Restricting Meals to a 10-Hour Window May Help Prevent Diabetes, Heart Disease

Results of a pilot study published Thursday in Cell Metabolism conclude that time-restrictive eating (TRE) can benefit patients with metabolic syndrome (MetS).

MetS is classified as the presence of multiple risk factors, such as abdominal obesity or elevated blood pressure, which can lead to type 2 diabetes or cardiovascular disease (CVD). The syndrome affects roughly 30% of the US population.

The single-arm, paired-sample trial limited self-reported baseline mean eating windows of 14 hours or greater a day to within a strict, self-selected 10-hour window. Reported results included weight loss, lower blood pressure levels, and reduced atherogenic lipids, with no adverse effects. Based on these results, researchers said TRE could be an “add-on” to existing treatments for MetS patients.

Over 12 weeks, 19 participants with MetS limited their food consumption to a self-selected 10-hour window while maintaining previously prescribed treatments. Most of the patients were obese; 16 of the 19 patients were taking at least 1 medication throughout the process, such as a statin or antihypertensive drug.

Patients used an app called myCircadianClock (mCC) to log their caloric intake during a 2-week baseline period and a 12-week testing period.

"Metabolism is closely linked with circadian rhythms, and knowing this, we were able to develop an intervention to help patients with metabolic syndrome without decreasing calories or increasing physical exercise," said Pam Taub, co-corresponding author and associate professor of medicine at the UC San Diego School of Medicine and a cardiologist at UC San Diego Health, in a statement. "If we can optimize circadian rhythms then we might be able to optimize the metabolic system."

According to the study, “TRE led to weight loss, healthier body composition, lower blood pressure and levels of CVD-promoting lipids.” On average, patients lost weight at a healthy rate of roughly 275 grams a week, or a little more than half a pound a week.

Overall, patients in the study lost an average of:

• 3% in body weight
• 4% in waist circumference
• 3% of body mass index
• 3% of body fat
• 3% of visceral fat rating
• 4% of systolic blood pressure
• 8% of lower diastolic blood pressure
• 7% in total cholesterol
• 11% in low-density lipoprotein cholesterol
• 9% in non-high-density lipoprotein cholesterol

Though drastic lifestyle changes such as dieting and increasing physical exercise are often recommended for patients with MetS, these can be difficult to maintain. For this reason patients ultimately end up taking statin and antihypertensive medications as treatment methods.

According to the authors, “there is a critical unmet need for lifestyle interventions in MetS that are effective, easy for clinicians to teach to patients during routine care, and intuitive for patients to adopt and maintain either to prevent or work as an ‘add-on’ to pharmacological treatment.”

The TRE study did not find any patients experienced adverse effects. The authors feel the success is in part attributable to the feasibility of maintaining a 14-hour fasting window over time, increased regularity in caloric intake, and patients’ flexibility in meal timing, as opposed to skipping meals altogether.

“Taking an individual’s schedule and personal preference into consideration and letting the participants choose their own TRE interval are likely important factors for adherence, efficacy, and reducing adverse effects,” stated the authors.

Though there was no aim to decrease overall dietary quantity, researchers found an overall 14.47% decrease in average daily caloric intake compared to the 2-week baseline. Additionally, the participants’ restful sleep time increased by 23% throughout the study.

Due to the small sample size, researchers are hoping to conduct future studies on in the impact of TRE on patients with MetS. With the availability of a user-friendly smartphone app, researchers are hopeful patients can be monitored remotely over long periods of time in follow-up studies.

References

Wilkinson MJ, Manoogian ENC, Zadourian A, et al. Ten-hour time-restricted eating reduces weight, blood pressure, and atherogenic lipids in patients with metabolic syndrome [published online December 5, 2019]. Cell Metab. doi: 10.1016/j.cmet.2019.11.004.