Time-restricted eating for three weeks in patients with type 2 diabetes improved glucose homeostasis but had no effect on insulin sensitivity
A time-restricted eating (TRE) regime that limits food intake to a 10-hour window, led to improvements in glucose homeostasis but not insulin sensitivity according to the results of a randomised, cross-over trial by Dutch researchers.
Alteration of 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. Furthermore, some data also suggest that night shift work, especially rotating shift work including night shifts, is associated with higher risk of type 2 diabetes. Time-restricted eating may have health benefits particularly given that in one study using a smartphone app, the daily duration of food intake exceeded 14.75 hr for half of the cohort. Interestingly, however, in this smartphone app study, when overweight individuals with a >14 hr eating duration ate for only 10-11 hours per day for 16 weeks, they reduced body weight and reported higher levels of energy and had improved sleep. Moreover, other work has revealed how TRE improves 24-hour glucose levels and among men deemed to have pre-diabetes, whereas the use of a 12-hour TRE pattern improved insulin sensitivity, β cell responsiveness, blood pressure, oxidative stress, and appetite. Nevertheless, 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. As it is known that 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 17.7mcmol/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 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