The influence of fasting and of caffeine intake on finger tremor.

The effect of finger tremor of the administration of 150 mg of caffeine three times daily for two days was measured using an accelerometer in 7 healthy subjects taking their normal diet (excluding caffeine-containing beverages). The effect on finger tremor of a short period of fasting with and without the 450 mg daily dose of caffeine was also studied in the same 7 subjects. Fasting increased finger tremor significantly when caffeine was administered. In doses comparable to the likely adult daily intake in this country, caffeine did not increase finger tremor whilst subjects were taking their normal diet.