In 2014, Dr. Ann Caldwell was pursuing post-doctoral fellowship work at Emory University in Atlanta when she met a graduate student with whom she shared a common interest: yoga. Caldwell had been doing yoga for about a decade, primarily to maintain her physical conditioning, but after the meeting, her interest took a new turn that ultimately provided the impetus for a new weight-loss trial now underway at the Anschutz Health and Wellness Center.

The grad student Caldwell met, Paul Dallaghan, had far more than a casual commitment to yoga. He is an internationally recognized master in the techniques of pranayama (breathing) and asana (body posture) with a longtime dedication to teaching it to others. In addition to focusing his PhD dissertation on yoga, Dallaghan owns a teacher training retreat in Thailand that Caldwell was interested in attending.

In preparation for her month-long stay there, Caldwell said she was required to begin learning basic breathwork techniques. Drawing in breath through her nose and slowly exhaling, it turned out, opened her eyes.

“I noticed a lot of differences in myself in terms of sleep quality, appetite and mood,” Caldwell said. “I learned that yoga is so much more than the exercise component that it is commercially seen as in the U.S.”

The month-long teacher training at Dallaghan’s retreat in the techniques of breathwork, posture and meditation intensified Caldwell’s belief in the broad benefits of yoga.

“It was life-changing,” said Caldwell, now a health psychologist and assistant professor in the Division of Endocrinology, Metabolism and Diabetes at the University of Colorado School of Medicine.

Yoga for weight loss?

The experience also helped to form the basis for the trial she currently leads and designed with divisional colleagues post-doctoral fellow Dr. Sarah Purcell and internal medicine specialist Dr. Victoria Catenacci, who also practices at the UCHealth Diabetes and Endocrinology Clinic – Anschutz Medical Campus.

The study is now underway with 16 participants recruited from the CU Anschutz Medical Campus and the wider community. It tests the feasibility of incorporating yoga practices with a traditional behavioral weight loss program as an approach to controlling blood glucose, managing diet and appetite, and improving activity and mental health.

The trial’s innovative approach is sorely needed, Caldwell and Purcell note in their description of the study. They point out that while behavioral weight loss programs typically help people lose 5% to 10% of their body weight over six months, they often regain most or all of it within a year. In addition, the prevalence of obesity, which can lead to a host of additional health problems, has increased dramatically over the past two decades.

That challenge led Caldwell to draw on her experience in Thailand and work with Purcell and Catenacci to incorporate Eastern yoga elements into the new study.

“I felt there was a unique opportunity to bring aspects of an ancient traditional practice to people who are trying to lose weight,” Caldwell said.

East meets West: Have traditional forms of yoga been ‘lost in translation?’

It’s an approach that is ripe for exploration. A small number of studies have suggested that yoga may help people who are overweight or struggling with obesity to reduce the amount of energy from the food they eat (aka “energy intake”) and increase their physical activity, as Caldwell and Purcell wrote in a July 2021 article they co-authored in Obesity Science and Practice.

However, the East is the source of yoga practices that stretch back thousands of years, with potential physiological and mental health benefits that extend far beyond weight loss. These practices, especially pranayama and meditation, “generally are not reflected as yoga is practiced in the West,” Caldwell said. For example, studies in the United States that she and Purcell reviewed frequently used other exercises, such as Pilates, in addition to yoga postures.

That has resulted in the fundamental factors of “traditional yoga practice” being “lost in translation,” as the two researchers put in the study description. The new study aims to bridge this scientific and cultural gap.

“We are trying to marry traditional Eastern yoga practices and Western approaches to rigorous clinical research,” Caldwell said.

Plenty of help for study participants

The behavioral weight loss component of the trial includes weekly classes led by Kristen Bing, a registered dietitian with the Anschutz Health and Wellness Center. Those sessions center on strategies for portion control, calorie tracking and restriction, goal-setting, increased exercise and other established techniques. Participants take oral glucose tolerance tests at the start of and after the study and track their activity levels with Fitbits. They also receive memberships to the Anschutz Health and Wellness Center to make it convenient for them to meet goals for moderate-intensity physical exercise.

The yoga component – no prior experience required – consists of a set of 12 pre-recorded instruction videos designed and led by Dallaghan for people with high body mass indexes (27 to 45) and various physical issues that can make exercise difficult and discouraging.

“Many times people who have larger bodies have issues like lower back pain and physical function limitations,” Purcell said. “Yoga can be a way to get some exercise even if it is very low burden, and that can help them start to lose weight.” With that success, they may be able to engage in gradually more intense activity, she added.

More than calories burning

Yoga, practiced in its ancient form, offers other potential benefits for people trying to lose weight, Caldwell said, including increasing a sense of well-being, reducing stress and improving sleep. All of these could “augment other efforts, like establishing healthy eating patterns,” she said.

The idea is that for some people, losing weight requires more than simply cutting calories, eating healthier food, exercising more or simply increasing their willpower. They may also need strategies to reduce their stress, Caldwell said.

She explained that behavioral weight loss programs rely on people establishing dietary and physical activity goals and strategies to achieve them. In so doing, people are asked to “trade their food and go against their impulses.”

For those dealing with emotional issues, that can be a difficult trade-off, Caldwell said. That’s because stress and problems with emotion regulation may interfere with areas of the brain people need “to act in more goal-oriented ways,” and short-circuit efforts to make healthy choices, she said. Traditional yoga, with its emphasis on breathwork, mindfulness, and meditation, could restore emotional balance and potentially even trigger shifts in the nervous system and the vagus nerve – the key regulator of digestion, among many other functions, Caldwell said.

Testing yoga as a new source of weight-loss support

She emphasized that there is still much work to be done to test that hypothesis. But at the very least, yoga practice could offer a new support strategy for people trying to lose weight.

“The question is how can we make the lifestyle changes that we know work for weight management easier to do in the short- and the long-term?” Caldwell said.

“Everyone is different,” Purcell added. “In the obesity field in general, we can all agree that one intervention is not going to lead to the same outcome with every single person.” An approach that incorporates yoga, Purcell added, “is not the be-all and end-all or some magic intervention that is going to lead to huge decreases in body weight. But we do think that are certain things about yoga that make it unique.”

Caldwell and Purcell aim to extend their research by applying for funding for a larger trial with the National Institutes of Health, but they must first determine if their current study design is feasible. They will be looking at how well participants adhered to the regimen and were satisfied with it, while also noting any adverse events, incorporating participant feedback and making necessary tweaks based on the information. They will also measure clinical data, like changes in body weight and composition, glucose levels, cholesterol and more.

Ultimately, Caldwell said, the trial is one step in an effort to find ways to not only help people lose weight but also keep it off. There is no one-size-fits-all approach.

“While we can get people to lose weight, there is a lot of individual variability,” she said. “A lot of people are trying but it’s not working to keep weight off in the long term.” With the aid of Dallaghan’s “substantial expertise,” Caldwell believes the new study offers a “unique approach to yoga research in the United States.”