The second Hunger and Nutrition Commitment Index (HANCI) has just been launched, providing detailed evidence on efforts to reduce hunger (ten indicators) and undernutrition (12 indicators) in 45 developing countries.
The data show that the richer among these countries often do better - more resources should, after all, mean better outcomes. They also show that some poorer countries have been improving their performance despite difficult circumstances. Brazil, Guatemala, Madagascar, Malawi, Nepal, Peru and Tanzania came out as highly committed to taking action, with Burundi and Liberia making progress on reducing chronic hunger and undernutrition. 
According to the UN's Food and Agriculture Organization, 842 million people were suffering from chronic hunger between 2011 and 2013 - about 12 per cent of the global population. Undernutrition contributed to 45 per cent of the deaths of children under the age of five. And, in the first 1,000 days of life, it has long-term and irreversible effects, including on cognitive skills that can reduce an individual's potential for learning and earning.
To address such a comprehensive problem, effective, joined-up healthcare systems and hunger and nutrition interventions are necessary. These need a proper scientific basis - so evidence-based policies are crucial. But so is the delivery of interventions, and political commitment to improve delivery.
Another new study, which looked at effective leaders in nutrition, emphasised "the importance of locally collected and commissioned research, knowledge and data", as well as nationally relevant research. 
Elise Wach, the specialist who interviewed key experts in Bangladesh, Ethiopia, India and Kenya for the study, stresses that, while evidence is necessary, it is not enough. She tells me: "Getting effective policies in place requires an ability to understand the perceptions, priorities and relationships between different stakeholders - both within the (often fragmented) nutrition communities as well as among the broader policy actors." From here, she says, a leader might work to build alliances or to tailor how the problem is framed for different stakeholders.
Champions for effective delivery of national nutrition policies need to marshal the evidence, for sure - but they also need other skills. They can be dealing with a policy environment where rhetorical commitment from political leaders is higher than real commitment, where complex multisectoral coalitions need to be built and maintained, and where there are donor and community interests at play.
Roger Williamson is an independent consultant and visiting fellow at the Institute of Development Studies at the University of Sussex, United Kingdom. Previous positions include organising nearly 80 international policy conferences for the UK Foreign Office and being head of policy and campaigns at Christian Aid.
 Dolf te Lintelo and others The Hunger And Nutrition Commitment Index (HANCI 2013) (Institute of Development Studies, June 2014)
 Dolf te Lintelo Which 7 countries are most committed to ending hunger? (The Guardian, 3 July 2014)
 Nicholas Nisbett and others What are the factors enabling and constraining effective leaders in nutrition? A four country study (Institute of Development Studies, 30 June 2014)