Continuous glucose monitoring
To reduce the study burden and prevent daily finger pricks, we used a continuous glucose monitoring device (Freestyle Libre 1) to monitor blood glucose, which allowed subjects to perform all normal activities while wearing the sensor. Subjects were taught to subcutaneously implant the CGM sensor and were instructed to extract the data from the sensor at least every 8 h. One week prior to the intervention subjects started to monitor their glucose until one week after the intervention. Compliance among participants was good, with a median 100% (range 76–100%) of data correctly collected, during a median period of 14 (range 11–27) days with a median 1350 (range 1043–2617) sensor readings. During that same period, participants were asked to record their diet using an online food diary (Eetmeter v2019-2020) from the Voedingscentrum)