7.3 What are the global challenges for nutrition?
Hunger and undernutrition

Caused by insufficient calories and other factors including poor sanitation, poor maternal nutrition and insufficient quantity and quality of food.

Leading to low body weight – of particular concern is stunting and wasting in children, which damages physical wellbeing and can also lead to cognitive impairments.

Micronutrient deficiencies

Lack of essential vitamins and minerals needed in small but adequate amounts by the body for proper growth and development.


Excessive consumption of calories and undesirable nutrients (saturated fat, sugar, refined carbohydrates, salt, alcohol), leads to obesity and non-communicable diseases

Poor diets (i.e. high in saturated fat, sugar, refined carbohydrates, salt and alcohol and low in fruit and vegetables and fibre) are a risk factor for non-communicable diseases (for example Type 2 diabetes) independently of whether someone is overweight or obese. 

Independently of diet quality, obesity is associated with increased risk of non-communicable diseases (NCDs).

Diets excessive in energy can lead to obesity and are also often poor in nutritional quality.

7.3.1 Malnutrition in all its forms is a global concern.

Malnutrition in all its forms is a global concern


  • 11% of the world’s population (794 million people) are estimated to be calorie deficient.
  • Nearly 25% of children under age 5 (161 million) are stunted (too short for their age).
  • 8% of children under age 5 (51 million) are wasted (they do not weigh enough for their height).
  • Prevalence is far higher in Sub Saharan Africa and South Asia.

Micronutrient deficiency

  • Over 30% of the world’s population (2 billion people) suffer from micronutrient deficiency. The 3 most common forms of deficiencies are iron deficiency anaemia, vitamin A deficiency and iodine deficiency.


  • 39% of adults are overweight (1.9 billion); 13% are obese (600 million).
  • 1 in 12 adults worldwide have Type 2 diabetes.
  • Over 6% of children under 5 are overweight or obese (42 million out of 652 million).

A growing number of countries (e.g. South Africa, India, and Mexico) now shoulder a "double burden" (more accurately triple) of malnutrition, namely the rapid rise in obesity and obesity-related chronic diseases coexisting with undernutrition and ongoing micronutrient deficiencies.

7.3.2 Some progress is being made in reducing undernutrition.

Some positive progress is being made in reducing the number of children under 5 years suffering from stunting and wasting, measured against targets set by the WHO’s World Health Assembly (viewable here).

Some progress is being made in reducing undernutrition

Adapted from International Food Policy Research Institute (2015)

For the poorest groups of society (especially in low income countries) a shift towards more energy dense food can be positive for nutrition.

Tackling undernutrition, as measured by World Health Assembly (WHA) indicators such as child stunting (children too short for their age) and wasting (children not weighing enough for their age), has shown positive trends.

However much work remains to be done to prevent total global undernutrition, with nearly 800 million people still living calorie deficient lives.

7.3.3 Micronutrient deficiencies are still widespread

Micronutrient deficiencies persist: the example of anaemia

Adapted from Stevens, et al. (2013)

  • 496 million non-pregnant women, 32 million pregnant women, and 273 million children were estimated to have anaemia in 2011.
  • Prevalence is highest in Central and West Africa and South Asia.

7.3.4 Health problems related to overconsumption are worsening

Health problems related to overconsumption are worsening: adults

International Food Policy Research Institute (2015)

All countries with WHA targets for adult obesity are reporting increased prevalence. Globally, the percentage of women who are obese is slightly higher than adult males, although the difference can be more significant in some regions, possibly due to cultural factors. The mean prevalence of adult obesity is greatest in high income countries but has increased across all regions. In comparison to the undernutrition targets (see above) no countries are on target to meet WHA adult obesity reduction goals.

Health problems related to overconsumption are worsening: pre-school children

Adapted from International Food Policy Research Institute (2015)

Obesity is rising globally in pre-school children, in both developed and developing countries.

In 2010, 43 million pre-school children (35 million in developing countries) were estimated to be overweight and obese.

92 million were at risk of overweight.

The worldwide prevalence of childhood overweight and obesity increased from 4.2% in 1990 to 6.7% in 2010. This trend is expected to reach 9.1% or 60 million, in 2020. 

Obesity in childhood is a particular concern because it tends to track through into adulthood. Obesity at an earlier age can mean earlier onset, and ultimately more severe health problems.

In developed countries lower income is associated with higher obesity: the UK as an example (women and children)

NOO (2012) Adult obesity and economic status.


Public Health England (2015). 


In developed countries, unhealthy diets have been shown to be cheaper sources of energy than healthy balanced diets. This economic factor has been seen to contribute to increasing obesity with poorer groups in high income countries, although the association is weaker with men than women.

See later in this chapter for more on socio-economic factors.

Similar patterns are found in other high income countries: France, for example

Adult obesity prevalence in France by household income, 1997–2012. Loring and Robertson (2014).

Obesity is a growing problem in many developed countries across income groups, but the problem is often greatest in lower income groups of society. The link between obesity and socio-economic status is strong, especially among women.