Keystones affecting sub-Saharan Africa's prospects for achieving food security through balanced diets.

Socio-economic dynamics determine the transition from diets characterized by the risk of famine, to those characterized by the risk of diet-related non-communicable disease (DR-NCD). This transition is of particular concern in Sub-Saharan Africa (SSA) in which key socio-economic interactions that influence diet include economic growth and rapid urbanization; inequality and a growing middle class; and obesogenic food environments and an increasing prevalence of DR-NCD. In each case, countries in SSA are among those experiencing the most rapid change in the world. These interactions, styled as 'keystones', affect the functioning of other components of the food system and the diets that result. Data from the wealthiest quartile of countries in SSA suggest that these keystones may be increasing the risk of DR-NCD, widening inequalities in health outcomes due to unbalanced diets. To address this, new consumer and government capabilities that address these keystones are required. Food sensitive urban planning, supporting food literacy and fiscal management of consumption are examples.