The World Health Organization defined “health” simply as the physical, social, and mental well-being of humanity, in which “health” was widened beyond those biomedical aspects (e.g., disease and illness) to encompass the socioeconomic and psychological domains. This classical definition advocated health’s shift toward a holistic perspective, with emphasis on more positive attributes and was not simply “the mere absence of disease and infirmity” . It also reflected people’s ambitious outlook after the Second World War, when health and peace were seen as inseparable. Since then, this shift has seen a major growth in the last 30 years, primarily in areas of positive health and psychology.

Despite its broad perspective of human health, the definition has also encountered criticism in relation to its description and its overall reflectance of modern society. For instance, the use of the term “completeness” when describing optimal health has been regarded by many as impractical. Instead, Huber et al propose health to be the “ability to adapt and to self-manage” and invite the continuation of further discussions and proposals of this definition to be characterized as well as measured through its three interrelated dimensions; physical, mental, and social health. Similarly, others have highlighted the need to distinguish health from happiness or its inability to fully reflect modern transformations in knowledge and development (e.g., technology, medicine, genomics as well as physical and social environments). As such, there have been calls to reconceptualize this definition, to ensure further clarity and relevance for our adaptive societies.

Research paper:
The Human–Nature Relationship and Its Impact on Health: A Critical Review
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5114301/#S2-1