This case series reviews the experiences of three diabetic patients treated at the Intensive Dietary Management clinic in Toronto. All patients were male, ages 40 to 67, with long-term diabetes (10 to 25 years), and all were receiving multiple diabetic medications, including insulin, at baseline. Each patient agreed to follow an intermittent fasting protocol (two patients completed alternating-day 24-hour fasts, while the third followed a triweekly 24-hour fast schedule) in which, in addition to fasting, all meals consumed were directed to be low-carbohydrate to minimize glucose and insulin response. On fasting days, patients only ate dinner; on non-fasting days, they ate lunch and dinner. This protocol was explained during a six-hour nutritional training seminar at study initiation, and patient follow-up visits occurred every two weeks thereafter. Patient 1 followed this diet for seven months, while patients 2 and 3 followed it for 11 months.
The HbA1C responses of patients 1 (40 y/o, T2D for 20 yrs, baseline HbA1C 11), 2 (52 y/o, T2D for 25 yrs, baseline HbA1C 7.2), and 3 (67 y/o, T2D for 10 yrs, baseline HbA1C 6.8) are provided in the figures below.
All three patients were able to discontinue insulin less than a month after beginning the regimen, with patient 1 discontinuing insulin five days after therapy began. All patients also saw a decrease in other diabetic medications, with patients 2 and 3 discontinuing all medication and patient 1 discontinuing three out of four medications. HbA1C decreased from 11% to 7%, 7.2% to 6%, and 6.8% to 6.2% in patients 1, 2, and 3, respectively. All patients lost at least 10 kg.
All patients found the diet tolerable and gave positive assessments of how they felt: Patient 1 felt “excellent” on fasting days, patient 2 felt “terrific,” and patient 3 found fasting “easy” and reported higher energy levels.
Overall, the case series illustrated that an intermittent fasting regimen, paired with a low-carbohydrate diet on non-fasting days, can lead to significant improvements in blood glucose levels (as measured by HbA1C) and diabetic condition (as evidenced by the observed reduction in medication), even in long-term diabetics. Future research could build on this by testing different fasting and patient engagement protocols to identify the most efficacious methods for using fasting to control and reverse diabetes.
Therapeutic fasting as a potential effective treatment for type 2 diabetes