Global, regional and country trends in underweight and stunting as indicators of nutrition and health of populations.

Stunting and wasting provide indicators of different nutritional deficiency problems, the causes of which are well established. Underweight based on weight-for-age cannot distinguish between these two and is therefore not useful to target programs and has limited value for tracking progress. Stunting reduces later school attainment and income as adults and increases the risk of obesity and noncommunicable diseases in later life. Globally, the estimated number of stunted children is decreasing, but is not on track to meet the goal of 100 million by 2025 (165 million), and there has been little change in the number of children suffering from wasting since 2004. Stunting and wasting provide excellent indicators of inequity. For example, from 1990 to 2010, the number of stunted children in Asia declined from 188.7 to 98.4 million, while in sub-Saharan Africa there was essentially no change in prevalence, and the number of stunted children increased from 45.7 to 55.8 million. Recent global development movements are recognizing the need for robust measures of trends in nutritional status of children, particularly during the critical first years of life. Such measures are needed to track progress and improve accountability, and should be aspirational to mobilize sufficient investment in nutrition.