Recent studies have revealed that autistic spectrum disorders (ASD) is associated with enhanced glycolysis (i.e. establishment of the Warburg effect) accompanied by increased formation of glycated proteins in sera and urine. Both carnosine and agmatine levels in sera of autistic individuals are reported to be lower than in control subjects. Carnosine and agmatine can influence cellular energy metabolism, in part via effects on mTOR, thereby decreasing glycolysis and enhancing mitochondrial activity and thus countering onset of Warburg-like metabolism: other mechanisms including suppressing methylglyoxal toxicity are also discussed. Dietary supplementation studies with carnosine and arginine (agmatine precursor) indicate ameliorative activity towards behaviour in ASD subjects. It is suggested that co-administration of carnosine and agmatine should be explored as a potential route for ASD amelioration.