During this 23-day study, a wide selection of food items and beverages were freely available. During this double-blind, within-participant study, volunteers (N=11) received oral Provigil dose (0, 200, or 400 mg) 1 h after waking for three consecutive days under two shift conditions: day shift and night shift. Shifts alternated three times during the study, and shift conditions were separated by an “off” day.
Provigil (200, 400 mg) dose-dependently decreased total caloric intake by ~18% and ~38%, respectively, regardless of shift condition, without selectively altering the proportion of total calories derived from carbohydrate, fat and protein. Ratings of “Hungry” were also significantly decreased by both active doses, but only immediately before the lunch break period.
In addition, tolerance to the anorexic effects of Provigil was not apparent, as these effects remained stable across the three days of Provigil dosing. These findings show that Provigil produced clear reductions in food intake and suggest that future prospective studies should examine the drug in obese participants.