Fighting malnutrition with nuclear techniques

Nuclear techniques enable scientists and health professionals to identify the causes and consequences of malnutrition in children, enabling policymakers to develop strategies to combat obesity and stunting.

Nuclear science and technology have given them the tools to understand body composition and associate it with physiological changes that can lead to disease at later stages.

The use of stable isotopes, which are not radioactive, makes it possible to measure the amount of water and nutrients in the body, the amount of ingested nutrients absorbed by a person's body, and the rate of absorption, utilisation or synthesis of proteins, fats or carbohydrates.

Compounds labelled with stable isotopes are absorbed and behave in the body in the same way as their unlabelled counterparts, but because their molecular mass is different (isotopes of an element have the same number of protons, but one or more additional neutrons, their molecular mass is higher), they can be tracked.

For example, to measure the percentage of water and fat in the body, a person is given a special water drink rich in deuterium, which is a stable isotope of hydrogen. A few hours after the intake to allow time for the isotope to spread evenly in the body water, a sample can be taken in the form of saliva or urine and the amount of deuterium measured. Since the technicians know the amount of labelled water they have given to the patient and have measured the amount and proportion of labelled molecules in the body water, they can calculate the amount of liquid in the body.

From this, they can calculate the amount of non-adipose tissue, taking into account that water makes up 73% of the weight of non-adipose tissue. The difference between the body weight and the amount of non-adipose tissue corresponds to the amount of fat. Depending on the degree to which the fat content deviates from the norm, technicians can prescribe a corresponding diet or make relevant recommendations regarding physical activity or, if necessary, include the intake of vitamins and minerals through food fortification or supplementary micronutrient intake, as a complement to the promotion of healthy eating and increased physical activity.

By applying these nuclear techniques, it is possible to check for protein and micronutrient deficiencies in diets, which are mainly composed of carbohydrate-rich foods, mainly during childhood, which can lead to obesity later in life.