For the third year in a row, there has been a rise in world hunger. The absolute number of undernourished people, i.e. those facing chronic food deprivation, has increased to nearly 821 million in 2017, from around 804 million in 2016. These are levels from almost a decade ago.

The share of undernourished people in the world population – the prevalence of undernourishment, or PoU – may have reached 10.9 percent in 2017. Persistent instability in conflict-ridden regions, adverse climate events in many regions of the world and economic slowdowns that have affected more peaceful regions and worsened the food security, all help to explain this deteriorating situation.

The situation is worsening in South America and most regions of Africa. Africa remains the continent with the highest PoU, affecting almost 21 percent of the population (more than 256 million people). The situation is also deteriorating in South America, where the PoU has increased from 4.7 percent in 2014 to a projected 5.0 percent in 2017. Asia’s decreasing trend in undernourishment seems to be slowing down significantly. The projected PoU for Asia in 2017 is 11.4 percent, which represents more than 515 million people. Without increased efforts, the world will fall far short of achieving the SDG target of eradicating hunger by 2030.

Overall, there has been some progress regarding stunting and exclusive breastfeeding for the first six months of life. The number of stunted children has decreased from 165.2 million in 2012 to 150.8 million in 2017, a 9 percent decline. Yet, the number is still unacceptably high and the road to reaching the 2030 target is still long.

In 2017, 40.7 percent of infants below six months of age were exclusively breastfed, up from 36.9 percent in 2012. Rates of exclusive breastfeeding in Africa and Asia are 1.5 times those in Northern America where only 26.4 percent of infants under six months receive breast milk exclusively.

Conversely, anaemia among women of reproductive age is not improving. The prevalence of anaemia among women of reproductive age has risen incrementally from 30.3 percent in 2012 to 32.8 percent in 2016 with no region showing a decline. Shamefully, one in three women of reproductive age globally is still affected by anaemia, with significant health and development consequences for both women and their children.

In 2017, 7.5 percent of children under five – 50.5 million – were affected by wasting (low weight for height) consequently putting them at a higher risk of mortality. An analysis from 2013 indicated that 875 000 deaths (or 12.6 percent of all deaths) among children under five years of age were related to wasting, of which 516 000 deaths (7.4 percent of all deaths among under-fives) were related to severe wasting.

Since 2012, the global proportion of overweight children remains relatively stagnant, with 5.4 percent in 2012 and 5.6 percent (or 38.3 million) in 2017. Of these 38.3 million overweight children, 25 percent live in Africa and 46 percent live in Asia.

Adult obesity, on the other hand, is worsening. Adult obesity rates continue to rise each year, from 11.7 percent in 2012 to 13.2 percent in 2016. This means that in 2017 more than one in eight adults, or more than 672 million, in the world is obese.

The prevalence of obesity among adults in the world has been increasing steadily between 1975 and 2016 – and at an accelerated pace over the past decade. Adult obesity is highest in Northern America and the rate of increase in adult obesity is also the highest there. While Africa and Asia continue to have the lowest rates of obesity, an increasing trend can also be observed.

THE MULTIPLE BURDEN OF MALNUTRITION
As mentioned before, levels of childhood stunting and wasting persist across regions and countries; yet, simultaneously, there has been an increase in overweight and obesity, often in the same countries and communities with relatively high levels of child stunting. This coexistence of undernutrition with overweight and obesity is commonly referred to as the “double burden” of malnutrition. A large proportion of the world population is also affected by micronutrient (vitamin and mineral) deficiencies, often called “hidden hunger” because there may be no visible signs. Iron deficiency anaemia in women of reproductive age is one form of micronutrient deficiency.

Many countries have a high prevalence of more than one form of malnutrition. This multiple burden of malnutrition is more prevalent in low-, lower-middle and middle-income countries and concentrated among the poor. Obesity in high-income countries is similarly concentrated among the poor. The coexistence of multiple forms of malnutrition can occur not only within countries and communities, but also within households – and can even affect the same person over their lifetime.

PATHWAYS FROM FOOD INSECURITY TO MALNUTRITION
Poor access to food and particularly healthy food contributes to undernutrition as well as overweight and obesity. It increases the risk of low birthweight, childhood stunting and anaemia in women of reproductive age, and it is linked to overweight in school-age girls and obesity among women, particularly in upper-middle- and high-income countries. There are several pathways from inadequate food access to multiple forms of malnutrition.

Food insecurity (unreliable access to food) can contribute to child wasting, stunting and micronutrient deficiencies by negatively affecting the adequacy of food consumption. A diet characterized by insufficient intake of calories, protein, vitamins and minerals will impede foetal, infant and child growth and development. Such diets contribute to maternal undernutrition and consequently to higher risk of low birthweight, which in turn are both risk factors for child stunting. The stress of living with food insecurity can also have a negative effect on the nutrition of infants by compromising breastfeeding. Although it may appear to be a paradox, food insecurity can also contribute to overweight and obesity. Nutritious, fresh foods often tend to be expensive. Thus, when household resources for food become scarce, people choose less expensive foods that are often high in calories and low in nutrients. This is particularly true in urban settings and upper-middle and high-income countries, although the negative effect of food insecurity on diet quality has been documented in low-, middle- and high-income countries alike.

There are also psychosocial factors that link food insecurity to obesity. The experience of not having certain or adequate access to food often causes feelings of anxiety, stress and depression, which in turn can lead to behaviours that increase the risk of overweight and obesity. These include patterns of binging or overeating when food is available (and continued availability uncertain), or choosing low-cost, energy-dense “comfort foods” rich in fat, sugar and salt. Such foods have been found to have physiological effects that reduce stress in the short term.

Disordered eating patterns and food deprivation are another component linking food insecurity to malnutrition. “Feast-and-famine” cycles cause metabolic changes that have been associated with an increase in body fat, decrease in lean muscle mass, and more rapid weight gain when food becomes plentiful.

In addition, maternal and infant/child food deprivation can result in foetal and early childhood “metabolic imprinting”, which increases the risk of obesity and diet-related on-communicable chronic diseases later in life. Maternal undernutrition – as well as overweight– caused by lack of stable access to adequate diets can cause metabolic, physiological and neuroendocrine changes in children, fueling intergenerational cycle of malnutrition.

The coexistence of multiple forms of malnutrition means that the two pathways described above do not work in isolation but rather impact each other. In this way, the undernutrition linked with food security might at the same time be linked with overweight and obesity. As described, food insecurity is associated with low birthweight in infants. Low birthweight is a risk factor for child stunting, which in turn is associated with overweight and obesity later in life. According to WHO, “Children who have suffered from undernutrition and were born with low birthweight or are short for-age (stunted) are at far greater risk of developing overweight and obesity when faced with energy-dense diets and a sedentary lifestyle later in life.” It is also worth noting that children who are stunted have a higher risk of being simultaneously overweight.

WHAT CAN BE DONE?
There is a need to implement and scale up interventions aimed at guaranteeing access to nutritious foods and breaking the intergenerational cycle of malnutrition. The 1 000 days between conception and a child’s second birthday is a window of unsurpassed opportunity to both prevent child stunting and overweight and promote child nutrition, growth and development with lasting effects over the child’s life. Exclusive breastfeeding in the first six months and adequate complementary foods and feeding practices up to two years of age are key to ensuring normal child growth and development during this crucial window of opportunity.

Access to safe, nutritious and sufficient food must be framed as a human right, with priority given to the most vulnerable. Policies must pay special attention to the food security and nutrition of children under five, school-age children, adolescent girls and women in order to halt the intergenerational cycle of malnutrition. A shift is needed towards nutrition-sensitive agriculture and food systems that provide safe and high quality food, promoting healthy diets for all. (FAO)