Weight loss in obese individuals has been shown to improve or prevent many of the aforementioned conditions.Bariatric surgical intervention in patients with adiposity was found not to improve tryptophan breakdown rates and other signs of immune activation and inflammation [4],whereas caloric restriction is known to be a strong activator of protective metabolic pathways, thereby leading to lower blood pressure, improved blood lipids, and reduced inflammatory markers,including CRP [9]. Still, little is known about the effects of an extreme short-term hypocaloric diet on Trp metabolism and changes in inflammatory biomarkers. The present study assessed the effect of a 2-week caloric restriction weight loss diet on Trp breakdown, leptin, and inflammatory biomarkers in overweight adults.