About one in five Americans who have lost weight have kept those pounds off long-term. A new Cal Poly study powered by machine learning reveals some secrets to how people lose weight and keep it off: persevering despite setbacks; regularly looking back at what their life was like before the weight loss; and remaining focused on their health.

The findings, published Feb. 9 in Obesity: The Journal of The Obesity Society, are from the first large-scale study that allowed weight loss maintainers to identify in their own words what helped them succeed. The more than 6,000 participants were WW members who had lost more than 50 pounds on average and kept it off for more than three years. They answered open-ended questions about their motivations (in the past and present) and strategies for maintaining weight loss and the resulting lifestyle changes. Researchers then used machine learning to group responses by topic.

“One of the most impressive findings was how weight-loss maintainers described perseverance in the face of setbacks,” said Suzanne Phelan, a professor in Cal Poly’s Kinesiology and Public Health Department, who led the study. “Weight-loss maintainers saw setbacks as part of their successful journey. Setbacks were not described as failures. They were seen as a temporary interruption in their path. Many weight-loss maintainers described getting back on track at the next meal or the next day and measuring overall success based on long-term goals.”

Results from the open-ended study revealed additional insights into the motivations behind losing weight and keeping it off. Respondents often mentioned such health issues as diabetes and heart conditions. Others cited concerns about mobility, appearance, suggestions from family or friends and the need for change because they often felt tired. Respondents offered advice to others going through their own health and weight-loss journey.

Many said that perseverance was essential in overcoming the inevitable setbacks. They encouraged others to take it day by day, use WW workshops to reset mentally after difficult weeks, and embrace long-term goals. Weight-loss maintainers also described consistently tracking food intake as an essential skill within a healthy lifestyle.

The study also demonstrated that weight-loss maintainers:

- remain motivated to maintain the weight loss mostly by health and appearance, as well as reflecting on past experiences;

- believe that the most important changes include reduced pain, medical status, confidence, feeling more at ease and comfortable mentally and physically, fitness and body image; and

- describe the consequences of successful weight loss as challenges related to the cost of buying new clothes, unexpected criticism from others, sagging skin, and the effort needed to keep up a healthy lifestyle.

The findings may lead to changing what topics are emphasized when people are counseled on how to maintain weight loss.

“As a lifestyle interventionist and researcher, I’m excited to think about how to promote perseverance, encourage tracking of intake, and make changes in medical status more salient during the weight-loss journey,” Phelan said.

Phelan and her co-authors recently published another study that examined food-choice motivations among 4,000 long-term weight-loss maintainers. Their findings, published Dec. 30 in the Journal of Human Nutrition and Dietetics, found that compared to weight-stable individuals with obesity, those who had maintained weight loss made food decisions based more on health and weight control and less on price.

Also, weight-loss maintainers were more likely to consider the future consequences of their current behaviors.

“At WW and throughout my clinical experience, I’ve seen firsthand that someone’s mindset and perspective are crucial to help them build healthy habits and drive sustainable weight loss and management,” said Gary Foster, co-author of the study and chief scientific officer at WW. “We hope that these findings encourage other people going through a similar journey and equip them with the tools that they need to optimize their own success.”

This research was supported by a grant from New York-based WW International Inc. and student fellowship support from the William and Linda Frost Fund at Cal Poly in San Luis Obispo.