This is a research study into the effects of three drugs used to treat HIV infection. Some drugs used to treat HIV have been associated with changes in blood fats such as cholesterol that could be harmful over the long-term, because these blood fat changes have been associated with a small, increased risk of heart disease and stroke in some studies of adults with HIV. Now that HIV can be controlled for long periods in most patients, and because heart disease is one of the biggest causes of illness and death in the general population, it is important to develop new HIV treatments that control HIV effectively but do not cause abnormal blood fats.

Hypothesis: That Raltegravir will result in less post-prandial lipid disturbances than ritonavir-boosted darunavir.

Inclusion Criteria:

• Provision of signed, informed consent
• Age >18 years
• HIV infection documented by HIV antibody test and Western Blot prior to study entry
• No previous ART OR no ART for 6 months prior to randomisation
• CD4+ count of <500 cells/mm or viral load >10,000 copies/ml within 60 days prior to randomisation
• No genotypic resistance to Raltegravir, Tenofovir/emtricitabine, Darunavir, Ritonavir
• Body mass index less than 30kg/m2

Exclusion Criteria:

• Primary HIV infection within the last 6 months
• Active infection or opportunistic illness within the previous 30 days
• Use of any medication contra-indicated with ritonavir-boosted darunavir or raltegravir
• Use of lipid-lowering therapy
• Diabetes mellitus (fasting glucose >7.0mml/l or a prior diagnosis of diabetes)
• Use of oral prednisolone > 7.5mg daily or equivalent
• pregnancy or Breast feeding
• proven hypersensitivity to one or more components of the study meal