A diet is the set of food substances that constitutes the nutritional behavior of living things. The concept comes from the Greek diaita, which means "way of life". Diet is therefore a habit and represents a way of living. Sometimes the term is used to refer to special diets for weight loss or to combat certain diseases, although these cases represent changes in the diet and not the diet itself. According to the diet they follow, living beings can be qualified in a variety of ways: carnivores (meat eaters), detritavores (feed on dead organic substances), herbivores (ingesting plants and fruits), insectivores (insects), omnivores system can digest meats and vegetables) or cannibals (eat members of the same species), among others. The human being is omnivorous by nature, although, for ideological or religious reasons, many choose to be vegetarians (they refrain from eating meat and fish). Human food is not determined solely by biological considerations, as it also takes into account social, economic and cultural factors. Many times, the diet is conditioned by the availability of food, which depends on the climatic conditions and geographical location of each region. Let us also not forget the personal factors that determine a diet, such as taste, influence of advertising of certain foods, aesthetic preferences and other issues. The ease of obtaining certain foods, the climatic conditions and social habits make each country and region have their own diet. Argentina, for example, has one of the highest rates of beef consumption in the world. Already, the United States is more likely to eat large amounts of "junk food" food, that is, foods with low nutritional value and high levels of fats or sugars, as is the case with hamburgers. This diet has caused an epidemic of obesity within the American population.