RecruitingPhase 3Behavioural interventionConfirmation of Diet as a Treatment for Gulf War IllnessThis clinical trial aims to confirm previous findings from a smaller study which demonstrated significant improvements in all symptoms among veterans with Gulf War Illness after one month on the dietary intervention. The main objectives of this study are: 1) to confirm previous findings of treatment response to the diet in a larger and more diverse group; 2) to examine how changes in the nervous system may be the reason for improvement; and 3) to identify markers which change in the blood after one month on the diet. Participants will have baseline measures collected and then will be randomized into the intervention or wait-listed control group, which they will follow for one month before being reassessed.