Excessive exposure of tissues to fatty acids is likely to be the chief cause of the various dysfunctions that lead to sustained hyperglycemia in type II diabetes. These dysfunctions are likely to be substantially reversible if body fat and dietary fat can be greatly reduced. Disinhibition of hepatic fatty acid oxidation with hydroxycitrate (HCA) and carnitine has considerable potential as a new weight-loss strategy, but in diabetics runs the risk of further enhancing excessive hepatic gluconeogenesis. Since the clinical utility of metformin in diabetes is probably traceable to inhibition of gluconeogenesis, its use as an adjunct to HCA/carnitine treatment of obesity in diabetics deserves evaluation, particularly as metformin therapy itself tends to reduce body weight. A consideration of relevant evidence suggests that metformin therapy will not impede the activation of fatty acid oxidation by HCA/carnitine, and is likely to potentiate the appetite-suppressant and thermogenic benefits of this strategy. Indeed, since metformin has been reported to lower body weight and improve cardiovascular risk factors in obese non-diabetics, a broader application of a metformin/HCA/carnitine therapy for obesity can be contemplated.