A combination of industrialization, urbanization, economic development and globalization has resulted in rapid changes in diets and lifestyles for many populations. The impact of these changes is significant for the health and nutritional status of such populations, particularly in the developing world. The negative consequences of the nutrition transition include poor nutrition and decreased physical activity, with a corresponding increase in diet-related chronic diseases such as obesity, diabetes mellitus, cardiovascular disease, hypertension, stroke, osteoporosis and some cancers, particularly among the poor. The coexistence of chronic diseases and undernutrition of infants, children and women, and overnutrition in adults, has been referred to as the double burden of malnutrition. Stable isotope techniques are now in widespread use in applied nutrition, however, in this paper we discuss three of the techniques with particular relevance to the development and monitoring of nutrition interventions globally. These techniques include the doubly labelled water (DLW) technique of deuterium (2H) and oxygen- 18 (18O) to assess total energy expenditure (TEE), the use of 2H to estimate total body water (TBW) and assessment of body composition as well as the deuterium oxide ‘dose-to-mother’ technique to assess human milk intake in breastfed infants.