Int. J. Environ. Res. Public Health 2011, 8 363 This has led to the implementation of ―food-based‖ strategies [35-37]. The new emphasis on nutrition security and public health is well reflected in the definition of food security given at the 1996 World Food Summit (see above). This definition recognizes the presence of a third component of food security, namely food utilization, encompassing diet quality and child care practices (Figure 1). 3.2. Nutrition Policies During the 1970s, the focus of nutrition policies and programs was on protein-energy deficiencies. However, as the determinants of poor nutrition become more defined, it was clear that vitamins and minerals play a key role in improved nutrition outcomes. Many pioneers in the nutrition field promoted supplementation and fortification programs to treat obvious deficiencies, such as vitamin A to treat night blindness and iodized salt to treat goitre. These programs are still ongoing and have demonstrated improvements in select micronutrient deficiencies in the developing world. While there is large empirical evidence of projects based on food supplementation and fortification having improved the nutritional status of the targeted population, this type of intervention (at least in the way it was realized) has some weaknesses. First, these programs have been mainly concerned with the ―big three‖ micronutrients—vitamin A, iron and iodine. Though they are the most widespread as well as those with more significant effects on public health, there are many other essential nutrients whose role in human nutrition has been highly neglected. Second, projects have focused on single nutrient interventions: however, a person is likely to suffer from multiple micronutrient deficiencies [38,39]. What Allen defines as ―nutrition isolationism‖ does not reflect the reality that often people suffer from deficiencies in multiple nutrients [38]. The third limitation is that there is no universal coverage of micronutrient supplements geographically and in populations. Supplying supplements to the most vulnerable and isolated populations is a challenge, as is the case with zinc supplementation in managing diarrhea in sub-Saharan Africa. In population coverage, iron supplements are targeted only to children, adolescents and all women of childbearing age, while vitamin A supplements are targeted only to preschool children and postpartum women [38]. The final limitation of micronutrient supplementation programmes is that they follow a top-down, stop gap approach [36], and take on a short-term solution [17,26]. These technical interventions do address the root causes for the specific micronutrient inadequacies, but do not affect the overall quality of their diet to ensure dietary (along with important non-nutrient elements such as phytochemicals) needs are covered for long lasting health. Therefore, single-nutrient supplements, although critically important in tackling some of the vitamins and minerals deficiencies with large burdens, are unlikely to ensure a sustainable improvement of diets worldwide. In a few cases supplementation programmes have failed to improve the various nutritional indicators even in the short term. One clear example is the ―Accelerated Child Survival and Development programme‖, implemented by UNICEF in 11 West African countries between 2001 and 2005. One central pillar of this programme consisted in the delivery of vitamin A supplements. A comprehensive evaluation in Benin and Ghana shows that: (1) there was no reduction in child wasting in Benin due to the intervention, while child wasting increased in Ghana; and (2) there was no significant reduction of childhood mortality due to the project [40].