We are in the midst of a serious health crisis. The World Health Organization (WHO) speaks of an epidemic of non-communicable diseases. In fact, noncommunicable diseases (NCDs) are responsible for a total of 74% of global deaths: 41 million people die from an NCD every year. Cardiovascular diseases are responsible for most deaths, followed by cancers, chronic respiratory diseases, and diabetes¹.

There is consensus on the risk factors of NCDs: tobacco and alcohol abuse, as well as physical inactivity and an unhealthy diet, increase the risk of dying from an NCD1. In addition, unhealthy diet and lack of exercise can result in elevated blood pressure, elevated blood glucose, elevated blood lipids, and obesity. These factors are referred to as metabolic risk factors and may in turn lead to cardiovascular disease¹.

Therefore, in addition to reducing tobacco and alcohol consumption (see SDG 3 Target 3.5), an active lifestyle and healthy diet are essential to prevent NCDs^{3, 4, 5, 6}. A detailed review of risk factors for the most common NCDs confirms this: the strongest protective factors were healthy diet and physical activity. For example, adherence to a Mediterranean diet resulted in up to 36% risk reduction for all five NCDs⁷.

Nevertheless, according to the current nutrition report, 41% of the Austrian population is overweight or obese⁸. The International Diabetes Federation⁹ projects a 46% increase in global diabetes rates by 2045, and the World Obesity Federation¹⁰ reports that the prevalence of obesity is increasing worldwide. The 2021 Global Nutrition Report¹¹ highlights severe nutritional deficiencies, which have not improved over the past decade. For example, fruit and vegetable intake is still about 50% below the recommended five servings per day. In contrast, the consumption of sugary drinks, which is strongly discouraged, is steadily increasing¹¹.

For the most part, there is scientific consensus on what a healthy diet should roughly look like⁴. It can be assumed that in higher-income countries there are mostly sufficient resources available to opt for the recommended diet. However, there is obviously an extreme discrepancy between current research knowledge and actual individual behavior.

At the same time, nutrition and diet tips are piling up on the web. The global market for weight loss products and services was estimated at over 250 billion dollars in 2021¹². Recommendations range from "don't eat too much sugary food“¹³ to "there's real fat-killing power in grapefruits“¹⁴. This suggests healthy eating is a personal choice and, as a corollary, the individual is responsible for his or her health or, in the case of obesity, chronic disease. Crawfordt¹⁵ was quick to criticize that for many diseases, the individual's risky behavior is seen as the cause of the problem and a lifestyle change by the individual is seen as its solution.

To hold a person completely responsible for his or her eating behavior assumes that people proceed purely rationally and make decisions whose reasons they can explicitly state. However, it is now recognized that food choice decision making is a complicated process: an interplay between internal (e.g., interoceptive hunger signals, dietary self-control) and external factors (e.g., family eating habits, food marketing)^{16, 17, 18, 19}. In fact, eating behavior is strongly based on habits, as people strive to minimize the cognitive resources expended in decision-making processes^{16, 20}. To develop effective interventions and prevention programs, we need to understand and address the emergence of health-risk patterns in dietary decisions.

Fundamentally, the physiological need for food causes humans to eat. Evolutionarily, this ensures that energy is consumed as soon as it is available and thus can be stored for times of food scarcity²¹. However, food in modern societies is characterized by availability, affordability, taste, and successful marketing¹⁹. Or, as Klotter and Endres put it, we live in a "land of milk and honey" (p. 1)²². This becomes a problem in that the rewarding properties of food can override basic satiety signals. Leng et al.¹⁹ explain that when certain foods are ingested, there is a sudden surge of dopamine in the brain's reward system. This process, which has a strong reinforcing effect, is common to palatable foods and drugs²¹.

In order to reduce the cognitive resources used in decision-making situations, people also resort to a number of heuristics. Consumers often find it difficult to process all the available information to evaluate the healthfulness of foods. Therefore, they rely heavily on sensory stimuli (e.g., the association blue/green = healthy in relation to packaging color) or on their intuition²³. Here, however, they usually make a number of systematic errors. For example, it is well known that labels such as "organic" or "low cholesterol and fat" carry a strong halo effect^{16, 24}, causing consumers to believe that these foods are more health^{24, 25}. Another misconception is that expensive foods are automatically healthier^{23, 26}. Thus, in our everyday consumption, we are anything but rational actors. Not only do we use evidence-based information, but we are influenced by a broader information environment shaped by cultural factors, advertising, and other media.

Children are particularly vulnerable to the negative effects of food advertising, which is known to promote hedonistic, taste-oriented, and unhealthy food choices¹⁷. However, it is essential that children learn to make healthy eating choices because once established eating habits tend to be stable. Several studies (for a review, see Nicklaus & Remy, 2013²⁷) have shown that food preferences developed early have a long-lasting influence. This effect is evident, for example, in newborns: if they are exposed to a range of vegetables at an early age, their subsequent intake of and preference for vegetables increases²⁸. According to Köster¹⁸ , many learning processes related to food preferences take place unconsciously. Especially at a young age, children are strongly influenced by the praise and approval of their parents. Somewhat later, the eating behavior of adolescents is shaped by imitation learning of their environment¹⁸. Here, parents or the family environment have a particularly influential role model function^{16, 29}. According to Köster¹⁸ , it is precisely these unconscious eating habits learned in childhood that are particularly resistant to change, which is why it makes sense to invest in healthy eating programs at an early age. However, the family is not only relevant as a social learning environment. Based on twin studies, it is estimated that BMI is approximately 77% heritable³⁰. The cognitive component of decision making is then added, especially in adulthood18. Thus, the family system or social environment plays an active role in developing and promoting behaviors that will permanently shape a person's eating habits.

The above factors should give an approximate idea of the complexity and multi-faceted nature of eating habits. Of course, many other components also play an essential role in this process (e.g., socioeconomic status^{19, 29}).

In summary, healthy eating is not a purely individual challenge, but a societal one. An interdisciplinary review³¹ shows that most research emphasizes biological, psychological, and product-related predictors, while political influences on food choices are hardly considered. However, it is not enough to call on consumers:in to be more conscious of their food choices and to encourage healthy eating. For example, according to Leng et al.¹⁹ blame and shame strategies directed at individuals that deny the underlying pathology of obesity are ineffective or possibly even counterproductive. The factors that promote an obesogenic environment must be identified and remedied. At the same time, an environment must be created in which it is easy to make healthy choices.