Objective: To investigate the dose-response effects of a novel fat emulsion (Olibra(TM)) on energy and macronutrient intakes up to 36 h post-consumption in non-overweight subjects. Design: A single-blind, placebo-controlled, within-subject cross-over design was used. Setting: Metabolic suite of the University of Ulster, Coleraine. Subjects: Fifty subjects (30 female, 20 mate) from the student and staff population of the University of Ulster, Coleraine. Interventions: Subjects were given in random order, 7 days apart, a 200 g portion of yoghurt containing a total of 15 g of fat, which varied in quantity of Olibra(TM) fat (0, 2, 4, 6 g) at 09:00 h. At 13:00 h subjects were given ad libitum access to a range of foods. Amounts of food consumed were measured by covert pre- and post-consumption weighing of individual serving dishes. For the remainder of the day and the following 24 h, subjects weighed and recorded all food intakes. Results: Relative to the control yoghurt, mean energy (7.42 vs 5.83, 5,60, 5.24 MJ), fat (97.4 vs 74.4, 74.2, 67.5 g; 48.8 vs 46.8, 48.9, 47.6% energy), protein (59.1 vs 50.0, 44.0, 40.8 g; 13.2 vs 13.9, 12.9, 12.8% energy), and carbohydrate (171.5 vs 140.9, 130.2, 126.0 g; 38.0 vs 39.3, 38.2, 39.6% energy), intakes were progressively reduced with increasing doses of Olibra(TM) fat in the total group (P < 0.001). A similar response was observed in the female group up to 4 g (P < 0.001) and in the male group after 2 and 6 g (P < 0.05). Energy and macronutrient intakes for the remainder of each study day and over the following 24 h were significantly lower after all dose levels compared to the control (P < 0.001). Conclusion: The results suggest that Olibra(TM) fat reduced the effect of overeating during an ad libitum lunch meal and subsequent food intake up to 36 h post-consumption. Sponsorship: Scotia Pharmaceuticals Limited.