Photo caption: Robert “Trey” Coker. UAF photo by Leif Van Cise.
Coker, who has a Ph.D. in exercise physiology, worked at the time at the University of Arkansas for Medical Sciences’ Department of Geriatrics. He was familiar with the effects of inactivity on aging bodies but was experiencing it for the first time himself.
“That was an inflection point for me,” he said of the 2010 crash and his subsequent recovery. “I remember thinking that I had to do something.”
That effort went beyond just his own rehabilitation. A researcher at the University of Alaska Fairbanks Institute of Arctic Biology since 2013, Coker has spent the last 10 years addressing a vexing problem: How can people maintain their muscle mass in the face of physical inactivity or aging?
It’s a particular problem for elderly people who are overweight and might want to improve their health. Cutting calories is the most effective way for them to drop pounds, but, unless accompanied by exercise, they lose muscle along with fat.
“In the scenario I was in, activity wasn’t on the table,” Coker said. “That’s especially true for a lot of older individuals, and especially obese older individuals. It’s kind of a catch-22 for them.”
To develop the best nutritional strategy for this scenario, Coker used stable isotopes of common elements to track and monitor feeding-induced changes in muscle growth. That effort provided definitive evidence that a specific set of essential amino acids might just win the battle against muscle atrophy.
With the help of a group of Fairbanks-area seniors and an $11.8 million grant from the National Institutes of Health, Coker is exploring whether his proprietary meal replacement enriched with essential amino acids will eliminate the loss of skeletal muscle, even during weight loss in older obese individuals.
That, in turn, could offer a key to helping people stay active and functional in their later years.
“A lot of older individuals want to be active, but it’s hard for them without that muscle,” Coker said. “This whole thing is about maintaining independence as we age.”
Keeping muscle, losing fat
After downing more than 100 meal-replacement shakes in just four weeks, Ron Woolf reported with a hint of surprise that he was enjoying his vastly simplified diet.
“I think they taste good,” Woolf said with a smile. “I like it.”
Woolf, 64, began drinking five of them a day in July when he enrolled in Coker’s nutrition study. They’re the basis for a 1,200-calorie daily diet that research participants are asked to consume for 12 weeks.
Woolf, the chief financial officer at Golden Valley Electric Association, said his goal when he joined the study was to hit his “retirement weight” by the time he ends his career at the utility in December. In just a month he was down 17 pounds, but the study has also offered a fascinating picture of his fitness level and overall health, he said.
“This whole thing is about maintaining independence as we age.”
Melynda “Sheri” Coker, who is the clinical coordinator for the senior nutrition project and Coker’s wife, is gathering vast amounts of data from Woolf and other volunteers to help gauge whether the diet is having its intended effect.
It starts with a physical screening to see which volunteers are eligible to participate. Since then, Woolf has had scans to measure his body composition and bone density. Blood tests are monitoring his body functions, and on his wrist he wears an ActiGraph, a device that tracks his activity levels and sleep patterns.
A series of physical benchmarks through the study are recording his fitness level, including tests that measure grip strength, fitness levels during a six-minute walk, and how quickly he can get up from a lying-down position on the floor.
On top of that, Woolf’s grocery bill has shrunk considerably. The shakes are provided as part of the study, along with a vitamin supplement. He figured the simplest way to consume the other 400 calories he was allowed each day was to eat a healthy frozen meal.
“It’s fun to come in every week, and it’s not just about losing weight,” Woolf said of his regular testing sessions in the basement of UAF’s Murie Building. “I’ve done everything, and being able to get these other benefits is really an attractive part of this.”
The powder used to make the shakes is stored in dozens of containers locked up in Coker’s lab. They include either an enriched formula of essential amino acids or a commercial protein — only an independent lab knows which one Woolf is getting.