|dc.description.abstract||Although obesity has been commonly considered an individual problem (including
unhealthy behaviours and genetic component), the steep rise of overweight and
obesity prevalence in the last three decades holds a strong association with
changes in food consumption. The causes of these rapid shifts are related to
different processes of globalisation that have shaped food consumption. Several
studies have identified trade liberalisation as a significant driver of the rise of
obesity. This thesis offers new insights into the associations between trade and
investment barriers, food supply chains and health by analysing three geographical
The first scale includes a longitudinal assessment of the link between food supply
chains and BMI for 145 countries from 1991 to 2013. This scale involved two
approaches: the construction of the Food Liberalisation Index (FLix); merging three
proxy variables that exemplified food processing, food trade and FDI in the food
industry. The relationship between FLix and BMI changes (from 1991 o 2013) was
tested through panel regression. The results showed that changes in BMI are
positively and significantly associated with FLIx, evidencing the strong association
between the opening of trade barriers and BMI increase. Moreover, on a global
scale, the group trajectory analysis (from 1991 to 2013) of the three aforementioned
processes was carried out. The results from this exploration showed that LMICs
have undergone the most acute changes in their food supply chains since the
opening of trade barriers.
The impact of trade liberalisation was assessed at a local scale by testing the
relationship between food-outlet density and deprivation in Mexico City. First, a
longitudinal approach explored changes in supermarket density and deprivation
from 1990 to 2015, suggesting that the simplest type of supermarket (i.e. bodega)
has increased the most in more deprived areas. second, a cross-sectional approach
included an exploration of densities of street markets, marketplaces and
convenience stores in 2015.
The link between food outlet density and household food expenditure was explored.
Findings showed that households located in areas with higher densities of
supermarkets and convenience stores had higher expenditures on ultra-processed
foods. In contrast, households located in areas with high densities of street markets
had higher expenses for fresh food.
Finally, the thesis included a qualitative exploration individual motivations for
selecting a food outlet through a series of go-along interviews. The interviews were
comprised of residents of four areas with different levels of deprivation and took
place while participants did their food shopping. The analysis of the participants'
accounts suggested that motivations for selecting a food outlet depended mostly on
cost, quality and convenience.
Overall this thesis has contributed to the study of commercial determinants of health
by demonstrating the impact of TNCs on the food supply chain at three different
scales, and its influence in health and diet. Furthermore, this research provides
relevant evidence of the effects of local-food environments in the diet of Mexico City.||en