For people with Huntington’s disease, losing weight can already be a serious concern. So asking them to squeeze all of their meals into a shorter daily window might seem like the last thing researchers would want to try.
But in a small pilot study, 20 adults with early-stage Huntington’s disease were able to follow an eight-hour eating window for 12 weeks without losing weight or lean muscle. Researchers also saw encouraging changes in a measure of disease severity and in a blood marker linked to nerve-cell damage. The study had no control group, however, so it cannot show that time-restricted eating caused those changes or slowed the disease.
The findings, published in Nature Metabolism, are best viewed as an early signal that the approach may be worth testing in a larger randomized trial.
“This is the first time this approach has been formally studied in people with Huntington’s disease,” said lead author Russell Wells, a medical student at Oregon Health & Science University. “We found that participants were able to follow the eating schedule, maintain their weight and show encouraging improvements in clinical and biological measures that are important in Huntington’s disease.”
Huntington’s disease is an inherited condition that gradually affects movement, thinking and emotional regulation. There are currently no approved treatments that have been shown to slow or stop its progression.
Researchers were especially interested in whether time-restricted eating would be practical because weight loss can become a problem as the disease progresses.
Participants chose an eight-hour window that fit their routines, usually starting in the late morning and ending in the early evening. They were encouraged to eat enough during that time to maintain their usual calorie intake.
On average, participants followed the schedule more than five days a week, reported few side effects and kept their weight and lean muscle stable. Most said they adjusted to the schedule within the first couple of weeks.
Researchers also saw a small improvement on a commonly used Huntington’s disease severity score. Blood levels of neurofilament light, a marker that tends to rise as nerve-cell damage increases, fell by an average of 13%.
Those findings are interesting, but they are not proof that the eating pattern changed the course of the disease.
Without a comparison group, researchers cannot rule out other explanations, including normal variation, repeated testing or changes in participants’ behavior outside the eating window. The study was also very small and lasted only 12 weeks.
The team measured changes in how participants’ blood cells handled energy as well, but those findings are still exploratory. They do not show what was happening in the brain or whether participants’ disease was progressing more slowly.
For now, the clearest result may be the most practical one: people with early Huntington’s disease were generally able to follow the eating schedule without the unwanted weight loss researchers had worried about.
“When Russell first brought me the idea, I was skeptical,” said senior author Amie Hiller, professor of neurology at OHSU. “Weight loss is a major challenge for many people with Huntington’s disease, so asking them to eat within a limited time window seemed counterintuitive.”
The findings do not mean people with Huntington’s disease should start intermittent fasting on their own. Maintaining adequate nutrition and body weight can be especially important with the condition, and participants in this study were monitored throughout the intervention.
Researchers are now seeking funding for a larger randomized trial that would compare time-restricted eating with usual eating habits. That kind of study is needed to determine whether the early changes seen here are truly caused by meal timing and whether they last.
The research was supported by an OHSU Parkinson Center of Oregon pilot award, the U.S. Department of Veterans Affairs, the Parkinson’s Disease Research, Education and Clinical Center at the VA Portland Health Care System and the National Center for Advancing Translational Sciences at the National Institutes of Health.