Lifestyle therapy is an integral part of type 2 diabetes (T2D) management, but there remains no consensus on an optimal diet. The objective of this study is to evaluate the efficacy of therapeutic fasting as a treatment for T2D. This case follows a male T2D patient treated at the Intensive Dietary Management Clinic in Scarborough, Ontario, over a 4-month period. The patient’s initial fasting regimen consisted of a 24-h fast, three times a week. Over the course of treatment, the patient gradually extended his fasting period, eventually fasting for 42 h, two to three times a week. By the end of treatment, the patient’s weight was reduced by 17.8% and his waist circumference was reduced by 11.0%. In addition, the patient’s glycated haemoglobin levels decreased from 7.7% to 7.2%, and he was able to completely discontinue his insulin treatment, despite over a decade of insulin usage. The patient did not find it difficult to adhere to the fasting schedule and did not experience any hypoglycaemic episodes or other significant adverse effects. These observations suggest that therapeutic fasting may be a viable treatment option for T2D patients.