Many patients will be in pain and have a loss of appetite after surgery.[25] Part of the body's response to surgery is to direct energy to wound healing, which increases the body's overall energy requirements.[25] Surgery affects nutritional status indirectly, particularly during the recovery period, as it can interfere with wound healing and other aspects of recovery.[25][29] Surgery directly affects nutritional status if a procedure permanently alters the digestive system.[25] Enteral nutrition (tube feeding) is often needed.[25] However a policy of 'nil by mouth' for all gastrointestinal surgery has not been shown to benefit, with some suggestion it might hinder recovery.[37][needs update]
Various yogic groups had become prominent in Punjab in the 15th and 16th century, when Sikhism was in its nascent stage. Compositions of Guru Nanak, the founder of Sikhism, describe many dialogues he had with Jogis, a Hindu community which practiced yoga. Guru Nanak rejected the austerities, rites and rituals connected with Hatha Yoga. He propounded the path of Sahaja yoga or Nama yoga (meditation on the name) instead.[201] The Guru Granth Sahib states:
A yoga system that predated the Buddhist school is Jain yoga. But since Jain sources postdate Buddhist ones, it is difficult to distinguish between the nature of the early Jain school and elements derived from other schools.[89] Most of the other contemporary yoga systems alluded in the Upanishads and some Buddhist texts are lost to time.[90][91][note 12]
^ James Mallinson, "Sāktism and Hathayoga," 28 June 2012. Archived 16 June 2013 at the Wayback Machine [accessed 19 September 2013] pgs. 2 "In its earliest definition, in Pundarīka's eleventh-century Vimalaprabhā commentary on the Kālacakratantra, hathayoga is said to bring about the "unchanging moment" (aksaraksana) "through the practice of nāda by forcefully making the breath enter the central channel and through restraining the bindu of the bodhicitta in the vajra of the lotus of wisdom". While the means employed are not specified, the ends, in particular restraining bindu, semen, and making the breath enter the central channel, are similar to those mentioned in the earliest descriptions of the practices of hathayoga, to which I now turn."
The origins of yoga have been speculated to date back to pre-Vedic Indian traditions; it is mentioned in the Rigveda,[note 1] but most likely developed around the sixth and fifth centuries BCE,[8] in ancient India's ascetic and śramaṇa movements.[9][note 2] The chronology of earliest texts describing yoga-practices is unclear, varyingly credited to Upanishads.[10] The Yoga Sutras of Patanjali date from the first half of the 1st millennium CE,[11][12] but only gained prominence in the West in the 20th century.[13] Hatha yoga texts emerged around the 11th century with origins in tantra.[14][15]
Just as there was a shift from viewing disease as a state to thinking of it as a process, the same shift happened in definitions of health. Again, the WHO played a leading role when it fostered the development of the health promotion movement in the 1980s. This brought in a new conception of health, not as a state, but in dynamic terms of resiliency, in other words, as "a resource for living". 1984 WHO revised the definition of health defined it as "the extent to which an individual or group is able to realize aspirations and satisfy needs and to change or cope with the environment. Health is a resource for everyday life, not the objective of living; it is a positive concept, emphasizing social and personal resources, as well as physical capacities".[10] Thus, health referred to the ability to maintain homeostasis and recover from insults. Mental, intellectual, emotional and social health referred to a person's ability to handle stress, to acquire skills, to maintain relationships, all of which form resources for resiliency and independent living.[9] This opens up many possibilities for health to be taught, strengthened and learned.
Some popular beliefs attached to weight loss have been shown to either have less effect on weight loss than commonly believed or are actively unhealthy. According to Harvard Health, the idea of metabolism being the "key to weight" is "part truth and part myth" as while metabolism does affect weight loss, external forces such as diet and exercise have an equal effect.[43] They also commented that the idea of changing one's rate of metabolism is under debate.[43] Diet plans in fitness magazines are also often believed to be effective, but may actually be harmful by limiting the daily intake of important calories and nutrients which can be detrimental depending on the person and are even capable of driving individuals away from weight loss.[44]

The Bhakti movement was a development in medieval Hinduism which advocated the concept of a personal God (or "Supreme Personality of Godhead"). The movement was initiated by the Alvars of South India in the 6th to 9th centuries, and it started gaining influence throughout India by the 12th to 15th centuries.[177] Shaiva and Vaishnava bhakti traditions integrated aspects of Yoga Sutras, such as the practical meditative exercises, with devotion.[178] Bhagavata Purana elucidates the practice of a form of yoga called viraha (separation) bhakti. Viraha bhakti emphasizes one pointed concentration on Krishna.[179]

Sleep is an essential component to maintaining health. In children, sleep is also vital for growth and development. Ongoing sleep deprivation has been linked to an increased risk for some chronic health problems. In addition, sleep deprivation has been shown to correlate with both increased susceptibility to illness and slower recovery times from illness.[47] In one study, people with chronic insufficient sleep, set as six hours of sleep a night or less, were found to be four times more likely to catch a cold compared to those who reported sleeping for seven hours or more a night.[48] Due to the role of sleep in regulating metabolism, insufficient sleep may also play a role in weight gain or, conversely, in impeding weight loss.[49] Additionally, in 2007, the International Agency for Research on Cancer, which is the cancer research agency for the World Health Organization, declared that "shiftwork that involves circadian disruption is probably carcinogenic to humans," speaking to the dangers of long-term nighttime work due to its intrusion on sleep.[50] In 2015, the National Sleep Foundation released updated recommendations for sleep duration requirements based on age and concluded that "Individuals who habitually sleep outside the normal range may be exhibiting signs or symptoms of serious health problems or, if done volitionally, may be compromising their health and well-being."[51]