OBJECTIVE: To investigate the effects of a yoghurt containing a novel fat emulsion on energy and macronutrient intakes up to 8 h post-consumption in non-overweight, overweight and obese subjects, and to assess energy compensation over the following 24 h. DESIGN: A double-blind, placebo-controlled, within-subject crossover design was used. Twenty (10 female, 10 male) non-overweight (body mass index (BMI) 20-24.9 kg/m(2)), 20 (10 female, 10 male) overweight (BMI 25-29.9 kg/m(2)) and 20 (13 female, 7 male) obese (BMI>30 kg/m(2)) subjects participated in the study. Subjects were given in random order, 7 days apart, either a 200 g portion of a test (5 g of a novel fat emulsion+1 g milk fat) or control (6 g milk fat) yoghurt at 09:00 h. At 4 and 8 h post-consumption subjects were given ad libitum access to a range of foods. Amounts of food consumed were determined by pre and post-covert weighing of individual serving dishes. Over the following 24 h subjects weighed and recorded all food intakes. RESULTS: Mean energy intakes were significantly lower after the test yoghurt compared with the control yoghurt in non-overweight (3.79 vs 5.43 MJ; P<0.01) and overweight (4.43 vs 6.12 MJ; P<0.001) subjects 4 h post-consumption and in non-overweight (3.82 vs 5.38 MJ; P<0.001), overweight (3.94 vs 5.80 MJ; P<0.001) and obese (4.91 vs 6.26 MJ; P<0.01) subjects 8 h post-consumption. The corresponding macronutrient intakes were also significantly reduced in non-overweight and overweight subjects (P<0.01) at 4 h post-consumption and in all subjects 8 h post-consumption (P<0.01). In the total group, energy intakes over the following 24 h were also significantly reduced (6.35 vs 7.70 MJ; P<0.01) after the test yoghurt relative to the control yoghurt. CONCLUSIONS: These results suggest that the effects of this novel fat emulsion are maintained at least up to 8 h and are evident in non-overweight, overweight and obese subjects.