The relationship between agricultural commercialisation and nutrition is empirically contested, with findings suggesting different trends for different indicators, and across different contexts. Using novel cross-sectional survey data from a study of commercialisation in four African countries, this paper aims to understand associations and trade-offs between agricultural commercialisation and food consumption using three different indicators: household perceptions of their own food security; the dietary diversity of adult women and men; and the consumption of unhealthy ultra-processed foods and drinks. We find that a higher level of commercialisation is associated with respondents perceiving the household as more food secure in three countries and hypothesise that this relationship only holds where food price inflation remains low. Perception of better food security is subsequently associated with better reported dietary diversity, but diversity remains low in all countries even in the most commercialised households, and men's dietary diversity overtakes women's, on average, at higher levels of commercialisation. Ultra-processed foods were not highly consumed in our samples but were also linked with increasing commercialisation. Through this analysis, we show that commercialization and food consumption outcomes are linked in both positive and negative ways - and that both, retaining own food production, and the food market context, plays a moderating role, as does household experience of uncertainty in transition to commercial agriculture. Findings for policy in the context of inevitable but highly varied forms of agricultural commercialisation in Africa therefore include ensuring that diverse nutritious foods are available and affordable in local markets, but also that household food security and diets are socially supported through the process of transition where commercialisation is pursued.