Time-Restricted Eating Shows Promise for Metabolic Syndrome in 3-Month Trial

Pam Taub, MD
Credit: UC San Diego Health

For patients with metabolic syndrome, time-restricted eating could be an effective way to improve overall health, with a new trial suggesting it was associated with improvements in numerous marks of glycemic control and cardiometabolic health.

“There is an urgent need for more effective treatment options that are accessible, affordable and sustainable for the average American,” said Pam Taub, MD, cardiologist and director of the Step Family Foundation Cardiovascular Rehabilitation and Wellness Center at UC San Diego Health² “Our research demonstrates that lifestyle interventions, such as time-restricted eating, can have a meaningful impact on the trajectory of a person’s overall health.”

As US health systems continue to grapple with a growing epidemic of obesity and metabolic diseases, a renewed focus has emerged surrounding the identification and optimization of lifestyle interventions in chronic disease. Citing a lack of concrete evidence on the topic, Taub and colleagues from UC San Diego and the Salk Institute, with funding from the National Institutes of Health, launched the TIMET study to test the feasibility of a long-term study on the same topic.^1,2

For inclusion in the trial, patients needed to be 18 years of age or older, have a BMI of 25 kg/m2 or greater but equal to or less than 41 kg/m2, have a diagnosis of metabolic syndrome, and elevated fasting glucose of between 5.56 and 6.95 mmol/L or HbA1c between 5.7% and 7.0%.¹

“Our bodies actually process sugars and fats very differently depending on the time of day,” said study investigator Satchidananda Panda, PhD, professor at the Salk Institute.² “In time-restricted eating, we are re-engaging the body’s natural wisdom and harnessing its daily circadian rhythms to restore metabolism and improve health."

At the first trial visit, baseline screening assessments were conducted. During these assessments, investigators obtained information from or related to fasting blood draw, blood pressure, height, weight, waist circumference, and questionnaires. Per trial protocol, all participants were outfitted with a continuous glucose monitor and actigraphy device.¹

Following a second visit where patients completed additional baseline assessments, including a 24-hour dietary recall, participants were randomized 1:1 to a standard of care group or the time-restricted eating group for 3 months. Those randomized to standard of care were advised to follow a healthy lifestyle and given nutritional advice such as following a Mediterranean diet. The time-restricted eating group received the same lifestyle and nutritional recommendations but were also assigned a personalized 8- to 10-hour eating window.¹

Of note, the time-restricted eating group received no mandate related to calorie reduction and all participants logged their meals using the myCircadianClock mobile app.¹

In total, 108 participants completed the intervention. This cohort had a mean baseline age of 59 years, mean BMI of 31.22 kg/m2, and a mean eating window of 14.19 hours, and 51.85% were women. Investigators pointed out the time-restricted eating group was younger (56.78 years [SD, 11.34] years vs 61.43), but the groups were similar in terms of baseline levels of glycemic regulation and medication use.¹

Results suggested adherence to time-restricted eating was associated with an improvement in HbA1c, which was the trial’s primary outcome. Specifically, randomization to the time-restricted diet was associated with a 1.7% relative reduction in HbA1c, with a net between-group difference of -0.10% (95% CI, -0.19% to -0.003%). Investigators also highlighted secondary and exploratory analyses of body composition and cardiometabolic risk factors suggested the benefits of time-restricted eating seen in regard to these outcomes were consistent with those seen with glucose regulation and tended to favor time-restricted eating.¹

“Metabolic syndrome, especially when paired with prediabetes, represents a critical tipping point in which the risk for developing type 2 diabetes and heart disease is greatly increased,” add Taub, who also serves as a professor of medicine at UC San Diego School of Medicine.² “We’re hopeful the findings of this study can help others who are looking to address their metabolic syndrome and reduce their risk for type 2 diabetes.”

References:

1. Manoogian ENC, Wilkinson MJ, O'Neal M, et al. Time-Restricted Eating in Adults With Metabolic Syndrome : A Randomized Controlled Trial. Ann Intern Med. Published online October 1, 2024. doi:10.7326/M24-0859
2. UC San Diego. Study: Time-restricted eating may improve health of adults with metabolic syndrome. Newswise. September 30, 2024. Accessed October 8, 2024. https://www.newswise.com/articles/study-time-restricted-eating-may-improve-health-of-adults-with-metabolic-syndrome.