Tracer energy expenditure

Another goal of the USDA study was to determine whether CLA enhanced energy expenditure, lipolysis, or fat oxidation in humans, similar to the effects observed in animals. Accordingly, measurements of metabolic rate and respiratory quotient were made by indirect calorimetry, and stable isotope tracers of palmitate and glycerol were used to measure the rate of appearance of free fatty acids and glycerol as well as whole body lipolysis and apparent reesterification. CLA supplementation had no effect on metabolic rate or whole-body fat oxidation rate during rest or exercise. Similarly, CLA did not change lipolytic rate, fatty acid release from adipose tissue, or apparent FFA reesterification rates under conditions of rest or exercise (33). 

The C-bicarbonate tracer ( C-BT) technique for estimation of CO2 production and energy expenditure in dogs during rest and physical activity... 

Junghans, R, W. Jentsch and M. Demo, 2008. Non-invasive bicarbonate tracer technique for measuring energy expenditure in men - apilot study. E-SPEN, the European e-joumal of Clinical Nutrition and Metabolism 3, e46-e51. 

---