This paper is concerned with: (i) challenges to food systems in Africa, Asia, and Latin America caused by urban development, (ii) how existing food systems respond to these challenges, and (iii) what can be recommended to improve their responsiveness. We define 'urban food systems' as food systems related to cities by material and human flows. Urbanisation poses challenges related to food and nutritional security with co-existence of multiple forms of malnutrition (especially for women and children/adolescents), changing employment (including for women), and environmental protection. It is widely acknowledged that contemporary food systems respond differently to these challenges according to their traditional (small-scale, subsistence, informal) versus modern (large-scale, value-oriented, formal) characteristics. We go beyond this classification and propose six types of urban food systems: subsistence, short relational, long relational, value-oriented SME-driven, value-oriented supermarket-driven, and digital. They correspond to different consumers' food environments in terms of subsistence versus market orientation, access through retail markets, shops or supermarkets, diversity of food, prices and quality attributes. Urban food supply chains differ not only according to scale and technology but also according to the origin of food (rural, urban or imports) and the perishability of the product. We stress the complementarity between short chains that supply many perishable and fresh food items (commonly nutrient-dense) and long chains that involve collectors, wholesalers, retailers, storage and processing enterprises for many staple food commodities rich in calories. More and more small and medium enterprises are upgrading their business through technologies, consumer orientation, and stakeholders' coordination patterns, including food clusters and alliances. Urban food systems based on micro, small and medium enterprises (MSMEs) have proven resilient in times of cr