Metabolic syndrome raises the risk of heart disease, stroke, and type 2 diabetes for many Americans. A recent clinical trial highlights how three months of time-restricted eating enhanced participants’ blood sugar management and overall metabolic health, potentially helping to prevent severe chronic illnesses.
Over one-third of adults in the United States are affected by metabolic syndrome, a combination of risk factors that significantly increase the likelihood of heart disease, stroke, and type 2 diabetes. These risk factors include hypertension, high blood sugar levels, excess fat around the abdomen, and unhealthy cholesterol levels.
A recent clinical study by researchers from the Salk Institute and the University of California San Diego School of Medicine has revealed that time-restricted eating, also referred to as intermittent fasting, may provide substantial health benefits for adults suffering from metabolic syndrome. Participants who followed a consistent eating schedule within an eight-to-ten-hour timeframe each day for three months demonstrated better blood sugar regulation and improved metabolic function compared to those on standard treatments.
“Our bodies process sugars and fats differently throughout the day,” explains Salk Professor Satchidananda Panda, a co-author of the study. “Time-restricted eating allows us to tap into the body’s inherent rhythm and optimize our metabolism and overall health.”
The TIMET study is the first of its kind to explore the advantages of a personalized time-restricted eating plan for patients undergoing medication for metabolic syndrome. The findings were published on September 30, 2024, in the journal Annals of Internal Medicine.
“For numerous patients, metabolic syndrome is a critical point that can lead to severe and chronic conditions like diabetes and heart disease,” states co-author Pam Taub, a professor of medicine and cardiologist at the UC San Diego School of Medicine. “We urgently need more effective lifestyle changes that are practical, affordable, and long-lasting for average Americans.”
The Western diet, which is high in sugar, salt, and unhealthy fats, along with increasingly inactive lifestyles, is believed to have contributed to the growing rates of metabolic disorders. Although the common advice is to “consume less and exercise more,” sustaining these lifestyle modifications over time can be challenging for many. The researchers propose that time-restricted eating provides a more feasible lifestyle adjustment available to a broader group of patients, including those already on medication.
“In contrast to expensive medications like Ozempic, which often require a lifetime commitment, time-restricted eating is a straightforward lifestyle modification with no side effects and can be maintained permanently,” remarks Emily Manoogian, the first author and a staff scientist in Panda’s lab at Salk. “Patients appreciate the flexibility of changing when they eat rather than what they eat.”
The study customized time-restricted eating plans to align with each participant’s eating patterns, sleep schedules, and personal obligations. This means they adjusted their eating hours to a consistent eight to ten hours daily, starting at least an hour after waking and finishing at least three hours before sleep. Manoogian mentions that this tailored approach made it easier for patients to adhere to the program compared to other intermittent fasting studies that typically assign the same scheduling to all participants.
The TIMET study also included participants who were on medication for metabolic syndrome—a group often excluded from such research. This makes it the first investigation to assess the effects of time-restricted eating alongside standard pharmacological treatments.
In the trial, 108 adults with metabolic syndrome were randomly assigned to either the time-restricted eating group or a control group. Both groups received ongoing standard treatments and engaged in nutritional counseling focused on the Mediterranean diet. Participants also tracked their meals using the myCircadianClock app, developed at Salk.
After three months, those participating in the time-restricted eating regimen showed enhancements in critical markers of cardiometabolic health, such as blood sugar levels and cholesterol. They also experienced lower levels of hemoglobin A1c, an indicator of long-term blood sugar control, achieving reductions comparable to those seen in more intensive interventions offered by the National Diabetes Prevention Program.
Members of the time-restricted eating group reported greater reductions of about 3-4% in body weight, body mass index (BMI), and abdominal trunk fat, a type of fat closely associated with metabolic disorders. Notably, these participants did not face significant loss of lean muscle mass, which is often a concern during weight loss efforts.
The TIMET trial contributes to the increasing evidence that time-restricted eating serves as a practical, economical method to enhance cardiometabolic health. The encouraging outcomes suggest healthcare professionals might consider recommending this lifestyle intervention to patients with metabolic syndrome as a supplemental approach to existing treatments, although further long-term studies are necessary to assess whether time-restricted eating can maintain its advantages and ultimately diminish the risk of chronic illnesses.
Additional authors include Monica O’Neal, Kyla Laing, and Nikko R. Gutierrez from Salk, along with Michael J. Wilkinson, Justina Nguyen, David Van, Ashley Rosander, Aryana Pazargadi, Jason G. Fleischer, and Shahrokh Golshan from UC San Diego.
This research received support from the National Institutes of Health (R01DK118278, R01CA258221, P30CA014195, UL1TR001442), the Robert Wood Johnson Foundation (76014), and the Larry L. Hillblom Foundation Postdoctoral Fellowship.
