Increased de novo lipogenesis and reduced fatty acid oxidation are probable contributors to adipose accretion in obesity. Moreover, these perturbations have a role in leading to non-alcoholic steatohepatitis, dyslipidemia, and insulin resistance--via "lipotoxicity"-related mechanisms. Research in this area has prompted an effort to evaluate several discrete enzymes in these pathways as targets for future therapeutic intervention. Acetyl-CoA carboxylase 1 (ACC1) and ACC2 regulate fatty acid synthesis and indirectly control fatty acid oxidation via a key product, malonyl CoA. Based on mouse genetic and preclinical pharmacologic evidence, inhibition of ACC1 and/or ACC2 may be a useful approach to treat obesity and metabolic syndrome. Similarly, available data suggest that inhibition of other enzymes in this pathway, including fatty acid synthase, stearoyl CoA desaturase, and diacylglycerol acytransferase 1, will have beneficial effects. AMP-activated protein kinase is a master regulator of nutrient metabolism, which controls several aspects of lipid metabolism. Activation of AMPK in selected tissues is also a potential therapeutic approach. Inhibition of hormone-sensitive lipase is another possible approach. The rationale for modulating the activity of these enzymes and their relative merits (and downsides) as possible therapeutic targets are further discussed.