In this research, we examine the interplay between physiological and psychological factors that determine whether the sugar level of a preload increases or decreases consumption on a subsequent snack-eating task. In study 1, participants who drank a high-sugar protein shake (which they believed to be healthy) consumed more subsequent snacks than participants who drank a low-sugar protein shake.
Study 2 replicated these findings, but only when the shake was labeled as "healthy." When the shake was labeled as "indulgent," the effect was mitigated.