The effect of levodopa with carbidopa (Sinemet R) on the metabolic response to semistarvation

It has been reported that levodopa will prevent the adaptive fall in the resting metabolic rate (RMR) on a weight-reducing diet. Whether levodopa has a central or peripheral effect on the RMR has been investigated by giving carbidopa, a peripheral dopa decorboxylase inhibitor with levodopa (as SinemetR) to four obese subjects on a low-energy diet. SinemetR failed to prevent the adaptive reduction in the RMR to energy restriction suggesting that levodopa maintains the RMR by a peripheral effect or effects.