Int. J. Environ. Res. Public Health 2011, 8 1. Introduction 359 At the Millennium Summit in September 2000, world leaders adopted the UN Millennium Declaration, committing their nations to a bold global partnership to reduce extreme poverty and to address a series of time-bound health and development targets [1]. Among these Millennium Development Goals (MDGs) is a commitment to reduce the proportion of people who suffer from hunger by half between 1990 and 2015 [2], as set in the first MDG, with two targets monitored globally. Statistics show that hunger continues to be a dramatic problem in developing and emerging countries and that the progress towards the achievement of this goal is slow, with nearly 1 billion hungry people [3]. However, hunger and calorie deficits are only one part of the story. Many have access to the minimum amount of calories, but are deficient in one or more micronutrients. Micronutrient deficiencies, estimated to affect at least 2 billion people, are the cause of so-called ―hidden hunger‖. Since micronutrient deficiencies lead to a vast range of diseases and other health disorders, their decrease is likely to help the achievement of the other health-related MDGs such as Goals 4, 5 and 6 which call for reductions in child mortality, maternal mortality and prevalence of HIV-AIDS, malaria and other diseases, respectively. This paper examines the concept of hidden hunger and tries to sort out possible strategies to tackle the problem. We review the recent history of agriculture and nutrition policies and programmes with a focus on recent food-based approaches to improving micronutrient deficiencies, and some insights into the possible benefits of a more ―food and nutrition system‖ approach to combating hidden hunger. 2. A Needle in the Haystack: “Hidden Hunger” There are nearly 925 million hungry people in the World [3]. This is a rough estimate based on the prevalence of people who are assumed to have an energy intake below that which is required to maintain body weight, body composition and levels of necessary and desirable physical activity for long-term good health. The number of those hungry is higher than that in 2007 as a partial consequence of the 2007–2008 food price crisis, and the overall recent economic crisis. While the FAO is one of the most cited sources of data concerning hunger and food security, some experts disagree with the theoretical model in which these final numbers are obtained. The assumption is that hunger (often referred to as food security) is an exclusive outcome of the lack of sufficient calories for survival. The statistic is measured using a complex calculation which entails several steps: (1) identification of the total amount of food available in the country, through the ―food balance sheet‖, an input-output matrix where the quantities of food produced, traded, or eventually received under the form of food aid are registered; (2) subtraction of the quota of food which is assumed to perish and the one used for purposes different from human nutrition; (3) conversion of food into calories; (4) estimates of food distribution among households, first, and then within households based on household food, consumption or expenditure data; and (5) final estimates of the prevalence of hunger [4]. The FAO estimates show a decrease of those who are hungry during periods of increased national production because of assumed constant distribution of food nationally (household surveys are rarely