Eating within 10-h window benefits cardiometabolic health in MetS patients

Time-restricted eating (TRE) has the potential to be a powerful lifestyle intervention that can be used as an adjunct to standard medications in individuals with metabolic syndrome (MetS), with a recent study showing that limiting food intake within 10 hours each day promotes weight loss and improves cardiometabolic health in this population.

“People with MetS are at risk for diabetes and heart disease. Current treatment requires weight loss and lifestyle changes that are challenging; thus, new behavioural interventions are needed,” according to the investigators.

The 10-hour TRE creates a 14-hour nightly fast, aimed at maintaining a consistent daily cycle of feeding and fasting to support robust circadian rhythms, they added. “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. [Science 2016;354:1008-1015]

In the present small pilot study, 19 individuals (mean age, 59 years; 13 men; mean body mass index, 33.06 kg/m²) with MetS and a baseline mean daily eating window of ≥14 hours underwent a TRE intervention that limited dietary intake within a consistent self-selected 10-hour window for 12 weeks. Sixteen (84 percent) of them were taking at least one medication, with most on a statin (79 percent) or an antihypertensive drug (63 percent).

All participants used a validated smartphone application to log their caloric intake during the 2-week baseline and 12-week intervention periods. They also wore a wrist activity monitor and a continuous glucose monitor for 2 weeks to track activity and intestinal glucose levels, respectively.

During the 12-week intervention, the eating window decreased substantially by an average of 28.75 percent, from a mean of 15.13 to 10.78 hours. This occurred in parallel with reductions in mean daily caloric intake (–8.62 percent) despite the absence of recommendations to change dietary quantity or quality. [Cell Metab 2020;31:92-104.e5]

TRE also resulted in significant weight loss (mean, –3.30 kg; p=0.00028), which was accompanied by favourable reductions in percent body fat (mean, –1.01 percent; p=0.00013), visceral fat rating (mean, –0.58; p=0.004) and waist circumference (mean, 4.46 cm; p=0.0097). On mixed linear model analyses, the reduction in waist circumference correlated with changes in weight (p=0.017), eating interval (p=0.005), and combined change in weight and eating interval (p=0.004).

Furthermore, there were significant improvements in atherogenic lipid and blood pressure levels. Specifically, total cholesterol decreased by 7 percent (mean, –13.16 mg/dL; p=0.03), low-density lipoprotein cholesterol by 11 percent (mean, –11.94 mg/dL; p=0.016), nonhigh density lipoprotein cholesterol by 9 percent (mean, –11.63 mg/dL; p=0.04), and systolic and diastolic blood pressure by 4 percent and 8 percent (mean, –5.12 mm Hg; p=0.041 and mean, –6.47 mm Hg; p=0.004), respectively.

There was a trend toward improvement in fasting glucose (mean, –5.7 mg/dL; p=0.081), fasting insulin (mean, –3.6 mIU/mL; p=0.064) and HbA1c (mean, –0.14 percent; p=0.058). Interestingly, participants with elevated fasting glucose (≥100 mg/dL) showed a significant reduction in HbA1c (mean, –0.22 percent; p=0.04).

Effective and totally doable

“In this study of patients with MetS, 63.2 percent were engaged in some amount of TRE at [about] 16 months from the completion of the study intervention, suggesting that lasting effects of the initial intervention on behaviour are feasible,” the investigators noted.

They enumerated three major trends in self-selected eating patterns with TRE that may help to explain the observed benefits in MetS. First, participants were able to maintain a shortened daily eating window and nightly fasting. Second, TRE was accomplished through a combination of moderate delays and advances in meal timing as opposed to skipping meals. Finally, regularity in timing of caloric intake was improved.

“Unlike a 6-h TRE intervention which reported several adverse events including vomiting, headaches, increased thirst and diarrhoea, participants in our 10-h TRE intervention did not report any of these adverse events,” they added. [Cell Metab 2018;27:1212-1221.e3]

The investigators also pointed out that the observed benefits of TRE are additive to the effects of statins and antihypertensive medications. This has important implications in a population at high risk for cardiovascular disease.

“The high level of adherence to [this eating schedule] in our study, no reported adverse effects, and low dropout rate suggest that a self-selected 10-hour window for TRE may be feasible for patients with MetS to adhere to over a longer period of time,” they said.