Introduction: Overweight and obesity may result in part from an increased intake of high fat foods. The aim of this study was to investigate the affect of different fatty acid containing meals on appetite parameters.

Methods: Nine normoglycaemic overweight or obese individuals (BMI 32 ± 1.2 kg/m²) randomly completed 4 weekly, single-blinded, fasting breakfast challenges. Meals consisted of toasted bread, jam and varying oils, resulting in control, and high lauric, oleic and linoleic acid meals. All meals provided 30% of EER. Appetite parameters were assessed immediately before consumption and 2 hours postprandially with visual analogue scale questionnaires.

Results: All meals resulted in decreased hunger and increased fullness, though appetite responses did not differ between meals. The lauric and linoleic acid meals decreased postprandial desire to eat. The linoleic and oleic acid meals did not decrease postprandial prospective food intake, whereas the control and lauric acid meals did.

Discussion: Each lauric acid meal contained on average 14g of lauric acid, which has been found to dose- dependently decrease gastric emptying, a likely cause of the postprandial increase in perception of fullness, and decrease in perception of hunger, desire to eat, and prospective food intake. This effect on appetite has been found to be greater than that of oleic acid at the same loading, in line with the findings of this study. Oleic acid may not have affected postprandial desire to eat and prospective food intake possibly due to its decreased ability to modulate appetite in the obese state. Current Australian diets are rich in high-linoleic acid plant-derived fats. Intriguingly, the high linoleic acid meal did not decrease postprandial prospective food intake, which may increase energy consumption at the subsequent meal, influencing obesity risk. The effect of different fatty acids on appetite in obese individuals requires further investigation.