Anaemia - a condition where a person has reduced haemoglobin levels or red blood cells, which means they can't get oxygen to body tissues. It is caused by a lack of iron, folate, vitamin B12 and other nutrients, and can be triggered by infectious diseases such as malaria and hookworm infestation.

Double burden (of malnutrition) – the presence of both undernutrition and overnutrition (being overweight or obese) in rapidly urbanising developing countries has created what is known as a 'double burden' that these nations struggle to treat. (One Goal often talks about the double burden of malnutrition in Asia.)

First 1,000 days – the critical period from the start of a woman's pregnancy and her child's second birthday. Good nutrition in this period can have a profound impact on a child's ability to grow, learn and rise out of poverty. Babies who are malnourished in the womb have a higher risk of dying in infancy and are more likely to face lifelong health problems.

Folate deficiency – the lack of folic acid, a B vitamin, which can cause a type of anaemia. Folic acid is present in foods such as green leafy vegetables, fresh fruits, cereals, meats and yeast.

Food fortification – the addition of essential nutrients, such as vitamin A, iron, iodine and folic acid, to staple foods and condiments such as salt.

Food security – the extent to which people can get the nutritious food they need to live a healthy and active life.

Home fortification – when recipients sprinkle multi-micronutrient powder onto food after they have cooked it. It is a viable option when households have food that lacks important micronutrients.

Hunger – in its most basic sense, this is the physical sensation of needing food, and is a more general term than malnutrition or undernutrition. But it can go on for weeks and months while sufferers live on significantly less than the recommended 2,100 calories per day that the average person needs to lead a healthy life.

Iodine deficiency – the most prevalent, yet easily preventable, cause of mental impairment. Serious iodine deficiency during pregnancy can result in stillbirth and problems with a child's mental development. Iodine occurs naturally in some foods, including dairy products and fish.

Lipid-based nutrient supplements – products designed to deliver nutrients to vulnerable people, where the majority of the energy provided is from lipids, or fats.

Malnutrition – covers a range of problems, including being underweight or obese, and is the largest single contributor to disease in the world. Even if people get enough food, they become malnourished if what they eat lacks the proper amounts of nutrients.

Micronutrients – essential vitamins and minerals required by the body in miniscule amounts. They enable the body to produce enzymes, hormones and other substances essential for proper growth and development.

Obesity – you are considered obese when you have a Body Mass Index of 30 to 39.9 (normal is BMI 18.5-24.9). Obesity increases the risk of chronic diseases including diabetes, cardiovascular diseases and cancer. Once considered a problem only in high-income countries, obesity is now dramatically on the rise in low- and middle-income countries.

Overweight – you are considered overweight when you have a BMI of 25-29.9. Being overweight increases the risk of chronic diseases including diabetes, cardiovascular diseases and cancer.

Starvation – results from a partial or total lack of essential nutrients for a long time. Often, because the body is so weak, someone who is starving will die of an infectious disease before their body shuts down from lack of sustenance.

Stunting – when a child is too short for their age, compared to a reference population of well-nourished and healthy children. Stunting is caused by prolonged inadequate nutrition, including poor maternal nutrition and poor infant feeding practices. In developing countries the rate of stunting is as high as one in three.

Undernutrition – a type of malnutrition that results from not eating enough, or from the body's failure to absorb nutrients properly. It includes being underweight for one's age, too short for one's age, dangerously thin, and deficient in vitamins and minerals. Undernutrition is considered the number one risk to health worldwide.

Underweight – measured by comparing the weight-for-age of a child with a reference population of well-nourished and healthy children. Being underweight increases the risk of malnutrition.

Vitamin A deficiency – the leading cause of preventable blindness in children, it also increases the risk of disease and death from severe infections. In pregnant women it causes night blindness and may increase the risk of maternal mortality.

Wasting – reflects a severe process that has led to substantial weight loss. Also known as acute malnutrition, wasting is calculated by comparing the weight-for-height of a child with a reference population of well-nourished and healthy children. This measurement is often used to assess the severity of emergencies.

Zinc deficiency – people get zinc through a diverse diet that includes meats and fish. Children are especially vulnerable to zinc deficiency, which weakens their immune system and means they are unable to recover from illness. Each year, a lack of zinc leads to the death of 450,000 children under the age of five worldwide, according to UNICEF.

Sources: GAIN, the World Food Programme, World Health Organisation, UNICEF, Merck, Johns Hopkins University, Zinc Saves Kids, Home Fortification Technical Advisory Group, United Nations Standing Committee on Nutrition, and 1,000 Days.

See this article on The Guardian Improving Nutrition Hub.