Weighted Vests Fail to Shield Bones During Weight Loss in Older Adults

A 12-month clinical trial involving 150 older adults has delivered sobering news for those hoping weighted vests might solve a persistent medical puzzle: how to help aging patients lose weight without sacrificing bone strength.

The study, published in JAMA Network Open, found that neither wearing weighted vests for seven hours daily nor participating in supervised resistance training prevented the bone loss that typically accompanies intentional weight reduction in people over 60. All participants lost similar amounts of hip bone density—between 1.2% and 1.9%—regardless of their intervention group.

The Bone Loss Dilemma

“While we hoped that replacing lost weight externally or increasing mechanical loading through exercise would preserve bone, our findings show that these strategies alone may not be enough,” said Kristen M. Beavers, the study’s lead author and professor at Wake Forest University School of Medicine.

The research addresses a clinical catch-22 that affects millions of Americans. Weight loss improves cardiovascular health and joint function in older adults with obesity, but it also weakens bones, potentially increasing fracture risk. With an estimated 72 million Americans expected to be 65 or older by 2030—and most of them overweight or obese—finding safe weight-loss protocols has become increasingly urgent.

Testing an Innovative Strategy

The INVEST in Bone Health trial tested whether weighted vests could trick the skeleton into maintaining its strength by replacing lost body weight with external load. Participants in the vest group wore their devices an average of 7.1 hours per day, with vest weight adjusted weekly to match approximately 78% of their weight loss.

The approach seemed logical. Previous smaller studies suggested weighted vests could preserve bone density during exercise, and the researchers’ own pilot study in 2017 showed promising signals for hip bone preservation.

All three study groups—weight loss alone, weight loss plus weighted vests, and weight loss plus resistance training—achieved impressive results in shedding pounds, losing between 9% and 11.2% of their body weight over 12 months. Adherence was high across interventions, with resistance training participants attending 71% of prescribed sessions.

Key Study Findings

• Hip bone mineral density decreased significantly in all groups, with no protective effect from weighted vests or resistance training
• Weighted vest users maintained their regimen for an average of 7.1 hours daily throughout the year-long study
• Both weighted vest and resistance training groups showed increased bone formation markers compared to weight loss alone
• Resistance training provided additional benefits including improved strength and physical activity levels
• More than half of weighted vest participants reported satisfaction with the intervention

Unexpected Complications

The study revealed some surprising findings that may have influenced the results. Participants experienced less bone and muscle loss than typically seen in weight-loss studies, possibly due to the nutritionally complete meal replacement program that provided adequate calcium, vitamin D, and protein throughout the intervention.

While all groups lost lean muscle mass, the magnitude was smaller than expected—less than 2% compared to the 20% muscle loss often seen with 10% weight reduction. Since muscle and bone health are closely linked, this muscle preservation may have reduced the potential for the interventions to show additional bone-sparing effects.

Clinical Implications

The findings don’t spell doom for weighted vests in fitness regimens. Studies continue to show these devices help older adults improve strength and physical performance—key factors in preventing disability. Beavers emphasized that bone health represents just one piece of the fracture prevention puzzle.

“Fractures in older adults can be life-altering,” she noted. “Our study reinforces that we need to think beyond traditional exercise and consider new or combined approaches to protect bone during weight loss.”

The research team is already exploring alternative strategies, including a collaboration studying how osteoporosis medications might help preserve bone during weight loss—a trial called BEACON (Bone, Exercise, Alendronate, and Caloric Restriction).

The Medication Factor

The timing of this research proves particularly relevant as new weight-loss medications like Wegovy and Mounjaro gain widespread adoption. These highly effective drugs can produce rapid weight loss, raising concerns about accelerated bone loss in older patients who are already at elevated fracture risk.

The study included participants with a mean age of 66.4 years, with nearly half presenting with low bone mass at baseline. While demographic factors varied across racial lines—approximately 29% were African American or Black, and 67% were White—the bone loss patterns remained consistent across groups.

For now, the search continues for effective strategies to protect skeletal health during weight loss in aging populations. The Wake Forest team’s work underscores the complexity of managing obesity in older adults, where the benefits of weight reduction must be carefully balanced against potential bone health consequences.