Protein deficiency, sarcopenia and cardiometabolic risk in older urban black Cape Town populations: feasibility studies South Africa is a developing country with an ageing population and increasing prevalence of non-communicable diseases such as type II diabetes, high blood pressure, cardiovascular diseases, obesity etc. South Africa also suffers from a high burden of infectious diseases such as HIV/AIDS and tuberculosis. HIV medications prolong lifespan but HIV infection speeds up the ageing process to the extent that a typical 50-year-old HIV patient would be considered an old person in need of care. Thus many individuals in South Africa are physically 'older' than their biological age. In the elderly muscle becomes smaller and weaker leading to frailty and decreased quality of life. Older people in these communities are at an increases risk of ill health: HIV infection predisposes to the development of metabolic and cardiovascular disease and with ageing there is an increased  prevalence of metabolic and cardiac diseases such as diabetes and heart disease. The elderly also suffer more from metabolic and cardiac diseases such as type 2 diabetes and heart disease.   A good diet can prevent both infectious disease and 'lifestyle' diseases like type 2 diabetes. Good nutrition, especially protein, is also essential to prevent muscle wasting in the elderly. We know that in South African townships people under 65 do not eat enough protein. This problem is likely to be worse in largely poor older black South Africans who  most likely do not eat enough protein. This is due to relatively high costs of protein, typically from animals and diary products. As such, it is likely that ageing muscle decline and frailty will be accelerated in the elderly, resulting in decreased overall health, reduced mobility, increasing disease rates, economic demands on healthcare systems and premature death. Frailty and lifestyle diseases in older black South Africans could be reduced by a healthy diet, especially adequate protein.  As many older black Cape Town inhabitants have multiple health complications they are regularly attending community healthcare clinics. These clinics provide an opportunity for clinicians and other healthcare professionals to provide information on a healthier diet that includes higher levels of protein. However it's very difficult to give advice because we do not know what black older South Africans eat or can afford to eat. Complicating this many older South Africans also provide for their grandchildren and may compromise their own dietary needs to feed grandchildren. Thus, before offering advice to an ageing black urban Cape Town population (aged 65-80), we need to answer several preliminary research questions:  1) What is the feasibility and validity of assessing dietary intake in this population? 2) Are black older South Africans protein deficient? 3) Does a lower protein intake contribute to accelerated ageing and increased frailty and disease? 4) How much can black older individuals afford to spend on food for themselves?  To answer these questions we will employ 2 Xhosa speaking field workers and 1 research assistants to recruit 150 individuals aged 65-80 (male and female) in the Cape Town Township of Khayelitsha over 12 months. We will carry out repeated dietary recall measurements, to assess for reliability and validate against urine measurements that indicate the amount of protein eaten. We will also carry out laboratory based measurements at the University of Cape Town to assess muscle quality, frailty and risk of developing metabolic disease. Finally, we will use recently developed measurement tools to assess the food budget.  Effects of diet and food security is unexplored in older South Africans. It is anticipated that this study will produce extremely useful data to inform on health requirements, nutrition requirements and financial constraints for black older South Africans. These data will also be extremely valuable for larger scale studies to assess the health effectiveness of altering diet in this population. The Global Challenges Research Fund (GCRF) supports cutting-edge research to address challenges faced by developing countries. The fund addresses the UN sustainable development goals. It aims to maximise the impact of research and innovation to improve lives and opportunity in the developing world.