The role of fast-food outlet exposure in Body Mass Index

The overweight epidemic is among the most pressing public health challenges in Dutch society. The prevalence of overweight among Dutch adults has increased from 33% in 1981 to 50% in 2022. Moreover, it is expected that over 62% Dutch adults will have overweight by 2040. A high exposure to fast-food outlets, such as large fast-food chains and kebab stores, may be part of the explanation for this increase of overweight in Dutch society.

We used data from Lifelines, a large population-based cohort in the Northern Netherlands, to investigate the role of fast-food outlet exposure in Body Mass Index (BMI, a measure of overweight). Over three-quarters of Lifelines participants had at least one fast-food outlet within one kilometer around their home. Participants with more fast-food outlets within one kilometer had a higher BMI and increased more in BMI over time. Furthermore, increases in fast-food outlet exposure, for instance because of moving houses to an area with more fast-food outlets, was related to greater BMI increases. People living in vulnerable neighbourhoods and young adults – and especially young adults with an elevated genetic risk of a higher BMI – were particularly susceptible to unhealthy fast-food environments. Remarkably, healthy food outlets were not a not buffer in the relationship between fast-food outlet exposure and BMI.

Results of this thesis show that fast-food outlet exposure may be part of the explanation why overweight has increased in the population. Policies towards healthier food environments are needed to support healthier lifestyles and address the epidemic of overweight.