Increased availability of lipids may conserve muscle protein during catabolic stress. Our study was designed to define (i) intracellular mechanisms leading to increased lipolysis and (ii) whether this scenario is associated with decreased amino acid and urea fluxes and decreased muscle amino acid release in obese subjects under basal and fasting conditions. We therefore studied 9 lean and 9 obese subjects twice, after 12 and 72 h of fasting, using measurements of mRNA and protein expression and phosphorylation of lipolytic and protein metabolic signaling molecules in fat and muscle together with whole body and forearm tracer techniques. Obese subjects displayed increased whole body lipolysis, decreased urea production rates and decreased forearm muscle protein breakdown per 100 ml forearm, differences which persisted after 72-h of fasting. Lipolysis per fat mass unit was reduced in obese subjects and correspondingly, adipose tissue HSL phosphorylations and mRNA and protein levels of the ATGL coactivator CGI58 were decreased. Fasting increased HSL phosphorylations and decreased protein levels of the ATGL inhibitor G0S2. Muscle protein expressions of mTOR and 4EBP1 were decreased in obese subjects and MuRf1 mRNA increased with fasting in lean but not obese subjects. mTOR phosphorylation and signaling decreased with fasting in both groups, while ULK1 protein and mRNA levels increased. In summary obese subjects exhibit increased lipolysis, due to a large fat mass with blunted pro-lipolytic signaling, together with decreased urea and amino acid fluxes both in the basal and 72h-fasted state; this is compatible with preservation of muscle and whole body protein.