Time-Restricted Eating Could Improve Metabolic Health in Type 2 Diabetes

As debate around the efficacy of various dietary regimens continues, new research into the impact of a time-restricted eating protocol details the potential metabolic benefits of such an approach in adult patients with type 2 diabetes.

A randomized crossover trial assessing a 3-week time-restricted eating regimen, which restricted intake to a 10-hour period, compared to a control regimen, results of the study suggest adherence to time-restricted eating was associated with a reduction in 24-hour glucose levels and a nearly 3-hour increase in mean time spent in normal glucose range.

“Time-restricted eating is a novel strategy to improve metabolic health and has been proposed to counteract the detrimental effects of eating throughout the day by limiting food intake to daytime hours. To date, only a few studies have examined the metabolic effects of time-restricted eating in adults with type 2 diabetes,” wrote investigators.

As major organizations, accrediting bodies, and educational institutions begin to emphasize the role of nutrition in disease management, research interest in dietary regimens has grown in tandem. The current study, which was led by investigators from the NUTRIM School of Nutrition and Translational Research in Metabolism at Maastricht University Medical Center, was designed to test the investigators’ hypothesis that impairments in metabolic rhythmicity in adults with type 2 diabetes were due to a disturbed-eating fasting cycle and adherence to a time-restricted eating regimen might improve metabolic health beyond purported benefits in weight loss.

As such, the study was designed as a randomized crossover study to co [pare the effect of limiting food intake to a f10-hour daily time frame for 3 weeks in free-living conditions on hepatic glycogen utilization and insulin sensitivity in adults with type 2 diabetes. Conducted between April 2019 and February 2021, the study enrolled 14 adults with type 2 diabetes. The patients had a mean age of 67.5±5.2 years, 50% were female, and the mean HbA1c was 6.4±0.7% at baseline.

As part of the study protocol, during the 3-week time-restricted eating intervention, participants were instructed to consume their typical diet within a 10-hour window during the daytime, with the last meal completed no later than 18:00 hours. In the control arm, volunteers were instructed to consume their typical diet over at least a 14-hour period each day. Investigators noted all patients received a continuous glucose monitoring device at the start of each intervention period. In addition to hepatic glycogen levels and insulin sensitivity, the study also included multiple other outcomes of interest, including glucose homeostasis, 24-hour energy expenditure, substrate oxidation, hepatic lipid content, and skeletal muscle mitochondrial capacity.

Upon completion of the trial, results indicated hepatic glycogen contentment was similar between the time-restricted eating and control regimens (0.15±0.01 vs 0.15±0.01 arbitrary units; P=.88) and there was no significant impact on M value with time-restricted eating compared to the control regimen (19.6±1.8 vs 17.7±1.8 μmol kg−1 min−1; P=.10). Additionally, results suggested there was no significant impact on both hepatic and peripheral insulin sensitivity with time-restricted eating (P=.67 and P=.25, respectively).

However, investigators pointed an increase was observed for insulin-induced non-oxidative glucose disposal with time-restricted eating compared to the control regimen (4.3±1.1 vs 1.5±1.7 μmol kg−1 min−1; P=.04). Further analysis also revealed time-restricted eating was associated with increased time spent in the normoglycemic range (15.1±0.8 vs 12.2±1.1 hours per day; P=.01) as well as decreases in fasting glucose (7.6±0.4 vs 8.6±0.4 mmol/l; P=.03) and 24-hour glucose levels (6.8±0.2 vs 7.6±0.3 mmol/l; P <.01). Investigators noted that while energy expenditure during a 24-hour period was not impacted, a decrease in 24-hour glucose oxidation was observed with time-restricted eating (260.2±7.6 vs 277.8±10.7 grams per day; P=.04)

“Despite the lack of changes in hepatic glycogen and insulin sensitivity, we did find that our 10-hour time-restricted eating protocol decreased 24-hour glucose levels in individuals with type 2 diabetes, primarily driven by decreased nocturnal glucose levels,” wrote investigators. “Notably, time-restricted eating also lowered overnight fasting glucose, increased the time spent in the normal glucose range and decreased time spent in the high glucose range, all of which are clinically relevant variables in type 2 diabetes.”

This study, “Three weeks of time-restricted eating improves glucose homeostasis in adults with type 2 diabetes but does not improve insulin sensitivity: a randomised crossover trial,” was published in Diabetologia.