OBJECTIVE: To assess the availability and marketing of ultra-processed foods (UPF) in modern retail food outlets (supermarkets and minimarts) in Kenya and associated factors.

DESIGN: This cross-sectional study was conducted in Kenya from August 2021 to October 2021. Variables included the geographic location and the socio-economic status (SES) levels, the food items displayed for sale and advertised in the stores, and locations in the stores such as the entrance.

SETTING: Three counties in Kenya (Nairobi - urban, Mombasa - coastal tourist and Baringo - rural). Each county was stratified into high and low SES using national poverty indices.

PARTICIPANTS: Food outlets that offered a self-service, had at least one checkout and had a minimum of two stocked aisles were assessed.

RESULTS: Of 115 outlets assessed, UPF occupied 33 % of the cumulative shelf space. UPF were the most advertised foods (60 %) and constituted 40 % of foods available for sale. The most commonly used promotional characters were cartoon characters (18 %). UPF were significantly more available for sale in Mombasa (urban) compared to Baringo (rural) (adjusted prevalence rate ratios (APRR): 1·13, 95 % CI 1·00, 1·26, = 0·005). UPF advertisements were significantly higher in Mombasa ((APRR): 2·18: 1·26, 3·79, = 0·005) compared to Baringo and Nairobi counties. There was a significantly higher rate of advertisement of UPF in larger outlets ((APRR): 1·68: 1·06, 2·67 = 0·001) compared to smaller outlets.

CONCLUSIONS: The high marketing and availability of UPF in modern retail outlets in Kenya calls for policies regulating unhealthy food advertisements in different settings in the country.