Nutritional and Health-Related Environmental Studies (NAHRES)

Frequently Asked Questions

This section is intended to provide hints and answers to some Frequently Asked Questions (FAQ) in relation with the activities of the International Atomic Energy Agency (IAEA) in Nutritional and Health-Related Environmental Studies (NAHRES). For further questions and answers please contact NAHRES. We are open to suggestions and comments on these items, and any feedback is most welcome.


1. Why does IAEA have projects in the field of nutrition?

2. How can nuclear techniques be used to address priority areas in nutrition?

3. What are the advantages of stable isotope techniques?

4. Are stable isotope techniques safe?

5. Is the use of dual-energy X-ray absorptiometry (DXA) safe?

6. How can we receive support?

Why does IAEA have projects in the field of nutrition?

The Department of Nuclear Science and Applications (NA) helps member states use nuclear techniques to promote sustainable development in human health. Good nutrition is fundamental to human health at all ages. In particular, stable isotope techniques and dual-energy X ray absorptiometry (DXA) can be used to monitor and evaluate nutritional interventions to promote health. The work of the Nutrition Section has a strong focus on maternal and child health (Millennium Development Goals 4 and 5). Nutrition is also an integral part of MDG 1 (To eradicate extreme poverty and hunger) and MDG 6 (To combat HIV/AIDs and other diseases).

How can nuclear techniques be used to address priority areas in nutrition?

The first 1000 days of life from conception to two years of age is a critical window of opportunity when physical and mental capacity is established. In general, healthy mothers have healthy babies, and optimal growth and development is achieved by exclusive breastfeeding for six months, followed by the introduction of appropriate complementary foods and continued breastfeeding for up to two years (WHO recommendations). Malnourished mothers are more likely to give birth low birth-weight babies, who are not only vulnerable to malnutrition and infectious diseases early in life, but are also at increased risk of developing obesity and related non-communicable diseases, like diabetes and heart disease, later in life.

Stable isotope dilution techniques can be used to assess:
  1. The quantity of human milk consumed by breastfed babies, and whether they are exclusively breastfed or not, and to evaluate breastfeeding promotion and infant feeding education and counselling programmes by the deuterium oxide dose to mother technique.
  2. Healthy growth in terms of body composition (the proportion of fat and lean tissue); to monitor recovery from severe acute malnutrition and infectious diseases; to assess associations between body composition and disease risk in later life by predicting body composition from total body water using deuterium dilution techniques.
  3. Changes in energy expenditure and physical activity following lifestyle or clinical interventions by the doubly labelled water technique for assessment of total daily energy expenditure.
  4. The bioavailability of pro-vitamin A, iron and zinc from indigenous foods and diets, as influenced by nutrient fortification or dietary modifications.
  5. An individual’s body vitamin A stores.
Dual-energy X ray absorptiometry (DXA):
  1. Uses very low dose X ray imaging to measure body composition.
  2. Is a reference method for the measures of bone mineral density (BMD) to assess fracture risk and to diagnose osteoporosis.
  3. Measures bone mineral content (BMC) that is useful for paediatric studies and as part of the 4-compartment body composition model.

Is also a precise measure of whole body and regional soft tissue composition.

What are the advantages of stable isotope techniques?

Stable isotope techniques are safe, non-invasive and can be used from birth to old age.

Stable isotope techniques are more sensitive and specific than conventional techniques.

Stable isotope techniques can be used in community settings.

Stable isotope techniques do not change the behaviour you are trying to measure e.g. breastfeeding practices, physical activity (or inactivity).

Are stable isotope techniques safe?

There is no radiation hazard associated with stable isotopes.

Stable isotopes are present everywhere including the air we breathe, the food we eat, the water we drink and in our bodies.

Is the use of dual-energy X-ray absorptiometry (DXA) safe?

DXA systems generate very low levels of ionizing radiation and are a useful technique for measuring body composition from newborns to very obese patients. Although no ionizing radiation exposure can be considered absolutely safe, the risks associated with a DXA scan are too low to quantify. The effective patient dose from a DXA scan is similar to the one received on average from one or two days of exposure to natural background radiation at sea level. Due to increased radiosensitivity of children, DXA procedures are optimized to use as low as reasonably achievable doses when performing DXA scans of children.

How can we receive support?

If you qualify, you can receive support through the Technical Cooperation Programme

or through the Coordinated Research Programme.