This project is a collaboration between International Atomic Energy Agency (IAEA), FAO Regional Office for Asia and The Pacific, and Mahidol University, Thailand to carry out the study on doubly-labeled water for assessment of total energy expenditure and body composition among infants and young children aged 6-23 months old. Thailand conducted a longitudinal study with participation from 4 other countries, namely, Pakistan, Philippines, Sri Lanka and Vietnam, in undertaking the same assessments in a cross-sectional design.

The current international recommendations on energy requirements for children aged 6-24 months were established based on data from the Western populations. More human data of healthy children from the developing countries where the living conditions may not be as favourable for child growth and development would be needed to ascertain the validity of the global recommendation. The role of the doubly-labelled water (DLW) technique in measuring total daily energy expenditure to derive energy requirements for humans was also highlighted. Low and middle income countries in Asian countries have undergone the nutrition transition and malnutrition on both ends of the spectrum emerge as significant nutrition challenges during this critical period of growth. Unfortunately, data on body composition, i.e., the relative amounts of fat and lean or fat-free tissue which constitutes quality normal growth beyond anthropometric measurements are scarce. These data will also be needed to guide the infant and young child feeding (IYCF) recommendations for good nutrition and health and to prevent all forms of malnutrition in the region.

This project addressed the need to fill the information gap for the region, and potentially be included for making revision on energy requirement recommendations for infants and young children (IYC) for Asia and beyond. Building on the previous technical cooperation between institutions in Southeast and South Asia with the International Atomic Energy Agency (IAEA) on stable isotopic techniques for health and nutrition well-being, this project is a collaboration between IAEA, FAO Regional Office for Asia and The Pacific, and Mahidol University, Thailand to carry out the study on doubly-labeled water for assessment of total energy expenditure and body composition among infants and young children aged 6-23 months old. Thailand conducted a longitudinal study with participation from 4 other countries, namely, Pakistan, Philippines, Sri Lanka and Vietnam, in undertaking the same assessments in a cross-sectional design.

Inclusion Criteria for Mothers:

• Being aged >18 y old
• Being non-smoker
• Gestational age at delivery 37-41weeks
• Belonging to the major ethnicity of the country
• Having any socio-economic status
• Willing to sign informed written consent

Inclusion Criteria for Infants:

• Healthy baby
• Full term
• Having birth weight between 2.5 and 4.0 kg
• Height-for-age Z score and weight-for-height Z score at or above -2SD
• Being exclusively or predominantly breast-fed for at least 3 months

Exclusion Criteria for Mothers:

• Mothers: having chronic diseases, e.g., gestational diabetes were excluded.

Exclusion Criteria for Infants:

• Having inborn errors or chronic diseases e.g., celiac diseases
• Taking special supplement, e.g., RUTF.

Apparently healthy infants and young children aged 6-23 months of both sexes, belonging to the major ethnicity of the country, and having any socio-economic status.

IAEA repository upon approval

2025 onward

Upon approval