Older adults who wore weighted vests while restricting calories maintained their resting metabolic rate and regained less weight over two years than participants who dieted without added load.
By yourNEWS Media Newsroom.
Wearing a weighted vest for much of the day while following a calorie-restricted diet may help the body resist the metabolic slowdown that often contributes to weight regain, according to a small pilot study conducted by Wake Forest University researchers.
The six-month study involved 18 adults ages 60 and older who had obesity. All participants followed a calorie-restriction program, but half were also instructed to wear adjustable vests carrying approximately 10% of their body weight for as long as 10 hours each day.
Both groups lost similar amounts of weight during the active intervention. Their longer-term outcomes, however, differed substantially.
Participants who wore the vests maintained a stable resting metabolic rate during the weight-loss period and still had roughly half of their original weight loss two years later, according to the study.
Those assigned to calorie restriction alone experienced the metabolic decline commonly associated with dieting and had regained virtually all of the lost weight by the two-year follow-up.
The findings are preliminary because the study involved only 18 people, but researchers said the results support further investigation into whether maintaining mechanical load during weight loss can improve long-term outcomes.
“The underlying mechanism behind preventing weight regain with a weighted vest is plausible, the intervention is low-effort, and the two-year results are hard to ignore,” one participant was quoted as saying in an article by mindbodygreen that reported the findings.
Weight regain remains a frequent problem after calorie-restricted diets because the body adjusts to prolonged reductions in energy intake.
As body weight falls, resting metabolic rate often declines, meaning the body requires fewer calories to perform basic functions. That adjustment can create an energy imbalance in which a person must continue eating less than before simply to maintain the new weight.
The process is commonly called metabolic adaptation. Researchers have documented it in people who lose weight through dietary changes and other interventions.
The body may also respond to weight loss by increasing hunger, altering appetite hormones and becoming more efficient in its use of energy. Those changes can persist after dieting ends and make maintaining a lower weight increasingly difficult.
The Weight Regain Paradox, a book examining repeated cycles of dieting and regain, describes the body as responding to weight loss as though it were a threat to survival.
A review published in the Journal of the American College of Nutrition similarly examined high-protein diets and concluded that preserving metabolic rate during weight loss is important for maintaining results.
The Wake Forest pilot study tested whether replacing some of the physical load lost during dieting could reduce those compensatory changes.
Researchers divided the 18 participants into two groups. Nine followed calorie restriction alone, while the other nine wore adjustable weighted vests during normal daily activities in addition to following the same dietary program.
The vests were loaded to approximately 10% of each participant’s body weight. A person weighing 160 pounds, for example, would carry about 16 pounds under that protocol.
Participants were asked to wear the equipment for up to 10 hours daily rather than limiting use to exercise sessions.
At the end of six months, weight loss was comparable between the two groups. Measurements of resting energy expenditure, however, showed that the vest group maintained its metabolic rate while the diet-only group experienced the expected reduction.
Neither group was actively following the original intervention at the two-year assessment. Even so, participants who had worn the vests retained about half of their weight loss, while those who dieted without the added load had regained nearly all of it.
Researchers proposed that the outcome may involve a theoretical biological system known as the gravitostat.
Under the gravitostat theory, cells associated with the skeleton detect the mechanical force created by body weight and relay information about that load to the brain.
When a person loses body fat, the force placed on the skeleton decreases. Researchers have proposed that the brain may interpret that decline as a threat to the body’s preferred weight and activate responses intended to restore the missing mass.
Those responses could include reduced energy expenditure and greater appetite.
A weighted vest may partially replace the lost mechanical force, causing the body to sense that overall weight has not declined as much as it has on the scale. Researchers theorized that this artificial load could limit the metabolic and appetite responses that encourage regain.
The gravitostat remains a proposed mechanism rather than a settled scientific explanation. The Wake Forest study did not establish that skeletal load sensing directly caused the differences between the two groups.
The small number of participants also makes it difficult to determine whether the findings would apply to younger adults, people without obesity or individuals with different health conditions.
Larger studies will be needed to replicate the results, examine possible effects on appetite and body composition, and determine the safest amount and duration of weighted-vest use.
Extended use also requires practical and medical considerations.
Participants carried loads approaching 10% of their body weight, but people considering weighted equipment may need to begin with substantially less. Increasing the load gradually can allow time to assess comfort, balance and the effects on the knees, hips, back and feet.
“It feels heavy at first, but after a week you barely notice it,” one study participant said.
Proper fit and even distribution of weight across the torso are important, particularly when a vest is worn for several hours. Equipment that shifts while walking or places excessive pressure on the shoulders may increase discomfort or injury risk.
People with osteoporosis, balance problems, cardiovascular disease, arthritis, back pain or joint disorders should consult a medical professional before using a weighted vest. Older adults may also benefit from professional guidance because added load can increase fall risk.
Rucking, which involves walking while carrying weight in a backpack or vest, is another way to increase exercise intensity without running or performing high-impact movements. Its demands differ from wearing a vest throughout routine daily activities, however, and the two approaches should not be considered interchangeable.
The study does not show that weighted vests cause weight loss independently or eliminate the need for an appropriate diet, physical activity, sleep and continued behavioral support.
It also does not establish that a vest is safer or more effective than prescription weight-management medications for everyone. Pharmaceutical treatments have specific benefits and risks that should be considered individually with a health care provider.
The research instead suggests that preserving the physical load placed on the body during calorie restriction may influence metabolic adaptation and improve the likelihood of maintaining at least part of the resulting weight loss.
For researchers, the two-year difference between the groups offers a reason to investigate the intervention in larger and more diverse populations.
For individuals, the findings provide an early indication that a relatively simple tool may eventually become one component of a broader weight-maintenance strategy. Until additional evidence is available, weighted-vest use should be approached gradually and with attention to personal health, mobility and injury risk.
Source: Natural News
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