Does Food Addiction Contribute to Global Obesity?
Right now, scientists are actively debating whether highly processed foods are addictive and whether it contributes to our continued failure to reduce obesity and diet-related illnesses around the world. Two experts share their views on different sides of the debate: Dr Ashley Gearhardt argues that these foods are addictive, while Dr Johannes Hebebrand argues that “food addiction” is not responsible for obesity rates.
Highly processed foods are addictive
Dr Ashley Gearhardt: In our society, it is widely believed that excessive consumption of highly processed foods, such as chocolate, pizza, and pastries, contributes to excessive weight gain and poor health. Millions of people try to reduce their consumption of highly processed foods each year, but few find long-term, sustainable success. People do not change their diet even when faced with serious negative health consequences, such as amputations, blindness and premature death. As highly processed foods spread around the world, we are seeing obesity and disease rates rise with them.
What about highly processed foods that pose such a threat to public health? Why are people unable to quit smoking even though they are highly motivated to do so? A growing body of evidence shows that highly processed foods are able to trigger addictive processes similar to addictive drugs like tobacco. Our brains are designed to find rewarding high calorie foods to make sure we survive times of starvation. Carbohydrates (like sugar) and fat are high in calories and trigger the release of feel-good chemicals in the brain. For much of the history of mankind, the best shot of sugar we could hope for was to find fruit. The fat would come from hunting for an animal or hunting for nuts. While our brains are still in the Stone Age, the food industry has become adept at increasing carbohydrates and fats to unprecedented levels and combining them with dozens of additives to create unusually rewarding foods. These highly processed foods trigger reward responses in the brain that far exceed levels associated with natural foods.
Addictive drugs and highly processed foods are created using very similar processes. For example, humans refine and process a natural substance (like a tobacco leaf) and turn it into a product (like cigarettes) that contains abnormally high levels of a rewarding substance (like nicotine), then add dozens additives (like ammonia and menthol) to further improve it. These addictive drugs hijack the same brain reward centers that are so powerfully activated by highly processed foods. In fact, highly processed foods and addictive drugs are often consumed for the same reason: to experience a sense of pleasure and to reduce negative emotions. Whether it is a highly processed food or a drug, a substance can become so rewarding that it can trigger compulsive behavior (that is, the person cannot even stop if she really wants to). This is good news for the industries that profit from the sale of these substances, but bad news for the rest of us.
Highly processed foods are not addictive
Dr Johannes Hebebrand: The food industry thrives on the sale of its products. In an effort to increase sales, thousands of new food products are marketed each year. Food has to be tasty and somehow has to fill a market niche. A large enough number of people must be attracted to a specific food so that it stays on the shelves of a supermarket. Obviously, a cheap price guarantees a potentially large market. Food industry operations depend on cultural, social, economic, legal, regulatory and political factors.
Should we use the term food addiction to explain overeating and obesity? Most obese people would certainly not consider themselves to be food addicts. Only a sub-group would respond in the affirmative. Yes, they do suffer from “grazing,” cravings and binge eating attacks, and cannot stop eating despite negative health implications and negative social consequences. They may report eating behavior suggesting tolerance and experience withdrawal symptoms.
But what exactly are they addicted to? There is no clear evidence for one or more substances in foods that elicit a reward comparable to that obtained from consuming legal or illegal drugs. Try a limited amount of any medication, say you inhale cigarette smoke deeply or drink half a glass of wine. You will quickly experience an alteration in the way you see yourself and your surroundings. This rapid onset, which so gratifying may represent the initial first step in the development of an addiction, does not occur with the ingestion of food. People who see themselves as food addicts will resort to many foods. They will not become addicted to just one food.
Why then do some people declare that they are addicted to food? Obese people need more food than others to maintain their body weight. They find it difficult to maintain a reduced body weight, which can be experienced as “food addiction”. Other people will feel a strong urge to overeat when under stress, anxiety, or depression. Obesity is generally present in families with genetic factors responsible for the family burden. In conclusion, the urge or urge to overeat can subjectively be perceived as food addiction, but in reality depends on a range of genetic, physiological, social and psychological reasons and not on the use of a particular substance.
The verdict? More research is needed
Food industry practices contribute to overeating and obesity; however, disagreement persists as to whether highly processed foods meet the criteria to be considered addictive. Future research will help inform this debate and guide next steps on the best ways to promote healthy eating.
Featured Image By RitaE via Pixabay