Source
School of Human Kinetics, University of Ottawa, Ontario, Canada.
Abstract
OBJECTIVE:
To examine the effects of methylphenidate hydrochloride (MPH) on resting energy expenditure (REE) and postprandial energy expenditure (PEE) and substrate partitioning.
METHODS AND PROCEDURES:
Seven healthy men and seven healthy women participated in this double-blind, randomized, placebo-controlled, crossover study. MPH (0.5 mg/kg) or placebo was administered orally in the fasting state, 60 min before a REE measurement, and 90 min before a standardized breakfast of approximately 650 kcal. REE, PEE, and respiratory exchange ratio (RER) were obtained from indirect calorimetry. Body composition was measured using DEXA. Vital signs (blood pressure (BP) and heart rate (HR)) were assessed pre- and post-administration of MPH or placebo in every session.
RESULTS:
During the, MPH condition, REE increased over values observed during the placebo session (7%, P < 0.001). No changes in fasting RER were noted. Although PEE continually decreased with time as expected, MPH treatment resulted in significantly greater PEE values at 90 min (5%, P < 0.01). No significant effects of MPH were found for vital signs (HR, systolic, and diastolic BP).
DISCUSSION:
MPH causes a significant increase in both REE and PEE without the significant changes in HR and BP that are commonly associated with psychostimulant use.