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Abstract

Although yoga may help manage conditions comorbid with overweight and obesity, such as low back pain, whether yoga helps with weight loss or maintenance beyond that which can be achieved with diet and exercise remains unclear. A search of multiple databases through September 2012 was undertaken identifying peer-reviewed studies on yoga, meditation, mindfulness, obesity, and overweight. Studies on yoga and weight loss are challenged by small sample sizes, short durations, and lack of control groups. In addition, there is little consistency in terms of duration of formal group yoga practice sessions, duration of informal practices at home, and frequency of both. Studies do however suggest that yoga may be associated with weight loss or maintenance. Mechanisms by which yoga may assist with weight loss or maintenance include the following: (a) energy expenditure during yoga sessions; (b) allowing for additional exercise outside yoga sessions by reducing back and joint pain; (c) heightening mindfulness, improving mood, and reducing stress, which may help reduce food intake; and (d) allowing individuals to feel more connected to their bodies, leading to enhanced awareness of satiety and the discomfort of overeating. Thus, yoga appears promising as a way to assist with behavioral change, weight loss, and maintenance.

Keywords

yoga overweight obesity weight loss neuropsychology

‘Although the practice of yoga may help overweight or obese individuals manage comorbid conditions . . . whether it helps with weight loss . . . remains unclear.’

Yoga is one of the most popular types of complementary and alternative medicine (CAM) practiced in the United States and is used far more often than any other type of CAM for weight loss or maintenance.¹ In 2007, 6% of adults reported practicing yoga, an increase of nearly 20% from 5 years earlier.² This rise in popularity might be expected given that more than 50 conditions are reported to benefit from regular practice.³ Overweight or obese individuals are less likely to practice yoga than those who are normal-weight,⁴ yet 40% of yoga practitioners are overweight or obese.⁵

Yoga is a mind–body, or meditative movement, practice originating in ancient India that combines physical postures (asanas), breathing exercises (pranayamas), and meditation or relaxation.⁶ The most common form practiced in the United States is Hatha yoga, which includes the yoga styles Ananda, Anusara, Ashtanga, Bikram, Iyengar, Kripalu, Kundalini, and Viniyoga.⁶ These styles chiefly differ in the intensity of physical activity and strength training and in the emphasis placed on postures, breathing, and meditation.⁷ A typical yoga session is a group class lasting 60 to 90 minutes led by an experienced teacher.⁸ The session begins with a short period of meditation or relaxation (5-20 minutes), followed by a series of postures designed to build flexibility and strength (30-60 minutes), and concluding with a period of rest used to create deep physical and mental relaxation (5-30 minutes).⁸ Individuals can practice each step of the session at home. Throughout the session, there is a focus on breathing with an aim to stimulate mental focus and body awareness.

Although the practice of yoga may help overweight or obese individuals manage comorbid conditions, such as low back pain,^9,10 whether it helps with weight loss or maintenance beyond that which can be achieved with a calorie-reduced diet and increased exercise remains unclear. The purpose of this review was to summarize the evidence on yoga’s relation to weight loss and maintenance, paying particular attention to its impact on behavior, neuropsychology, metabolism, and inflammation. The review then provides the basis for recommendations on yoga practice in the management of weight loss and maintenance.

Methods

We searched for English language, peer-reviewed articles in PubMed and the Cochrane Collaboration database through September 2012 using key words in titles and abstracts such as yoga, meditation, mindfulness, obesity, and overweight. We reviewed references of identified articles to identify additional relevant articles and searched for articles written by authors known to have written extensively in the field of interest. Systematic reviews, meta-analyses, randomized controlled trials, clinical trials, and prospective cohort studies were included.

Results

Weight Loss and Management of Comorbid Conditions

There is a large body of evidence relating yoga to management of chronic conditions associated with overweight and obesity. Much of this research has been conducted by Indian investigators and published in Indian journals.¹¹ Yoga improves back^9,10,12-15 and joint¹⁶ pain; depression^17-22 and stress/anxiety^21,23; and insulin resistance, hypertension, and dyslipidemia.^24-28 It also improves musculoskeletal flexibility.^29,30 Limited data suggest that yoga may improve coronary artery disease and its risk factors by lowering blood pressure, increasing absolute and relative oxygen uptake, improving heart rate variability, decreasing sympathetic tone and baroreflex sensitivity, and slowing atherosclerosis.^28,31 Yoga does not appear to help with asthma³² or diabetes,³³ both of which may develop or worsen in the setting of excess body weight. Limited data prevent any conclusions to be drawn regarding effectiveness of yoga in pediatric populations.^34,35

In contrast to data on comorbid conditions, data are more limited with regard to weight reduction and maintenance. One cross-sectional analysis reported that a greater number of hours of yoga practice over one’s lifetime were associated with a small but significantly lower body mass index (BMI) among middle-aged women (mean BMI of 24 for 1-2500 lifetime hours vs BMI of 20 for more than 15 000 hours), after adjusting for consumption of processed food and weekly exercise.³⁶ One prospective study observed that yoga practice (at least 30 minutes once per week) for 4 or more years was associated with a 3 lb lower weight gain among normal weight (BMI < 25) participants (9.5 lb vs 12.6 lb) and an 18 lb lower weight gain among overweight participants (−5.0 lb vs 13.5 lb; P for trend < .001 for both) even after accounting for diet and physical activity; among overweight individuals, 4 or more years of yoga practice was associated with a relative odds of 1.85 (95% confidence interval [CI] = 0.63-5.42) for weight maintenance (within 5%) and 3.88 (95% CI = 1.30-9.88) for weight loss (>5%) compared to weight gain (P for trend .03 and <.01, respectively).⁸ In a randomized controlled trial of postmenopausal women, 16 weeks of yoga, compared to no exercise, led to decreases in body weight (3.9 kg), percent body fat (3.1 %), BMI (1.7 units), and waist circumference (1.7 cm).³⁷ Sixty patients with type 2 diabetes had a 2 kg decrease in weight after practicing yoga for 45 minutes each day for 45 days when compared to those who did not practice at all.³⁸

Several randomized controlled trials of patients with coronary heart disease have shown that participation in a lifestyle modification program (including, for instance, a low-fat vegetarian diet, stress management, exercise, and smoking cessation) with yoga leads to reduction in body weight, as well as of regression in atherosclerosis at 1 and 5 years.^31,39-41 BMI decreased from a baseline of 32 to a BMI of 30, 30, and 31 at 4, 12, and 24 months, respectively in 28 women randomized to a comprehensive lifestyle modification program with yoga.⁴² Two single-arm intervention studies, one of which included a vegetarian diet, both approximately 1 week in duration with 3 to 5 hours per day of yoga, reported small but significant decreases in BMI (0.4-0.5 units) or weight (0.6 lb).^43,44 After 3 months of yoga and meditation in a single-arm study, there was a significant decrease in waist circumference (5 cm) among obese adults,⁴⁵ and while overweight and obese breast cancer survivors randomized to 6 months of yoga, versus waitlist control, experienced no weight change, they too had a decrease in waist circumference (3.1 cm [95% CI = −5.7 and −0.4]).⁴⁶ This change may indicate a gain in lean muscle mass and loss of abdominal fat. Four months of supervised stretching and yoga for 16 elderly men and women yielded no change in abdominal fat.⁴⁷ BMI decreased by only 0.2 units on average in 54 middle-aged adults after practicing yoga for 60 minutes 3 times per week for 8 weeks.⁴⁸

In teenagers, 8 weeks of yoga, compared to no exercise at all, led to a decrease in body fat percentage (4.3%) but no change in body weight or BMI.⁴⁹ A 5-month multicomponent behavioral intervention with yoga was associated with significant decreases in BMI z scores (−0.15 in z score in intervention participants compared with −0.08 in usual care participants; P = .01) among obese adolescent girls.⁵⁰ After 12 weeks of yoga among 20 teenagers, weight decreased by 2 kg,⁵¹ and after 16 weeks there were similar decreases in weight among 53 obese adolescent girls.⁵²

Thus, there have been few studies on the relation between yoga and weight loss, and no randomized controlled trial has yet isolated the effect of yoga on weight loss beyond that obtained from diet and exercise. Studies to date on yoga and weight loss are challenged by small sample sizes, short follow-up, and lack of control groups. In addition, there appears little consistency in terms of duration of formal group sessions, duration of informal practices at home, and frequency of both. Nevertheless, studies suggest that yoga may be associated with weight loss or maintenance. It has been noted as well that people with an interest or belief in the benefit of yoga are more likely to participate in studies than those who are indifferent; for this reason, and since participants cannot be blinded to treatment, study results are likely to be biased toward yoga.⁵³ This bias can be mitigated by recruiting participants who are neutral in their attitude toward all treatment arms or to stratify for such attitudes during randomization.⁵³

Neuropsychology and Behavior

Multiple mechanisms may explain associations observed between yoga and weight loss and maintenance. Although nonstrenuous yoga practice may not substantially influence energy balance,⁵⁴ a vigorous session may result in a 250 kcal expenditure.^8,55 Moreover, muscle and joint stretching during yoga may alleviate back pain, which in turn may allow for increased exercise. Yet the ability for yoga to facilitate weight loss or maintenance may chiefly be through its effects on neuropsychology and behavior (Figure 1).

Figure 1.

Benefits of Yoga in the Management of Overweight and Obesity.

Attention to the breath and body position during yoga practice is a form of mindfulness training. This mindfulness is characterized by a heightening of the following activities: (a) observing (attending to, or noticing, internal and external stimuli, such as sensations, emotions, cognitions, sights, sounds, and smells); (b) describing (noting or mentally labeling these stimuli with words); (c) acting with awareness (attending to one’s current actions, as opposed to behaving automatically or absent-mindedly); (d) nonjudging of inner experience (greater objectivity, or refraining from evaluation of one’s sensations, cognitions, and emotions); and (e) nonreactivity to inner experience (allowing thoughts and feelings to come and go, without attention getting caught up in them).^56,57 In the brain, mindfulness may be related to changes in activation of regions involved with attention (prefrontal cortex), conflict resolution (dorsal anterior cingulated cortex), and emotional processing (medial/orbitofrontal cortices).⁵⁸ Moderate-to-severe stress appears to increase growth of the amygdala and shrink the prefrontal cortex and hippocampus, whereas stress reduction leads to decrease in amygdala volume.⁵⁹ Although yoga is actually considered a type of meditation,⁶⁰ yoga is associated with improvements in more areas of mindfulness than is sitting meditation.⁵⁷

Increased mindfulness may be a key component to weight loss.⁶¹ Heightened mindfulness of the body and its behaviors may spill over from the yoga practice to everyday life. This mindfulness in turn may help individuals address emotional eating (eating in response to negative emotions such as boredom, stress, or sadness) and external eating (eating in response to food-related stimuli such as the taste, sight, or smell of palatable foods), both of which have been associated with weight gain, and control of which have been associated with weight loss.⁶¹ In addition, mindfulness may lead to greater positive outcomes expectancies (self-control, self-confidence), which correlate with weight loss in a bidirectional manner.⁴²

Mindfulness-training through yoga may also generate the relaxation response outside the yoga session, which can offset the physiological effects caused by perceived stress,⁶² acutely and long-term.⁶³ The sense of relaxation that comes with the relaxation response occurs as a result of decreased oxygen consumption and carbon dioxide elimination; reduced blood pressure, heart rate, and respiratory rate; and low-frequency heart rate oscillations.⁶⁴ Alterations in neural oscillations (brain waves) may also occur.⁶⁵ Changes in sympathetic and parasympathetic neural activity result as certain yoga practices slow respiration to a rate that coincides with the frequency of Mayer waves (rhythmic fluctuations in blood pressure and heart rate under the control of the autonomic nervous system).⁶³ By overlapping respiratory rate and cardiovascular rhythms, sympathetic and vagal outflows synchronize, cerebral blood flow changes, and a sense of well-being develops.⁶³ The net effect is such that the relaxation response helps individuals cope with stressful situations that may lead to addictive behaviors,⁶⁵ such as comfort food overconsumption.⁶⁶

Inflammation and Metabolism

Obesity is characterized by systemic inflammation: levels of pro-inflammatory mononuclear cells, interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), C-reactive protein (CRP), and matrix metalloproteinase-9 are all higher in obese individuals compared to normal-weight controls.⁶⁷ Fat cells secrete many of these pro-inflammatory cytokines, which in turn are linked with obesity-related chronic conditions, such as cardiovascular disease⁶⁷ and fatty liver.⁶⁸ Physical fitness, beyond helping to minimize body fatness, is associated with lower systemic inflammation.^69-71 In contrast, psychological stress^72,73 and depression⁷⁴ are associated with higher levels of inflammation. When compared to yoga novices (those who practice yoga ≤12 times in their lives), experts (those who have practiced yoga 1 to 2 times per week for at least 2 years and at least twice per week for past year) have been found to have lower levels of inflammatory IL-6.⁷⁵ The cause remains uncertain; however, rather than resulting from the physical postures or breathing exercises, immune modulation likely derives from psychosocial stress reduction from the meditative or relaxing component of yoga since similar changes have been observed in studies of meditation.^76-78

The adipocytokines leptin and adiponectin, both secreted by fat cells, may augment or dampen inflammation: leptin stimulates monocyte and T-cell release of IL-6 and TNF-α, activates macrophages, and promotes CRP production; adiponectin enhances production of anti-inflammatory IL-10 and decreases CRP, IL-6, and TNF-α.³⁰ Leptin also acts to decrease appetite and increase energy expenditures, and exogenous leptin administration has been shown to stimulate sympathetic nervous system activity, which in turn has been associated with the development of insulin resistance and an increase in cardiovascular disease risk.⁷⁹ Greater frequency and years of yoga practice have been associated with lower leptin levels and a higher adiponectin-to-leptin ratio, independent of BMI, cardiorespiratory fitness, central adiposity, and mood.³⁰ In addition, several,^80-84 but not all,^85,86 recent studies also suggest that regular yoga practice decreases circulating cortisol, exposure to which has been associated with higher leptin⁸⁷ and visceral adiposity.⁸⁸

In obese individuals, leptin resistance may develop and its sympatho-excitatory role may be depressed, leading to weight gain and lower than expected blood pressures.⁸⁹ Low sympathetic nervous system activity may be a risk factor for weight gain, but sympathetic activity increases in response to weight gain, thereby attenuating the original impairment.⁹⁰ As increased sympathetic activity may be associated with increased energy expenditure,⁹⁰ yoga’s ability to attenuate such activity may be counterproductive to weight loss.⁹¹

Discussion

Current recommendations for the lifestyle management of obesity include a low-calorie diet (eg, a deficit of 500-1000 kcal/day), physical activity (at least 30 minutes or more of moderate-intensity exercise most days of the week), and behavior therapy (strategies that provide tools for overcoming barriers to compliance with dietary and physical activity recommendations).⁹² Yoga may be considered a form of behavioral therapy. However, yoga does not incorporate all the components of behavioral therapy (self-monitoring, stimulus control, problem solving, contingency management, cognitive restructuring, and social support) and is thus not a replacement.⁹² However, yoga may act as a stepping stone to more intense behavioral therapy. Moreover, compared to other mindfulness practices, such as the body scan or sitting meditation, yoga may more easily allow for the transfer of mindfulness into everyday life since it requires attention to the body while it is moving.⁵⁷

The regular practice of yoga may assist the lifestyle management of overweight and obesity by (a) increasing energy expenditure during practice sessions; (b) facilitating exercise outside of the sessions by reducing back and joint pain; (c) heightening mindfulness, improving mood, and reducing stress, which may reduce food intake; and (d) allowing practitioners to feel more connected to their bodies, leading to enhanced awareness of satiety and the discomfort of overeating.⁸ In addition, obese individuals have reported lower levels of pleasure during exercise than nonobese individuals,⁹³ and exercise intensity is perceived to be higher in obese than normal-weight individuals.⁹⁴ Yoga may be a stepping stone, or precursor, to more vigorous physical activities.⁸ Moreover, the commitment and discipline of regular yoga practice, as well as the sense of community and support of group classes, may prepare an individual for diet and physical activity changes.⁸

Conclusions

Yoga may be most beneficial in the treatment of overweight and obesity before an individual begins a diet and exercise program. Although no guidelines currently exist for such a prescription, based on our experience, we propose the following: 3 months of formal, instructor-led yoga classes of 45 to 60 minutes once or twice per week. This schedule allows for the individual to become comfortable with yoga and begin to develop mindfulness and relaxation and physical benefits. The practitioner can do the yoga standing or sitting, depending on comfort and comorbid conditions (Figure 2 and Supplementary Figures [the online supplement figures are available at http://ajl.sagepub.com/supplemental]). She should practice on her own for 20 minutes each day on which there are no group classes. During these informal sessions, the individual can do an abbreviated program, beginning with a short period of meditation or relaxation (5 minutes) followed by a series of postures (15 minutes), and ending with a period of rest (5 minutes). As the practitioner becomes more comfortable and proficient with yoga, she may include additional postures and more frequent or longer periods of practice. She may start a diet and exercise weight loss program after 3 months, unless motivated to do so earlier. Ideally, the individual will continue with as much of the formal and informal yoga sessions as possible once the diet and exercise changes begin.

Figure 2A.

Yoga Poses in the Management of Overweight and Obesity.

Figure 2B.

Yoga Poses in the Management of Overweight and Obesity.

There are few risks, side effects, or adverse events associated with yoga practice. Muscle strain may be the most likely. However, one should confer with a physician before starting the recommended yoga program. Any pain during yoga practice is reason to stop and discuss the pain with a yoga instructor or physician. As with any physical activity, caution is recommended for individuals with cardiac or pulmonary disease and consultation with a physician is recommended. Although individuals with chronic obstructive pulmonary disease and hypertension appear disinclined to do yoga,⁵ whether this reflects a fear that yoga may compromise breathing or elevate blood pressure is uncertain, but no evidence to date suggests this happens with any regularity.

Footnotes

Acknowledgements

We would like to thank Ken Kula, Ross Papalardo, Amanda Mendelsohn, and Precious Lopez for help with preparation of the figures. The research was supported by institutional funds of the Cleveland Clinic Wellness Institute.

References

Sharpe

Blanck

Williams

Ainsworth

Conway

. Use of complementary and alternative medicine for weight control in the United States. J Altern Complement Med. 2007;13:217-222.

Barnes

Bloom

Nahin

. Complementary and alternative medicine use among adults and children: United States, 2007. Natl Health Stat Report. 2008;(12):1-23.

McCall

. 50 Health conditions benefited by yoga (with references). http://www.drmccall.com/yoga/54condwithrefs.pdf. Updated 2011. Accessed July 27, 2012.

Bertisch

Wee

McCarthy

. Use of complementary and alternative therapies by overweight and obese adults. Obesity (Silver Spring). 2008;16:1610-1615.

Birdee

Legedza

Saper

Bertisch

Eisenberg

Phillips

. Characteristics of yoga users: results of a national survey. J Gen Intern Med. 2008;23:1653-1658.

National Center for Complementary and Alternative Medicine. Get the facts: Yoga for health. http://nccam.nih.gov/health/yoga/introduction.htm. Accessed November 28, 2012.

Ross

Thomas

. The health benefits of yoga and exercise: a review of comparison studies. J Altern Complement Med. 2010;16:3-12.

Kristal

Littman

Benitez

White

. Yoga practice is associated with attenuated weight gain in healthy, middle-aged men and women. Altern Ther Health Med. 2005;11(4):28-33.

Sherman

Cherkin

Wellman

. A randomized trial comparing yoga, stretching, and a self-care book for chronic low back pain. Arch Intern Med. 2011;171:2019-2026.

10.

Tilbrook

Cox

Hewitt

. Yoga for chronic low back pain: a randomized trial. Ann Intern Med. 2011;155:569-578.

11.

Khalsa

. Yoga as a therapeutic intervention: a bibliometric analysis of published research studies. Indian J Physiol Pharmacol. 2004;48:269-285.

12.

Bussing

Ostermann

Ludtke

Michalsen

. Effects of yoga interventions on pain and pain-associated disability: a meta-analysis. J Pain. 2012;13:1-9.

13.

Williams

Abildso

Steinberg

. Evaluation of the effectiveness and efficacy of Iyengar yoga therapy on chronic low back pain. Spine (Phila Pa 1976). 2009;34:2066-2076.

14.

Wren

Wright

Carson

Keefe

. Yoga for persistent pain: new findings and directions for an ancient practice. Pain. 2011;152:477-480.

15.

Sherman

Cherkin

Erro

Miglioretti

Deyo

. Comparing yoga, exercise, and a self-care book for chronic low back pain: a randomized, controlled trial. Ann Intern Med. 2005;143:849-856.

16.

Brosseau

Wells

MacLeay

. Efficacy of aerobic exercises for osteoarthritis (part II): a meta-analysis. Phys Ther Rev. 2004;9(3):20.

17.

Pilkington

Kirkwood

Rampes

Richardson

. Yoga for depression: the research evidence. J Affect Disord. 2005;89(1-3):13-24.

18.

Tsang

Chan

Cheung

. Effects of mindful and non-mindful exercises on people with depression: a systematic review. Br J Clin Psychol. 2008;47(pt 3):303-322.

19.

Uebelacker

Epstein-Lubow

Gaudiano

Tremont

Battle

Miller

. Hatha yoga for depression: critical review of the evidence for efficacy, plausible mechanisms of action, and directions for future research. J Psychiatr Pract. 2010;16:22-33.

20.

Uebelacker

Tremont

Epstein-Lubow

. Open trial of Vinyasa yoga for persistently depressed individuals: evidence of feasibility and acceptability. Behav Modif. 2010;34:247-264.

21.

Streeter

Whitfield

Owen

. Effects of yoga versus walking on mood, anxiety, and brain GABA levels: a randomized controlled MRS study. J Altern Complement Med. 2010;16:1145-1152.

22.

Woolery

Myers

Sternlieb

Zeltzer

. A yoga intervention for young adults with elevated symptoms of depression. Altern Ther Health Med. 2004;10(2):60-63.

23.

Chong

Tsunaka

Tsang

Chan

Cheung

. Effects of yoga on stress management in healthy adults: a systematic review. Altern Ther Health Med. 2011;17(1):32-38.

24.

Innes

Bourguignon

Taylor

. Risk indices associated with the insulin resistance syndrome, cardiovascular disease, and possible protection with yoga: a systematic review. J Am Board Fam Pract. 2005;18:491-519.

25.

Mahajan

Reddy

Sachdeva

. Lipid profile of coronary risk subjects following yogic lifestyle intervention. Indian Heart J. 1999;51:37-40.

26.

Damodaran

Malathi

Patil

Shah

Suryavansihi

Marathe S

. Therapeutic potential of yoga practices in modifying cardiovascular risk profile in middle aged men and women. J Assoc Physicians India. 2002;50:633-640.

27.

Murugesan

Govindarajulu

Bera

. Effect of selected yogic practices on the management of hypertension. Indian J Physiol Pharmacol. 2000;44:207-210.

28.

Vogel

Bolling

Costello

. Integrating complementary medicine into cardiovascular medicine. A report of the American College of Cardiology Foundation Task Force on Clinical Expert Consensus Documents (Writing Committee to Develop an Expert Consensus Document on Complementary and Integrative Medicine). J Am Coll Cardiol. 2005;46:184-221.

29.

Tekur

Singphow

Nagendra

Raghuram

. Effect of short-term intensive yoga program on pain, functional disability and spinal flexibility in chronic low back pain: a randomized control study. J Altern Complement Med. 2008;14:637-644.

30.

Kiecolt-Glaser

Christian

Andridge

. Adiponectin, leptin, and yoga practice. Physiol Behav. 2012;107:809-813.

31.

Manchanda

Narang

Reddy

. Retardation of coronary atherosclerosis with yoga lifestyle intervention. J Assoc Physicians India. 2000;48:687-694.

32.

Posadzki

Ernst

. Yoga for asthma? A systematic review of randomized clinical trials. J Asthma. 2011;48:632-639.

33.

Aljasir

Bryson

Al-Shehri

. Yoga practice for the management of type ii diabetes mellitus in adults: a systematic review. Evid Based Complement Alternat Med. 2010;7:399-408.

34.

Birdee

Yeh

Wayne

Phillips

Davis

Gardiner

. Clinical applications of yoga for the pediatric population: a systematic review. Acad Pediatr. 2009;9:212-220.

35.

Galantino

Galbavy

Quinn

. Therapeutic effects of yoga for children: a systematic review of the literature. Pediatr Phys Ther. 2008;20:66-80.

36.

Moliver

Mika

Chartrand

Burrus

Haussmann

Khalsa

. Increased Hatha yoga experience predicts lower body mass index and reduced medication use in women over 45 years. Int J Yoga. 2011;4(2):77-86.

37.

Lee

Kim

. Effects of yoga exercise on serum adiponectin and metabolic syndrome factors in obese postmenopausal women. Menopause. 2012;19:296-301.

38.

Singh

Kyizom

Singh

Tandon

Madhu

. Influence of pranayamas and yoga-asanas on serum insulin, blood glucose and lipid profile in type 2 diabetes. Indian J Clin Biochem. 2008;23:365-368.

39.

Ornish

Brown

Scherwitz

. Can lifestyle changes reverse coronary heart disease? The Lifestyle Heart Trial. Lancet. 1990;336:129-133.

40.

Ornish

Scherwitz

Billings

. Intensive lifestyle changes for reversal of coronary heart disease. JAMA. 1998;280:2001-2007.

41.

Yogendra

Ambardekar

. Beneficial effects of yoga lifestyle on reversibility of ischaemic heart disease: caring heart project of International Board of Yoga. J Assoc Physicians India. 2004;52:283-289.

42.

Toobert

Glasgow

Radcliffe

. Physiologic and related behavioral outcomes from the Women’s Lifestyle Heart Trial. Ann Behav Med. 2000;22:1-9.

43.

Telles

Naveen

Balkrishna

Kumar

. Short term health impact of a yoga and diet change program on obesity. Med Sci Monit. 2010;16:CR35-CR40.

44.

Gokal

Shillito

Maharaj

. Positive impact of yoga and pranayam on obesity, hypertension, blood sugar, and cholesterol: a pilot assessment. J Altern Complement Med. 2007;13:1056-1057.

45.

Khatri

Mathur

Gahlot

Jain

Agrawal

. Effects of yoga and meditation on clinical and biochemical parameters of metabolic syndrome. Diabetes Res Clin Pract. 2007;78(3):e9-e10.

46.

Littman

Bertram

Ceballos

. Randomized controlled pilot trial of yoga in overweight and obese breast cancer survivors: effects on quality of life and anthropometric measures. Support Care Cancer. 2012;20:267-277.

47.

DiPietro

Seeman

Stachenfeld

Katz

Nadel

. Moderate-intensity aerobic training improves glucose tolerance in aging independent of abdominal adiposity. J Am Geriatr Soc. 1998;46:875-879.

48.

McCaffrey

Ruknui

Hatthakit

Kasetsomboon

. The effects of yoga on hypertensive persons in Thailand. Holist Nurs Pract. 2005;19:173-180.

49.

Seo

Lee

Figueroa

. Yoga training improves metabolic parameters in obese boys. Korean J Physiol Pharmacol. 2012;16:175-180.

50.

DeBar

Stevens

Perrin

. A primary care-based, multicomponent lifestyle intervention for overweight adolescent females. Pediatrics. 2012;129:e611-e620.

51.

Benavides

Caballero

. Ashtanga yoga for children and adolescents for weight management and psychological well being: an uncontrolled open pilot study. Complement Ther Clin Pract. 2009;15:110-114.

52.

Sabet-Sarvestani

Kargar

Kave

Tabatabaee

. The effect of dietary behavior modification on anthropometric indices in obese adolescent female students. Iranian J Pediatr. 2008;18(suppl 1):71-76.

53.

Andrade

. Transcendental meditation and components of the metabolic syndrome: methodological issues. Arch Intern Med. 2006;166:2553.

54.

Hagins

Moore

Rundle

. Does practicing hatha yoga satisfy recommendations for intensity of physical activity which improves and maintains health and cardiovascular fitness? BMC Complement Altern Med. 2007;7:40.

55.

Mody

. Acute effects of Surya Namaskar on the cardiovascular & metabolic system. J Bodyw Mov Ther. 2011;15:343-347.

56.

Shelov

Suchday

Friedberg

. A pilot study measuring the impact of yoga on the trait of mindfulness. Behav Cogn Psychother. 2009;37:595-598.

57.

Carmody

Baer

. Relationships between mindfulness practice and levels of mindfulness, medical and psychological symptoms and well-being in a mindfulness-based stress reduction program. J Behav Med. 2008;31:23-33.

58.

Froeliger

Garland

Modlin

McClernon

. Neurocognitive correlates of the effects of yoga meditation practice on emotion and cognition: a pilot study. Front Integr Neurosci. 2012;6:48.

59.

Davidson

McEwen

. Social influences on neuroplasticity: stress and interventions to promote well-being. Nat Neurosci. 2012;15:689-695.

60.

Kabat-Zinn

. Full Catastrophe Living: Using the Wisdom of Your Body and Mind to Face Stress, Pain, and Illness. 15th ed. New York, NY: Bantam Dell; 2009.

61.

Tapper

Shaw

Ilsley

Hill

Bond

Moore

. Exploratory randomised controlled trial of a mindfulness-based weight loss intervention for women. Appetite. 2009;52:396-404.

62.

Benson

Beary

Carol

. The relaxation response. Psychiatry. 1974;37:37-46.

63.

Bernardi

Sleight

Bandinelli

. Effect of rosary prayer and yoga mantras on autonomic cardiovascular rhythms: comparative study. BMJ. 2001;323:1446-1449.

64.

Dusek

Otu

Wohlhueter

. Genomic counter-stress changes induced by the relaxation response. PLoS One. 2008;3:e2576.

65.

Aron

. The transcendental meditation program’s effect on addictive behavior. Addict Behav. 1980;5:3-12.

66.

Dallman

Pecoraro

Akana

. Chronic stress and obesity: a new view of “comfort food.” Proc Natl Acad Sci U S A. 2003;100:11696-11701.

67.

Ghanim

Aljada

Hofmeyer

Syed

Mohanty

Dandona

. Circulating mononuclear cells in the obese are in a proinflammatory state. Circulation. 2004;110:1564-1571.

68.

Targher

Day

Bonora

. Risk of cardiovascular disease in patients with nonalcoholic fatty liver disease. N Engl J Med. 2010;363:1341-1350.

69.

Hamer

. The relative influences of fitness and fatness on inflammatory factors. Prev Med. 2007;44:3-11.

70.

Aronson

Sheikh-Ahmad

Avizohar

. C-Reactive protein is inversely related to physical fitness in middle-aged subjects. Atherosclerosis. 2004;176:173-179.

71.

Kasapis

Thompson

. The effects of physical activity on serum C-reactive protein and inflammatory markers: a systematic review. J Am Coll Cardiol. 2005;45:1563-1569.

72.

Steptoe

Hamer

Chida

. The effects of acute psychological stress on circulating inflammatory factors in humans: a review and meta-analysis. Brain Behav Immun. 2007;21:901-912.

73.

Kiecolt-Glaser

Preacher

MacCallum

Atkinson

Malarkey

Glaser

. Chronic stress and age-related increases in the proinflammatory cytokine IL-6. Proc Natl Acad Sci U S A. 2003;100:9090-9095.

74.

Howren

Lamkin

Suls

. Associations of depression with C-reactive protein, IL-1, and IL-6: a meta-analysis. Psychosom Med. 2009;71:171-186.

75.

Kiecolt-Glaser

Christian

Preston

. Stress, inflammation, and yoga practice. Psychosom Med. 2010;72:113-121.

76.

Davidson

Kabat-Zinn

Schumacher

. Alterations in brain and immune function produced by mindfulness meditation. Psychosom Med. 2003;65:564-570.

77.

Carlson

Speca

Faris

Patel

. One year pre-post intervention follow-up of psychological, immune, endocrine and blood pressure outcomes of mindfulness-based stress reduction (MBSR) in breast and prostate cancer outpatients. Brain Behav Immun. 2007;21:1038-1049.

78.

Pace

Negi

Adame

. Effect of compassion meditation on neuroendocrine, innate immune and behavioral responses to psychosocial stress. Psychoneuroendocrinology. 2009;34:87-98.

79.

Flanagan

Vaile

Petley

. Gender differences in the relationship between leptin, insulin resistance and the autonomic nervous system. Regul Pept. 2007;140:37-42.

80.

Curtis

Osadchuk

Katz

. An eight-week yoga intervention is associated with improvements in pain, psychological functioning and mindfulness, and changes in cortisol levels in women with fibromyalgia. J Pain Res. 2011;4:189-201.

81.

Yadav

Magan

Mehta

Sharma

Mahapatra

. Efficacy of a short-term yoga-based lifestyle intervention in reducing stress and inflammation: preliminary results. J Altern Complement Med. 2012;18:662-667.

82.

Rocha

Ribeiro

Rocha

. Improvement in physiological and psychological parameters after 6 months of yoga practice. Conscious Cogn. 2012;21:843-850.

83.

Martarelli

Cocchioni

Scuri

Pompei

. Diaphragmatic breathing reduces exercise-induced oxidative stress. Evid Based Complement Alternat Med. 2011;2011:932430.

84.

Vadiraja

Raghavendra

Nagarathna

. Effects of a yoga program on cortisol rhythm and mood states in early breast cancer patients undergoing adjuvant radiotherapy: a randomized controlled trial. Integr Cancer Ther. 2009;8:37-46.

85.

Yoshihara

Hiramoto

Sudo

Kubo

. Profile of mood states and stress-related biochemical indices in long-term yoga practitioners. Biopsychosoc Med. 2011;5(1):6.

86.

Bowden

Gaudry

Gruzelier

. A comparative randomised controlled trial of the effects of brain wave vibration training, iyengar yoga, and mindfulness on mood, well-being, and salivary cortisol. Evid Based Complement Alternat Med. 2012;2012:234713.

87.

Wabitsch

Jensen

Blum

. Insulin and cortisol promote leptin production in cultured human fat cells. Diabetes. 1996;45:1435-1438.

88.

Bergasa

Mehlman

Bir

. Aerobic exercise: a potential therapeutic intervention for patients with liver disease. Med Hypotheses. 2004;62:935-941.

89.

Quilliot

Bohme

Zannad

Ziegler

. Sympathetic-leptin relationship in obesity: effect of weight loss. Metabolism. 2008;57:555-562.

90.

Snitker

Macdonald

Ravussin

Astrup

. The sympathetic nervous system and obesity: role in aetiology and treatment. Obes Rev. 2000;1:5-15.

91.

Streeter

Gerbarg

Saper

Ciraulo

Brown

. Effects of yoga on the autonomic nervous system, gamma-aminobutyric-acid, and allostasis in epilepsy, depression, and post-traumatic stress disorder. Med Hypotheses. 2012;78:571-579.

92.

National Institutes of Health. Clinical Guidelines on the Identification, Evaluation, and Treatment of Overweight and Obesity in Adults (NIH Publication No. 98-4083). Bethesda, MD: National Heart, Lung, and Blood Institute; 1998.

93.

Ekkekakis

Lind

Vazou

. Affective responses to increasing levels of exercise intensity in normal-weight, overweight, and obese middle-aged women. Obesity (Silver Spring). 2010;18:79-85.

94.

Ekkekakis

Lind

. Exercise does not feel the same when you are overweight: the impact of self-selected and imposed intensity on affect and exertion. Int J Obes (Lond). 2006;30:652-660.