itself.

"Although people who eat too much know that they are harming their health, they continue to do so.This presents all the symptoms of addictive behavior, such as gambling," said the Professor Dickson.

She and her team discovered that intestinal hormones are involved in our eating behaviors. In particular, the appetite-regulating hormone called ghrelin is released into the blood when we are hungry and acts on the brain's reward system, which increases our motivation to eat, especially for tasty foods .

"Our data shows that when ghrelin levels are high, we are more likely to choose healthy foods – food choices that are related to survival," said Professor Dickson. "When we are hungry, ghrelin uses the reward system to help us find the motivation to find food."

Reward system

The dopamine signal, in the way of the reward system, is a key factor that motivates us to eat, but there are many others to consider before we can fully understand what makes us decide what, when and how much to eat, says Professor Dickson.

In order for the dopaminergic reward system to remain activated, it is important to continually introduce new foods – only eating your favorite food all the time will no longer give you the desired boost, the pleasure of dopamine.

"It's the way to help us get a variety of nutrients into our environment," said Professor Dickson. "If our reward system was activated only by one food, from an evolutionary point of view, that would obviously not be good for our nutrition."

She now hopes to find out which pathways in the brain control overeating behaviors, as well as the hormones and environmental cues to which these behaviors respond.

"Obesity could be a hundred diseases that make people eat too much, so we need to determine what the common pathways are, but also how they differ from one person to the other," he says. said Professor Dickson.

The three most common eating disorders:

Eating disorders are considered mental illnesses and can take many forms. They tend to reach more women than men, usually in adolescence or early adulthood, but may develop earlier and later.

Of any mental illness, anorexia nervosa has the highest mortality rate. People with anorexia are at high risk of starvation, suicide or organ failure. Symptoms usually include extreme dietary restriction, fear of gaining weight, and a distorted self-image. Anorexic patients usually force themselves to vomit, use laxatives, or exercise excessively to lose weight.

People with bulimia nervosa go through episodes of uncontrollable and excessive eating. These overeating crises are followed by purges, fasting, forced vomiting, laxatives and diuretics, or extreme exercises.

Binge eating is one of the most recent disorders but it is also relatively common. People with this disorder lose control of their diet and can eat quickly and in excess over a period of a few hours. They usually do it in private and even when they are not hungry. These episodes are often followed by remorse and guilt, but they are not purged later. Bulimia binge eating is badociated with obesity.