It is well accepted that nutrition as an environmental factor is involved in the pathogenesis of multiple sclerosis. But is there a role for prolonged fasting and ketogenic low glycemic load treatment to alter the course of multiple sclerosis (MS)? The investigators think yes there is. Primarily the investigators want to detect if these diets are feasible for MS patients. Therefore the investigators examine the impact of this dietary intervention on the health related quality of life for individuals after 7 days, 3 months and 6 months in compare to baseline. Secondarily the investigators focus on endocrinological and immunological changes after 7 days, 3 months and 6 months in compare to baseline.

In this controlled randomised pilot study the patients are allocated to 1. a ketogenic low glycemic load treatment from the outset of the study for 24 weeks or 2. enhance their regular diet with an initial 7-day fasting followed by a Mediterranean diet pattern until the study end or 3. stay on their regular diet (control group) from the outset of the study for 24 weeks. The investigators will then assess the differences between the groups.

Inclusion Criteria:

• Relapsing remitting MS
• Stable immunomodulatory treatment or no treatment at least 6 months prior to inclusion
• Expanded disability status scale < 7
• Body mass index (BMI) > or = 18,5 OR BMI > or = 45 with no risk factors
• Not pregnant or breast-feeding
• No serious mental health illness such as dementia or schizophrenia;
• No use of a weight loss therapy in the month prior to screening.

Exclusion Criteria:

• Start or changes if immunomodulatory treatment < 7 months prior to screening
• SPMS or PPMS
• Relapse or corticosteroid use < 30 days prior to screening
• Diabetes or any metabolic defects
• Bulimia
• Anorexia
• Drug abuse