1. Weight loss will be induced by bariatric surgery (bypass) in very obese subjects (BMI > 40). S-CD163 and changes in insulin sensitivity (HOMA) and other inflammatory markers (e.g. hsCRP, IL-6, TNF, MCP-1, adiponectin etc.) will be measured before and after 6 and 12 months after surgery. From power calculations it is planned to include 45 very obese subjects in this study - half of them with type 2 diabetes.