Why we are still failing to measure the nutrition transition

Correspondence to Dr Helen L Walls; helen. walls@ lshtm. ac. uk IntroduCtIon Malnutrition in all its forms—both underweight and micronutrient deficiencies, as well as overweight, obesity and associated non-communicable disease—is a global health issue, with the majority of cases arising in low-income and middle-income countries (LMICs). Much of this malnutrition, particularly shifts towards an increased prevalence of overweight and obesity, is driven by dietary changes described as the ‘nutrition transition’, whereby populations move from traditional diets high in fibre and micronutrients, to more highly processed diets high in sugar, fat, salt, low in fibre and less nutrient dense– with these dietary changes accompanied by changes in eating behaviours and physical activity patterns. Ultraprocessed food products have been defined by Monteiro et al as ‘not entirely or mostly made from foods, but from industrial ingredients and additives, and are highly profitable’. Distinctions are made between processed foods that have undergone limited processing and are not so problematic for diets (or are indeed healthy) and more highly processed or ‘ultraprocessed’ products that are often particularly unhealthy (eg, burgers, frozen pasta, pizza and pasta dishes, nuggets and sticks, crisps, biscuits, bakery goods, confectionary, cereal bars, sugary drinks). As is widely recognised in public health, quality data are essential for the development of appropriate health policy and programmes. Thus, surveillance of trends in dietary patterns based on appropriate measurement is critical for understanding the nutrition transition in different country and community contexts and to inform an appropriate response. But despite the high burden of malnutrition, relatively little is known about actual food consumption in many populations and factors affecting this. Furthermore, there is recognised need for development of improved methods and metrics for agri-health research. 4 As we describe, standardised dietary assessment instruments are in their current form inadequate for assessing diets in the context of the nutrition transition.