The heat is on: Thermal cameras could aid fight against obesity

Child sits as infrared camera measure thermogenesis. Source: University of Nottingham

Scientists in the U.K. have demonstrated a way to trace reserves of brown fat—the body’s “good fat”—using heat-seeking thermal imaging, which could lead to a better understanding of the ongoing obesity epidemic, according to a study published online in the Journal of Pediatrics.

Brown adipose tissue (BAT) produces 300 times more heat than any other tissue in the body, playing a key role in how quickly the body can burn calories as energy, explained study authors Michael E. Symonds, PhD, and colleagues from the University of Nottingham. Having more BAT could potentially mean a person is less likely to store excess energy or food as white fat.

Current methods of assessing BAT activity—PET, SPECT, tissue biopsy—are expensive and require either the exposure to radiopharmaceuticals or tissue sampling. Thermal imaging using an infrared camera, however, is quick and safe, so the authors sought to see whether temperature changes, or thermogenesis, could be reliably detected in the supraclavicular region of the body using the technique. This region was chosen because it is where BAT primarily persists in adults, whereas infants typically have larger amounts of brown fat throughout the body.

The current study used healthy volunteer participants from three age groups: 3-8 (seven participants), 13-18 (12 participants) and 35-58 (seven participants) years of age. Study participants were asked to place one hand in cold water, while the infrared camera measured the body’s response by recording temperature changes in the supraclavicular region.

Within five minutes of the participants placing their hands in the water, thermogenesis was detectable using thermal imaging. The hottest areas seen on thermal imaging corresponded with areas that had previously been established to have higher concentrations of BAT on PET/CT scans. Moreover, when comparing the different study groups, the greatest temperature changes were seen in children and declined through adolescence and into adulthood. The youngest group saw a 0.62° C increase in supraclavicular region temperature, compared with 0.25° C and 0.20° C increases in the 13-18 and 35-58 year old groups, respectively.

“The consistency of baseline thermal activity within the supraclavicular region where BAT is known to be located, in conjunction with the magnitude and rapidity of response, is indicative of a tissue that can be rapidly activated and deactivated,” wrote the authors.

Now that thermogenesis within the supraclavicular region can be reliably quantified using thermal imaging, Symonds and colleagues said the technique could be used to determine the role of thermogenesis in energy balance and obesity prevention.

“This completely non-invasive technique could play a crucial role in our fight against obesity,” Symonds said in a release. “Potentially we could add a thermogenic index to food labels to show whether that product would increase or decrease heat production within brown fat. In other words whether it would speed up or slow down the amount of calories we burn.”