Wall BT, Cruz AM, Otten B, et al. - This study was undertaken to determine if anabolic resistance was correlated with reduced postprandial amino acid uptake or exacerbated by excess lipid availability. For this investigation, 20 men had 7 days of forearm immobilization while consuming a eucaloric (CON; n = 11) or high-fat overfeeding (HFD; n = 9; 50% excess energy as fat) diet (parallel design) within the Nutritional Physiology Research Unit. In either group, immobilization did not affect the forearm muscle aCSA, but tended to reduce the net balance of postabsorptive phenylalanine and leucine in CON and HFD equivalently. Disuse impairs the ability of a protein-rich meal to promote a positive balance of muscle amino acids, which is aggravated by over-supply of dietary lipid. In addition, disuse of reduced postprandial forearm amino acid uptake; however, this does not worsen under high-fat conditions.