Background: Reduced-energy-dense diet foods are often formulated to match the sensory characteristics of their regular-energy-dense counterparts. However, the extent to which attitudes toward a reduced-energy-dense food remain constant, even after repeated ingestion, remains to be explored systematically.
Objective: The objective was to determine whether liking, "expected satiety," and "expected satiation" change after repeated exposure to a familiar food that has been reduced in energy density. Expected satiety and expected satiation refer to the extent to which foods are expected to stave off hunger and to deliver "fullness," respectively, when compared on a calorie-for-calorie basis.
Design: Participants (n = 36) consumed either reduced-energy-dense (374 kcal) or standard-energy-dense (567 kcal) spaghetti Bolognese for lunch over 5 test sessions. During each test session, liking for the spaghetti Bolognese was assessed, together with measures of expected satiety and expected satiation.
Results: Participants in the reduced-energy-dense condition reported a decrease in liking for the spaghetti Bolognese over the test sessions ( approximately 30%), whereas liking in the standard condition remained constant [condition (reduced/standard) x session (1-5) interaction, P < 0.008]. By contrast, both expected satiation and expected satiety remained similar across conditions and test sessions.
Conclusions: Over time, the pleasantness of a reformulated low-energy-dense food can decrease, and this may undermine its efficacy as a weight-loss product. It remains to be determined whether a longer period of "flavor-nutrient learning" is needed for shifts in expected satiety and expected satiation to be observed.