Time-restricted eating for as little as three weeks in type 2 diabetes improves glucose homeostasis but does not affect insulin sensitivity
A time-restricted eating (TRE) pattern which limits intake of food to a 10-hour window can improve glucose homeostasis but not insulin sensitivity according to the results of a randomised, cross-over trial by Dutch researchers.
Any changes to the day–night rhythm due, for example, to shift work and subsequent changes in eating patterns is associated with body weight gain and impaired glucose tolerance. Moreover, some data also indicate that night shift work, especially rotating shift work, is associated with higher risk of type 2 diabetes. Time-restricted eating could have health benefits and some evidence for this arose from a study which found that the daily duration of food intake exceeded 14.75 hour for half of the cohort. As part of this study, when researchers asked overweight individuals with a >14 hr eating duration, to restrict food intake to only 10-11 hours per day for 16 weeks, they reduced body weight and reported higher levels of energy and had improved sleep. Other work has revealed how TRE improves 24-hour glucose levels and among men with pre-diabetes, whereas the use of a 12-hour TRE pattern improved insulin sensitivity, β cell responsiveness, blood pressure, oxidative stress, and appetite. But whether a time-restricted eating regime could benefit those with type 2 diabetes remains unclear, although in one feasibility study, it was found that a TRE regime did not significantly improve measures of glycaemic control or reduce body mass. Despite this, the effect of TRE on other metabolic health parameters is largely unknown and was the subject of the present study.
The Dutch team recruited adults with type 2 diabetes and a HbA1C of 6.4% and asked them to participate in a 10-hour TRE regime for 3 weeks in comparison to a control group whose food intake was spread over a period of > 14 hours/day and then the TRE group crossed-over after a 4 week wash-out period. Since the liver plays an important role in the regulation of blood glucose and that among those with type 2 diabetes, nocturnal glucose levels are elevated, the authors speculated that a TRE regime might reduce nocturnal glucose levels and therefore improve insulin sensitivity.
Time-restricted eating and glucose levels
A total of 14 adults with a mean age of 67.5 years (50% female) were recruited into the trial.
The mean 24-hour glucose levels were lower among the TRE group compared to controls (6.8 vs 7.6mmol/l, TRE vs control, p < 0.01). However, there were no significant differences with insulin sensitivity (19.6 vs 17.7 mcmol/kg/min, TRE vs control, p = 0.1). There were also no changes in 24-hour energy and substrate metabolism between the two groups, although the time-restricted eating group did spend a significantly longer period of time with blood glucose levels within the normal range (15.1 vs 12.2 hours, TRE vs control p = 0.01).
The authors concluded that TRE provides an additional strategy to maintain 24 hour glucose homeostasis in free-living subjects with type 2 diabetes.
Andriessen C et al. 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 Diabetologia 2022