We fed managed honey bee colonies one of two commercially available pollen substitutes (MegaBee, AP23) or no diet over late fall and winter in Florida, U.S.A. We measured the change in mass of adult bees, brood, and full colonies after nine weeks of feeding. We also measured the average mass per pupa, amount of pollen substitute patty consumed, the average total mass of natural pollen collected, and the proportion of pollen foragers.