Osteosarcopenia (OS), which has become a global public health problem, is a geriatric syndrome in which sarcopenia and osteoporosis co-exist, leading to falls, fractures, and even varying degrees of disability in the elderly. The Dietary Inflammatory Index (DII) is a tool to measure the overall level of dietary inflammation in an individual, and the DII score is closely associated with the development of OS. This article reviews the basic concepts of DII and OS and their interrelationships, focusing on the associations between diet, inflammation, DII and OS, with the aim of providing a reference for dietary interventions in the prevention and control of OS patients.