Eat. Play. Go! Using Nuclear Science to Tackle Obesity

11 October 2013
Not having enough to eat is what we often think of as 'malnutrition'. But eating too much, of the wrong thing, and remaining mostly sedentary, leads to malnutrition of a different sort - obesity.<br /><br />
 (Photo: S. Henriques/IAEA).Obesity in childhood can cause chronic illnesses like heart disease, diabetes and osteoporosis later in life.<br /><br /> (Photo: E. Cody/IAEA).People become overweight and obese when they consistently consume more calories than they use every day. Matching the daily caloric intake to daily energy use leads to what nutritionists call energy balance, and is the key to maintaining a healthy weight in adults.<br /><br /> (Photo: E. Cody/IAEA)As opposed to adults, children need to consume enough calories not only to maintain daily activity, but also to grow and develop into healthy adults. <br /><br />(Photo: S. Henriques/IAEA)As a result, governments, (after extensive research often using nuclear stable isotope techniques) make recommendations to their populations about how much they need to eat to maintain energy balance and stay healthy. There are different recommendations for different age groups. <br /><br />(Photo: E. Cody/IAEA)Without the right data, health authorities might over or underestimate the population’s energy requirements and exacerbate the problems they’re trying to eliminate. <br /><br />(Photo: S. Gorisek/IAEA)For example, in 2002 after noticing a growing problem of obesity in the Latin American region, Chilean researchers involved in an IAEA nutrition project conducted a study that found international recommendations had overestimated how many calories children in the region needed to consume, thereby contributing to childhood obesity. <br /><br />(Photo: E. Cody/IAEA)The researchers used doubly labelled water - a nuclear technique measuring non-radioactive stable isotopes of hydrogen (<sup>2</sup>H) and oxygen (<sup>18</sup>O) in urine after children have consumed specially prepared water (a mixture of <sup>2</sup>H<sub>2</sub>O and H<sub>2</sub><sup>18</sup>O).  <br /><br />(Photo: S. Henriques/IAEA)Scientists then analyzed the urine samples to determine the rate at which the body produces carbon dioxide (CO<sub>2</sub>).  Because CO<sub>2</sub> production is the result of fat, carbohydrate and protein oxidation, measuring it shows body energy expenditure. <br /><br />(Photo: S. Henriques/IAEA)The doubly labelled water technique has also been used to help evaluate the success or failure of efforts to reduce obesity. <br /><br />(Photo: S. Henriques/IAEA)For example, a government might allocate more time for physical education and playing in school, or create more playgrounds and parks in urban areas.  <br />(Photo: S. Henriques/IAEA)Non-invasive isotopic techniques like doubly labelled water have been used to see whether such programmes are having the desired effect, if the children use more energy, or if the programmes are being negated by more sitting and lounging because of the greater exertion. <br /><br />(Photo: E. Cody/IAEA)The IAEA promotes the use and adoption of this technology by training scientists, providing experts to Member States, and partially funding the purchase of equipment necessary for research using doubly labelled water. <br /><br />(Photo: E. Cody/IAEA) <br /><br />© IAEA
Last update: 14 October 2014