Diet and exercise both influence resting energy and fat metabolism; however, the interaction effects between diet and exercise are less elucidated. In the recovery period after exercise there is a shift in substrate utilization from carbohydrate to fat. In addition there is an elevated rate of triglyceride/fatty acid cycling. These processes can contribute substantially to the prolonged component of the excess post-exercise oxygen consumption (EPOC) after exhaustive submaximal exercise, thereby enhancing the direct effects of exercise on caloric expenditure and other metabolic adaptations. The magnitude of change in fat metabolism is known to be related to the duration and intensity of exercise, and also to training status, adiposity and gender. In contrast, there are few studies of the effect of diet on post-exercise fat oxidation, but it is proposed that the amount of fat in the diet may influence EPOC size. Recent findings suggest that diets varying in palmitic acid (PA) and oleic acid (OA) content may affect post-exercise energy expenditure and fat oxidation differently. A diet high in PA appears to diminish EPOC after prolonged submaximal exercise compared to a diet high in OA (Mediterranean style). A better understanding of how diet modulates the effects of exercise on EPOC and fat metabolism is needed in order to optimize the adaptations to exercise.