What is more important? Measuring trends in child undernutrition correctly or interpreting them adequately?

Invited Commentary on Trends in mild, moderate, and severe stunting and underweight, and progress towards MDG 1 in 141 developing countries: a systematic analysis of population representative data. Stevens GA, Finucane MM, Paciorek CJ, Flaxman SR, White RA, Donner AJ, Ezzati M; Nutrition Impact Model Study Group (Child Growth). Lancet. 2012 Sep 1;380(9844):824-34. Epub 2012 Jul 5. A recent article by Stevens and colleagues1 presents new estimates of trends in malnutrition. While these are not very different to those already published, the interpretation of why progress is being achieved is limited and narrower than that which is commonly agreed. In preparing their paper the authors have not referred to a whole body of literature, that we would like to draw the reader’s attention to; noting for transparency that we have been closely involved with much of this, especially the Reports on the World Nutrition Situation.2 The 6th Report the SCN draws attention to the influence of maternal undernutrition and teenage pregnancy on child undernutrition rates through birth weight in Asia especially. The new methodology uses statistical techniques to estimate national and regional prevalence of underweight and stunted children under-five years for 1985–2011. These largely mirror those available from WHO (quoted by the authors) and by the UN (UN SCN) which are not quoted. The database itself is similar to that used by these others, but the loss of 35% (251 data points) of the data noted (although the reason in the figure is unclear, and the figure is not referenced from the text) is of concern. Equally a major task in obtaining a consistent set of data is adjusting for differing age bands, which is not clearly addressed. The models used have similarities to those used for many years in the World Nutrition Reports, although the variables used for interpolating prevalences are more restricted, and some found useful elsewhere, like lagging GNI/GDP, are not explored. The big picture on child nutrition trends is thus similar to what we already know: child undernutrition is far greater in Asia and Africa than in Southern America, and while progress has been greatest in Asia, in Africa there has been none. (The claim that stagnation or deterioration in Africa ‘had not been noted in previous analyses’ misses the results in the World Nutrition Reports, e.g. pp. 45–47 in ref 2, and earlier reports.) However the success in meeting this MDG goal is more extensive than they report, when looked at by sub-region: almost all of Asia and Central and South America are on track; Sub-Saharan Africa is not (Ref 2, p 47): Africa has more countries, so estimating by numbers of countries gives a pessimistic assessment. In fact, there have been stunning achievements in progress, especially for the massive population countries of S Asia; by population, a majority is reaching the goals. But new interpretation is where there is a real opportunity, as this can guide policy. The authors’ interpretation points to the importance of equitable economic growth and investment in pro-poor food and primary care programmes, but they give insufficient emphasis to the importance of the latter. Much of the progress that is due to deliberate programming of interventions comes from primary care and community-based programmes.3 In their description of primary care programmes the authors give too much emphasis to ‘food’ and especially to complementary feeding and treatment of diarrhoea but omit any reference to the importance of exclusive breast feeding. Another omission is the neglect of maternal malnutrition4, which as a crucial part of the first thousand days of life, needs more recognition.