The origins of yoga are a matter of debate.[44] There is no consensus on its chronology or specific origin other than that yoga developed in ancient India. Suggested origins are the Indus Valley Civilization (3300–1900 BCE)[45] and pre-Vedic Eastern states of India,[46] the Vedic period (1500–500 BCE), and the śramaṇa movement.[47] According to Gavin Flood, continuities may exist between those various traditions:
The hymns in Book 2 of the Shvetashvatara Upanishad, another late first millennium BCE text, states a procedure in which the body is held in upright posture, the breath is restrained and mind is meditatively focussed, preferably inside a cave or a place that is simple, plain, of silence or gently flowing water, with no noises nor harsh winds.[102][103][100]
a technique for entering into other bodies, generating multiple bodies, and the attainment of other supernatural accomplishments; these are, states White, described in Tantric literature of Hinduism and Buddhism, as well as the Buddhist Sāmaññaphalasutta;[41] James Mallinson, however, disagrees and suggests that such fringe practices are far removed from the mainstream Yoga's goal as meditation-driven means to liberation in Indian religions.[42]
^ Gavin Flood: "These renouncer traditions offered a new vision of the human condition which became incorporated, to some degree, into the worldview of the Brahman householder. The ideology of asceticism and renunciation seems, at first, discontinuous with the brahmanical ideology of the affirmation of social obligations and the performance of public and domestic rituals. Indeed, there has been some debate as to whether asceticism and its ideas of retributive action, reincarnation and spiritual liberation, might not have originated outside the orthodox vedic sphere, or even outside Aryan culture: that a divergent historical origin might account for the apparent contradiction within 'Hinduism' between the world affirmation of the householder and the world negation of the renouncer. However, this dichotomization is too simplistic, for continuities can undoubtedly be found between renunciation and vedic Brahmanism, while elements from non-Brahmanical, Sramana traditions also played an important part in the formation of the renunciate ideal. Indeed there are continuities between vedic Brahmanism and Buddhism, and it has been argued that the Buddha sought to return to the ideals of a vedic society which he saw as being eroded in his own day."[49]
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.[23][24]

According to Tattvarthasutra, 2nd century CE Jain text, yoga is the sum of all the activities of mind, speech and body.[6] Umasvati calls yoga the cause of "asrava" or karmic influx[171] as well as one of the essentials—samyak caritra—in the path to liberation.[171] In his Niyamasara, Acarya Kundakunda, describes yoga bhakti—devotion to the path to liberation—as the highest form of devotion.[172] Acarya Haribhadra and Acarya Hemacandra mention the five major vows of ascetics and 12 minor vows of laity under yoga. This has led certain Indologists like Prof. Robert J. Zydenbos to call Jainism, essentially, a system of yogic thinking that grew into a full-fledged religion.[173] The five yamas or the constraints of the Yoga Sutras of Patanjali bear a resemblance to the five major vows of Jainism, indicating a history of strong cross-fertilization between these traditions.[173][note 16]
Vajrayana is also known as Tantric Buddhism and Tantrayāna. Its texts were compiled starting with 7th century and Tibetan translations were completed in 8th century CE. These tantra yoga texts were the main source of Buddhist knowledge that was imported into Tibet.[185] They were later translated into Chinese and other Asian languages, helping spread ideas of Tantric Buddhism. The Buddhist text Hevajra Tantra and Caryāgiti introduced hierarchies of chakras.[186] Yoga is a significant practice in Tantric Buddhism.[187][188][189]

Virtual gastric band uses hypnosis to make the brain think the stomach is smaller than it really is and hence lower the amount of food ingested. This brings as a consequence weight reduction. This method is complemented with psychological treatment for anxiety management and with hypnopedia. Research has been conducted into the use of hypnosis as a weight management alternative.[16][17][18][19] In 1996 a study found that cognitive-behavioral therapy (CBT) was more effective for weight reduction if reinforced with hypnosis.[17] Acceptance and Commitment Therapy ACT, a mindfulness approach to weight loss, has also in the last few years been demonstrating its usefulness.[20]
Unintentional weight loss may result from loss of body fats, loss of body fluids, muscle atrophy, or even a combination of these.[25][26] It is generally regarded as a medical problem when at least 10% of a person's body weight has been lost in six months[25][27] or 5% in the last month.[28] Another criterion used for assessing weight that is too low is the body mass index (BMI).[29] However, even lesser amounts of weight loss can be a cause for serious concern in a frail elderly person.[30]
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]