Dietary interventions with n-3 fatty acids such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) can ameliorate various obesity-associated pathologies including insulin resistance. This presentation will focus on our recent studies in obese mice, which suggested a higher efficiency of EPA+DHA administered as marine phospholipids to improve glucose tolerance and insulin sensitivity when compared with traditional fish oil. Changes in the systemic and tissue levels of endocannabinoids in response to EPA+DHA administration and their potential role in beneficial metabolic effects of n-3 fatty acids will be also discussed.