Recent studies have found that up to 45 % of patients with type 1 diabetes have metabolic syndrome, a cluster of conditions (abdominal obesity, hypertension, dyslipidemia, insulin resistance) that increase the cardiovascular risk. The investigators have observed in previous studies a strong association between the adherence to a Mediterranean diet and the prevalence of metabolic syndrome on patients with metabolic syndrome. However, no intervention has been realized on this population and the current recommendations (low fat diet) differ from the Mediterranean diet. A nutritional intervention on the principles of the Mediterranean diet could therefore play a role in the treatment of the metabolic syndrome in Type 1 diabetes patients. The main objective of this study is to examine the impact of a nutritional intervention on the waist circumference after 6 months of an intervention group (Mediterranean diet) versus a control group (low fat diet).