The least intrusive weight loss methods, and those most often recommended, are adjustments to eating patterns and increased physical activity, generally in the form of exercise. The World Health Organization recommended that people combine a reduction of processed foods high in saturated fats, sugar and salt and caloric content of the diet with an increase in physical activity.
^ On the dates of the Pali canon, Gregory Schopen writes, "We know, and have known for some time, that the Pali canon as we have it — and it is generally conceded to be our oldest source — cannot be taken back further than the last quarter of the first century BCE, the date of the Alu-vihara redaction, the earliest redaction we can have some knowledge of, and that — for a critical history — it can serve, at the very most, only as a source for the Buddhism of this period. But we also know that even this is problematic... In fact, it is not until the time of the commentaries of Buddhaghosa, Dhammapala, and others — that is to say, the fifth to sixth centuries CE — that we can know anything definite about the actual contents of [the Pali] canon."
^ James Mallinson, "Sāktism and Hathayoga," 6 March 2012. PDF file Archived 16 June 2013 at the Wayback Machine [accessed 10 June 2012] pp. 20–21 "The Buddha himself is said to have tried both pressing his tongue to the back of his mouth, in a manner similar to that of the hathayogic khecarīmudrā, and ukkutikappadhāna, a squatting posture which may be related to hathayogic techniques such as mahāmudrā, mahābandha, mahāvedha, mūlabandha, and vajrāsana in which pressure is put on the perineum with the heel, in order to force upwards the breath or Kundalinī."
Similarly, Brahma sutras – the foundational text of the Vedanta school of Hinduism, discusses yoga in its sutra 2.1.3, 2.1.223 and others. Brahma sutras are estimated to have been complete in the surviving form sometime between 450 BCE to 200 CE, and its sutras assert that yoga is a means to gain "subtlety of body" and other powers. The Nyaya sutras – the foundational text of the Nyaya school, variously estimated to have been composed between the 6th-century BCE and 2nd-century CE, discusses yoga in sutras 4.2.38–50. This ancient text of the Nyaya school includes a discussion of yogic ethics, dhyana (meditation), samadhi, and among other things remarks that debate and philosophy is a form of yoga.
One of the earliest and most influential sub-traditions of Vedanta, is Advaita Vedanta, which posits nondualistic monism. This tradition emphasizes Jñāna yoga (yoga of knowledge), which is aimed at realizing the identity of one's atman (soul, individual consciousness) with Brahman (the Absolute consciousness). The most influential thinker of this school is Adi Shankara (8th century), who wrote various commentaries and original works which teach Jñāna yoga. In Advaita Vedanta, Jñāna is attained on the basis of scripture (sruti) and one's guru and through a process of listening (sravana) to teachings, thinking and reflecting on them (manana) and finally meditating on these teachings (nididhyāsana) in order to realize their truth. It is also important to develop qualities such as discrimination (viveka), renunciation (virāga), tranquility, temperance, dispassion, endurance, faith, attention and a longing for knowledge and freedom ('mumukṣutva).' Yoga in Advaita is ultimately a "meditative exercise of withdrawal from the particular and identification with the universal, leading to contemplation of oneself as the most universal, namely, Consciousness".
According to Crangle, some researchers have favoured a linear theory, which attempts "to interpret the origin and early development of Indian contemplative practices as a sequential growth from an Aryan genesis",[note 4] just like traditional Hinduism regards the Vedas to be the ultimate source of all spiritual knowledge.[note 5] Thomas McEvilley favors a composite model where pre-Aryan yoga prototype existed in the pre-Vedic period and its refinement began in the Vedic period.