Longitudinal changes in processed food intake and their daily caloric contribution among Ghanaian populations living in Ghana and Europe: findings from the prospective Research on Obesity and Diabetes among African Migrants (RODAM) cohort study

Background: Dietary changes towards increased consumption of processed and ultra-processed foods are major contributors to obesity and non-communicable diseases worldwide. However, limited data exist on the intake of processed foods among Ghanaians living in Ghana and their migrant counterparts living in Europe. This study assessed changes in the intake of processed foods and their corresponding energy contributions among different Ghanaian populations. Methods: Data were collected from the Research on Obesity and Diabetes among African Migrants–prospective (RODAM-Pros) cohort study, which recruited Ghanaians living in rural and urban Ghana and Ghanaian migrants living in Amsterdam, the Netherlands between baseline (2011–2015) and follow-up (2019–2021). Dietary intake was assessed using standardized food frequency questionnaires. Foods were regrouped according to the NOVA classification, a system that categorizes food based on the degree of processing. Paired sample t-tests were used to determine the differences in mean daily intake (grams) of foods and energy contribution between baseline and follow-up. Results: Compared with baseline, ultra-processed food consumption decreased significantly among urban Ghanaians (−37.6%, −97.57 g/day, 95% confidence interval (CI) −129.66 to −65.48, p < 0.001) and migrants in Amsterdam (−31.1%, −168.90 g/day; 95%CI −241.54 to −96.26, p < 0.001) with no significant change in rural Ghana. The percentage of total energy from ultra-processed foods changed from 9.6 to 9.0% (p = 0.136) in rural Ghana, 15.9% to 13.9% (p < 0.001) in urban Ghana and 13.4% to 13.0% (p = 0.539) in Amsterdam. Conversely, processed food consumption increased across all sites: by 52.4% (+ 149.31 g/day, 95%CI127.70 to 170.92, p < 0.001) in rural Ghana, 31.4% (+ 96.67 g/day, 95%CI 75.15 to 118.19, p < 0.001) in urban Ghana and 29.0% (+ 62.91 g/day, 95%CI 44.18 to 81.63, p < 0.001) in Amsterdam. The percentage of total energy from processed food increased significantly from 20.8 to 39.5% (p < 0.001) in rural Ghana, 23.6% to 33.5% (p < 0.001) in urban Ghana and 7.2% to 12.9% (p < 0.001) among migrants. Conclusions: Across all Ghanaian population groups studied, dietary intake has shifted towards higher intake and caloric contribution of processed foods, while ultra-processed food consumption has declined in urban and migrant settings. Further research is needed to identify the drivers of these changes and their implications for cardio-metabolic health among Ghanaian populations.