Diet Interventions in Psoriatic Arthritis

The purpose of this study is to learn whether changing diet impacts psoriatic arthritis (PsA).

Inclusion Criteria: * Age 18-80 * Required Rheumatologist-confirmed diagnosis of PsA fulfilling Classification of Psoriatic Arthritis Criteria (CASPAR) * Willing to alter diet and participate for 24 weeks * Able to attend follow-up visits * Body mass index (BMI) \> 25 and \ 10 * Stable treatment for PsA for ≥3 months prior to enrollment (patients may be on any disease modifying anti-rheumatic drugs (DMARDs) or they can be free of systemic medications * Owns and uses an iPhone or Android smart phone, or is willing to use a device provided by the study team Exclusion Criteria: * Inability to provide informed consent * Plan to change systemic treatment for psoriasis or PsA in the next 4-8 weeks * Use of systemic corticosteroids * All persons who would be placed at an increased risk including any medical condition that will impair the ability of the person to participate in a nutritional intervention study (e.g. insulin dependent diabetes, use of coumadin, advanced malignancy, inflammatory bowel disease, dementia) * History of food allergy to any of the components of olive oil or nuts * Inability to read and write in English * Unwillingness to change dietary habits * Known pregnancy (pregnancy testing will be performed for women of childbearing age; weight changes will not accurately reflect the changes we would anticipate in pregnant patients and weight loss may be detrimental to maternal and/or fetal outcomes). * Participation in another physical activity study and/or diet trial