There is rising concern that the ongoing wave of urbanization will have profound effects on
eating patterns and increase the risk of nutrition-related non-communicable diseases. Yet, our
understanding of urbanization as a driver of food consumption remains limited and primarily
based upon research designs that fail to disentangle the effect of living in an urban environment
from other socioeconomic disparities. Data from the Tanzania National Panel Survey, which
tracked out-migrating respondents, allow us to compare individuals’ dietary patterns before and
after they relocated from rural to urban areas and assess whether those changes differ from
household members who stayed behind or moved to a different rural area. We find that
individuals who relocated to urban areas experience a much more pronounced shift away from
the consumption of traditional staples, and towards more high-sugar, conveniently consumed
and prepared foods. Contrary to what is often claimed in the literature, living in an urban
environment is not found to contribute positively to the intake of protein-rich foods, nor to diet
diversity. Though we do not find a strong association with weight gain, these changes in eating
patterns represent a clear nutritional concern regarding the potential longer-term impacts of
urbanization. Our results however also indicate that the growth of unhealthy food consumption
with urbanization is largely linked to rising incomes. As such, health concerns over diets can
be expected to spread rapidly to less-urbanized areas as well, as soon as income growth takes
off there. Our findings clearly call for more in-depth research that may help to improve health
and food and nutrition security as well as correctly predict food demand and adapt trade,
agricultural and development policies.