Though the idea of using the IGT in obesity research is not new, the ARS investigation is the first to show, in what scientists refer to as a controlled-feeding weight-loss trial, an association between IGT scores and diet-induced weight loss.
Cortisol findings were based on concentrations of the hormone in saliva samples collected throughout the day on two different test dates. The scientists found that volunteers' cortisol concentrations generally increased from the beginning to the end of the 12 weeks of dieting.
Laugero noted that increases in cortisol concentration have long been regarded as a reliable indicator of psychological stress, and that stress is considered to be a contributing factor to dieters' relapsing back to old eating habits and regaining weight.