Food insecurity: a critical public health nutrition concern.

Food security is a condition where 'all people, at all times, have physical, social and economic access to sufficient, safe and nutritious food which meets their dietary needs and food preferences for an active and healthy life' (1). However, according to the FAO, in 2015 there are still about 800 million undernourished people across the planet, of whom over 95 % live in underdeveloped countries (2). Even when there is no lack of food, food insecurity (FI) may manifest as low-quality diet. Low-nutrient, energy-dense foods are becoming increasingly accessible for economically disadvantaged segments of the population and their consumption is often associated with overweight and micronutrient deficiency (3,4). Food shortage and poor diet are violations of the food security principles and are the causes of a significant proportion of disease burden worldwide, limiting productivity and promoting premature disability and reduced longevity. FI is a vital issue on the public health nutrition agenda both in developing and developed countries. Therefore, measuring the magnitude of FI and evaluating the factors associated with its development are of importance for public health nutrition. The measurement of food security represents a major challenge since it should encompass the complexity of this phenomenon. According to Pérez-Escamilla and Segall-Corrêa (5) , experience-based FI scales are the only available direct measure of FI, which can be used for 'mapping, targeting, and understanding the determinants and consequences of food insecurity'. Most of these scales are based on the Household Food Security Supplemental Module (HFSSM) developed by the US Department of Agriculture in the mid-1990s, which is designed to capture the household food security experience and allow categorizing into different levels of FI (6). In several countries, instruments based in the HFSSM have been developed and evaluated in order to obtain a simple, valid, reliable and low-cost method to measure household FI (7,8). Beyond relying on the individual perception of FI and capturing its psychosocial dimensions, these scales have the advantage of offering comparable results even with the adaptations to each local socio-cultural setting and language (5). Studies in low-and middle-income countries In this issue of Public Health Nutrition, the theme of FI been addressed by researchers from four continents in seven articles that explore the issue using different approaches. In Uganda, a study validated an instrument designed to assess FI at the individual level, instead of applying a household-level tool as are most HFSSM-based questionnaires. The tool was composed …