Central to the interpretation of the results of the PREDIMED trial is an understanding of achieved dietary changes. Despite advice to lower fat intake and limit consumption of olive oil and nuts, the control group did not achieve a low fat intake. Indeed, the control group appeared to consume a variant of the Mediterranean diet. At the end of the trial, total fat was 37% of energy intake in the control group and 41% of energy intake in the other two groups; saturated-fat intake was low and similar in the three groups, approximately 9% of energy intake. In the group receiving extra-virgin olive oil, the additional 4 percentage points in energy intake from fat resulted mostly from increased monounsaturated-fat intake. In the group receiving mixed nuts, the additional 4 percentage points resulted from increases of approximately 2 percentage points in both monounsaturated and polyunsaturated fat.
