Pre-philosophical speculations of yoga begin to emerge in the texts of c. 500 – c. 200 BCE. Between 200 BCE and 500 CE, philosophical schools of Hinduism, Buddhism, and Jainism were taking form and a coherent philosophical system of yoga began to emerge. The Middle Ages saw the development of many satellite traditions of yoga. Yoga came to the attention of an educated western public in the mid 19th century along with other topics of Indian philosophy.
^ Housman & Dorman 2005, pp. 303–04. "The linear model supported previous findings, including regular exercise, limited alcohol consumption, abstinence from smoking, sleeping 7–8 hours a night, and maintenance of a healthy weight play an important role in promoting longevity and delaying illness and death." Citing Wingard DL, Berkman LF, Brand RJ (1982). "A multivariate analysis of health-related practices: a nine-year mortality follow-up of the Alameda County Study". Am J Epidemiol. 116 (5): 765–75. doi:10.1093/oxfordjournals.aje.a113466. PMID 7148802.
In 2008 between US$33 billion and $55 billion was spent annually in the US on weight-loss products and services, including medical procedures and pharmaceuticals, with weight-loss centers taking between 6 and 12 percent of total annual expenditure. Over $1.6 billion a year was spent on weight-loss supplements. About 70 percent of Americans' dieting attempts are of a self-help nature. https://buzzingofferselfhelp.tumblr.com/