Intermittent fasting is known to regulate blood glucose and evidence suggests that intermittent fasting can have a beneficial impact on glucose control.

A systematic review of intermittent fasting was undertaken (Vitale & Kim, 2020). “The purpose of this study was to evaluate the effects of intermittent fasting on glycaemic control and body composition in adults with obesity and type 2 diabetes. Although intermittent fasting has shown some promise in improving gluco-regulatory indicators and body composition in adults with obesity, there is currently no systematic review evaluating these effects in adults with obesity and type 2 diabetes.”

“Five studies met inclusion criterion. All studies were RCTs in adult subjects (n = 46-137) with T2DM and a BMI of ≥30 kg/m2. Four different intermittent fasting regimens were reviewed. All fasting regimens revealed strong evidence to support intermittent fasting as a feasible diet to improve glycemia and body composition measures within 12–24 weeks.

Follow-up 12–18 months after intermittent fasting did not show promising results for continued weight loss and improved glycaemic control. Majority of the studies demonstrated insignificant differences between intermittent fasting and continuous energy restriction for measures of Hba1c and body composition. More data on intermittent fasting in adults with obesity and type 2 diabetes was needed to determine its benefits within this patient population.”

“Future research should include consistent fasting regimens and larger sample sizes to improve the reliability and generalizability of the data. Also, consistent follow-up after a fasting intervention may enhance long-term benefits and should be considered in future research.”

This research data on the impact of fasting when continued is backed up by another meta-analysis by Cho et al (2019). “The effectiveness of an IFD was estimated by the weighted mean difference (WMD) for several variables associated with glucometabolic parameters including body mass index (BMI) and fasting glucose.”

“The pooled mean differences of outcomes were calculated using a random effects model. From 2814 studies identified through a literature search, we finally selected 12 articles (545 participants). Compared with a control diet, an IFD was associated with a significant decline in BMI (WMD, −0.75 kg/m2; 95% CI, −1.44 to −0.06), fasting glucose level (WMD, −4.16 mg/dL; 95% CI, −6.92 to −1.40), and homeostatic model assessment of insulin resistance (WMD, −0.54; 95% CI, −1.05 to −0.03).

Fat mass (WMD, −0.98 kg; 95% CI, −2.32 to 0.36) tended to decrease in the IFD group with a significant increase in adiponectin (WMD, 1008.9 ng/mL; 95% CI, 140.5 to 1877.3) and a decrease in leptin (WMD, −0.51 ng/mL; 95% CI, −0.77 to −0.24) levels. An IFD may provide a significant metabolic benefit by improving glycemic control, insulin resistance, and adipokine concentration with a reduction of BMI in adults.”