Two driving forces of change in lifestyle and health outcome regarding immigrants should be taken into account. One is the nutrition transition, which is a global trend. The other is the process of dietary acculturation which occurs with migration.
The nutrition transition is driven by industrialization and globalization of the food market. It started in high-income countries, but has spread to low-income countries in the last decades and has escalated, first in urban areas and also lately in rural areas (22
). It has led to an increased supply of what has been described as ultra-processed foods, which are cheap, rich in fat, sugar, and other refined carbohydrates (8
). The result has been increased intake of energy-dense foods and snacks, sugary drinks, and a shift toward more meat and dairy. Concomitantly, the intake of whole grains and legumes is reduced (8
). Urban areas may have high availability of fruits and vegetables, but prices determine access. Urbanization has led to less physical activity and thus a lesser need for food energy.
The other driving force – dietary acculturation – has been defined as ‘the process that occurs when members of a minority group adopt the food choices and eating patterns of the host country’ (1
). The concept ‘acculturation’ is multidimensional and includes changes in identity, attitudes, and values that accompany an individual's movement from their original culture toward the mainstream culture in the new country (26
). Dietary acculturation does not appear to move linearly from one end of the acculturation continuum to the other. Available research indicates that immigrants may find new ways to compose traditional dishes and meals, to exclude foods, and consume new foods (27
Satia-Abouta et al. (1
) have proposed a model of dietary acculturation which focuses on factors that may have an impact on the trajectories leading to new dietary habits. They suggest that socioeconomic and demographic factors together with the cultural factors that immigrants bring along influence the degree of exposure to the host culture, which, in turn, leads to changes in psychological factors, taste preferences, and changes in food procurement and preparation, and thus dietary changes.
Another model, developed by Koctürk-Runefors (29
), focuses on the temporal process of dietary change and introduces ‘identity’ and ‘taste’ as two opposing forces affecting the change. Foods are divided into three main categories: ‘staple foods’ (carbohydrate-rich foods such as grains and tubers), ‘complementary foods’ (meat, fish, milk, eggs, vegetables, and lentils), and ‘accessory foods’ (fats, oils, herbs and spices, sweets, nuts, fruits, and drinks). It is further proposed that the staple foods are more closely tied to identity than the foods in the other categories, and will therefore be the last ones to change. Thus, the first change will be the intake of accessory foods, which are postulated to be less tied to cultural identity but driven by taste preference. Since these foods include fats, sweets and drinks, such changes may have large implications for health.
Even though nutrition transition and dietary acculturation are distinct processes with their own definitions, they have many similarities. Both are concerned with consumers’ encounter with increased availability of certain types of food that are easily favored, usually energy dense and highly processed, such as sugary drinks, snacks, and convenience foods. However, they also include a more stable supply of fresh foods, such as meat, fish, fruits, and vegetables. The process that immigrants from low-income countries (and often from rural areas), moving to high-income countries (and often to urban areas) go through, can be described as a more abrupt and radical form of nutrition transition.
The nutrition transition in the country of origin may affect the process of dietary acculturation after migration in several ways. If energy-rich and highly processed foods have become status foods, which very few can afford, it is likely that these foods also would be favored in the new country; and if more available and affordable, this would speed up the process of change. On the other hand, if the nutrition transition in the country of origin has come far, and people are using these foods already before they migrate, there might be less dietary change after migration.