Maintaining a healthy weight during the golden years is a priority for many older adults. While previous research has shown that cutting calories can lower disease risk factors, it's unclear whether it can have a long-term positive impact on disease and disability.
With a $2.1 million grant from the National Institutes of Health, researchers at Wake Forest University School of Medicine will evaluate the potential benefits of diet interventions such as time-restricted eating and caloric restriction.
"We will study whether these diet interventions provide benefit in preventing disease in addition to lowering risk factors," said Stephen Kritchevsky, Ph.D., professor of gerontology and geriatric medicine at Wake Forest University School of Medicine, co-director of the Sticht Center for Healthy Aging and Alzheimer's Prevention and principal investigator of the study.
The Health, Aging and Later-Life Outcomes Planning Grant (HALLO-P) is a three-year planning grant to develop the protocol for a larger five-year, multi-site trial to compare outcomes in older persons who either cut calories or only eat their food during certain hours of the day.
In this initial phase, researchers will recruit 120 adults over the age of 60 with a body mass index between 27 and 37. Participants will be randomized into one of three study groups. Two of the study groups will follow meal plans with reduced calories, with one group meeting in person, and the second group meeting virtually. The third group will have no restrictions on their daily calories, but meals will be limited to an eight-hour window. Participants in all groups will be asked to increase their physical activity by walking.
The study also involves several unique assessments. In addition to measuring blood pressure, cholesterol and glucose levels, we will also conduct bone density scans and blood tests to predict disease risk."
Stephen Kritchevsky, Ph.D., professor of gerontology and geriatric medicine, Wake Forest University School of Medicine
The study also uses a sophisticated method to determine weight loss targets called the doubly labeled water method, which helps assess energy expenditure.
"Participants drink a small amount of water that contains greater amounts of 'heavy' versions of hydrogen and oxygen than is found in tap water," Kritchevsky said. "In about a week, we measure the amount of this water in urine to calculate the number of calories that should be consumed for restriction. It's very precise."
According to Kritchevsky, researchers will assess how decreasing energy intake or changing the pattern of eating throughout the day can improve outcomes in older adults.
"Behavior change is hard, and people need assistance," Kritchevsky said. "The study will include frequent touchpoints and support for participants."