Three biological cycles to be taken seriously to achieve global nutrition goals


As we start a new year, it is worth taking stock of the flurry of new reports and research findings during 2014, which carry important messages and policy implications for people working at the interface of nutrition, food systems and agriculture. Three of the many papers stand out, because they each highlight biological cycles that are critical to good nutrition outcomes if appropriately tackled through evidence based policies and programming.[1]

The first is the nutrient cycle. While nutrition is about much more than bundles of nutrients, these nutrients matter.  Where do they come from? Ideally from the food that we eat, which  means mainly from plants and animals.  But, plants and animals don’t contain the nutrients humans need unless they themselves are adequately nourished; that is, only if they meet their own nutrient requirements to grow well and reproduce in a variety of often challenging environmental settings.

A report from the Montpellier Panel, released ahead of the International Year of Soils 2015, argues that governments, and their development partners, have overlooked and undervalued the importance of making it profitable and possible for farmers and livestock owners to invest in soil fertility.[2] In sub-Saharan Africa, the report suggests, the political and physical neglect of land quality has left 65 percent of soils degraded – unable to “nourish the crops the chronically food insecure continent requires.” The economic loss associated with the decline in Africa’s soil fertility is put at US$68 billion per year—at a time when the continent receives roughly US$47 billion in total external aid.[3]

This doesn’t mean that African agriculture is a failure. Far from it; solid productivity gains have been made in many parts of Africa in the past decade, and staple crop yields have been rising across the continent in the past decade.[4]  But nutrient-poor soils led to nutrient-poor food, and poorly nourished crops and livestock are less able to resist the droughts, pests and diseases that all too frequently pose a threat to yields and output.

How do we resolve this problem? Green mulching, composting, tree and crop-based nitrogen fixation, integrated soil and water management, and the application of organic and inorganic fertilizers all have a role to play. But for the poorest rural landholders, such investments have to be worth their while. The Montpellier report argues for improved land access and tenure rights, increased financial support for improved land management, more effective knowledge dissemination, market supports to improve the profitability of the agricultural enterprise, and multisectoral actions at scale that link agriculture through value chains to consumers who are better able to demand high quality, nutrient rich diets.

If investing in the nutrition of the land were to be made attractive, well-nourished soils could deliver up to US$1.4 trillion each year in higher crop production alone – 35 times higher than current economic losses. More food, more income from farming, more resources in the hands of women, less vulnerability to the vagaries of climate; these are some of the building blocks for good human nutrition from a production and food marketing lens.

The second cycle is the human lifecycle. Huh?  Yes, paying more attention to our own nutrient needs. Well, perhaps not mine or yours, but the nutrient needs of the world’s most vulnerable groups. The new Global Nutrition Report points to the long shadow of malnutrition–a shadow that starts by blighting the life of a child or an adolescent girl, but which has consequences that flow throughout their own lives and cascade down into subsequent generations.[5] A malnourished pregnancy often leads to poor birth outcomes. Child stunting, as demonstrated by the influential Lancet series on nutrition, begins in utero. Roughly 20 percent of stunting by age 3 can be ascribed to that child being born small for its gestational age, which in part reflects health and nutritional deficiencies during the pregnancy.[6] Poor nutrition from birth onwards is associated with impaired physical and mental growth, constraints to learning and health, lower work productivity later in life, and elevated risk of developing non-communicable diseases, such as diet-related diabetes and heart disease.

This means that combinations of actions must be promoted across several key sectors (like agriculture, health, education, WASH and more), focusing on the needs of vulnerable people at the moments in the life cycle when they are most vulnerable: pregnancy, infancy, childhood, adolescence, and womanhood. The first 1,000 days of life are indeed critical, but so too are other 1,000 day periods in a person’s life. Certain people beyond infants have key nutritional vulnerabilities, such as the elderly and yes, even some adult men. The nutrient needs of these diverse groups differ by age, sex and context. But all must be met if global goals are to be achieved. The Global Nutrition Report argues that significant resources and attention should be focused on all windows of nutritional opportunity, not just one; that national, local and global accountability for impact must be hugely improved; and that the generation of empirical evidence of progress is key keeping nutrition high on the policymaking agenda.

Finally, the third cycle is the nutrient digestive cycle; how humans take up, absorb and utilise the many dozens of minerals and vitamins (micronutrients) that are essential to maintaining life, growth and health. The nutrition community is increasingly focused on the gut microbiome as a potentially key locus for physiological interactions that promote or impede good nutrition. It has long been recognised that diarrhoeal diseases are linked to undernutrition, since undernourished children are more susceptible to infections causing diarrhoeal and other diseases that are associated with 50 percent of preventable child deaths. Less understood is how enteric infections contribute to undernutrition and even to poor cognitive outcomes through intestinal inflammations, altering intestinal barriers (increasing so-called ‘leaky gut’ syndrome), and/or reduced absorptive functions of the gut villi.

We are beginning to get answers to such questions, for example in the new special supplement of the journal Clinical Infectious Diseases.[7] It reports early findings from multi-country studies under the MAL-ED project (the Etiology, Risk Factors, and Interactions of Enteric Infections and Malnutrition and the Consequences for Child Health project). In 8 developing countries, MAL-ED aims to understand how enteric infections, with or without diarrhoea, affect gut function, illnesses and nutrition outcomes. MAL-ED suggests that damage to essential gut bacteria can lead to chronic malnutrition (stunting), and that this often happens in the period 3 to 6 months after birth as the infant is increasingly exposed a) to poor nutrient-quality complementary foods, potentially carrying food-borne pathogens, and b) a challenging sanitary and disease environment through which they crawl, tasting samples of that environment as they go.

More needs to be understood about the factors involved in the impairment of nutrient absorption in human biological systems.[8] But enough is already known to bring policy and investment focus to bear on making i) the food and water consumed by vulnerable people safer (in terms of contaminants of all forms), ii) effective hygiene and quality sanitation a national priority everywhere, and iii) promoting enhanced knowledge and behaviours at household and community levels on the importance of cleanliness, hygiene and good sanitation.

Why do we all need to know more about these nutrition cycles?  Because they all point to the need for multi-disciplinary understanding of nutrition problems and multisectoral/multi-policy solutions. Yes, nutrition is about empowerment and purchasing power and politics and poverty. But actions in those domains must be informed by, and take into account, the biological cycles that matter for nutrition.


By Patrick Webb

Policy and Evidence Adviser for the Global Panel


[1] If you are not a bench or lab scientist, please don’t stop reading: it matters even more to you than if you come to this with a biological sciences background. We, the ‘policy and programing’ community, need to think about this stuff to be able to achieve our common goals.

[2] Montpellier Panel. 2014. No Ordinary Matter: Conserving, Restoring and Enhancing Africa’s Soils. Montpellier, France.

[3] US$47 billion net total Overseas Development Assistance in 2012 (Organisation for Economic Co-operation and Development statistics: (Accessed December 10, 2014)

[4] AGRA (Alliance for a Green Revolution in Africa). 2013. Africa Agriculture Status Report: focus on Staple Crops. Nairobi, Kenya: AGRA.

[5] Global Nutrition Report. 2014. Actions and Accountability to Accelerate the World’s Progress on Nutrition. Washington, D.C.: International Food Policy Research Institute.

[6] Black R., C. Victora, S. Walker, Z. Bhutta, P. Christian, M. de Onis, M. Ezzati, S. Grantham-McGregor, J. Katz, R. Martorell, R. Uauy & the Maternal and Child Nutrition Study Group. 2013. Maternal and child undernutrition and overweight in low-income and middle-income countries. Lancet,

[7] The MAL-ED Network Investigators. 2014. The MAL-ED Study: A Multinational and Multidisciplinary Approach to Understand the Relationship Between Enteric Pathogens, Malnutrition, Gut Physiology, Physical Growth, Cognitive Development, and Immune Responses in Infants and Children Up to 2 Years of Age in Resource-Poor Environments. Clin Infect Dis. 59 (suppl 4): S193-S206 doi:10.1093/cid/ciu653.

[8] Spears, D. 2013. How Much International Variation in Child Height Can Sanitation Explains? Policy Research Working Paper No. 6351. Washington, D.C.: World Bank.