Three Insulin-Dependent Type 2 Diabetes Patients Stopped Insulin Using Intermittent Fasting: What the Research Shows

Medical disclaimer: This article summarises published research for informational purposes only. It is not medical advice and is not a substitute for guidance from a qualified health professional. Always consult your doctor before starting any fasting protocol, especially if you have an existing health condition or take medication.

Study at a Glance

What This Study Looked At

Clinicians at a Toronto-based diabetes management program wanted to document what happened when long-term, insulin-dependent type 2 diabetes patients adopted structured intermittent fasting protocols under medical supervision. All three patients had been on insulin therapy for years, with little expectation of ever coming off it. The case series asks a question with real relevance to anyone fasting for insulin resistance or blood sugar control: can intermittent fasting meaningfully reduce or eliminate the need for insulin in long-standing type 2 diabetes?

This was not a randomized trial — it is a clinical case series, the type of report used to document a striking, novel, or unexpected outcome in a small number of real patients, usually as a precursor to larger controlled studies.

Who Was Studied

Participant profile: Three male patients, middle-aged to older adult (approximate ages in their 40s, 50s, and 60s), each with a long history of type 2 diabetes (roughly 10–25 years) and each dependent on daily insulin injections, in some cases alongside oral hypoglycemic medication, at the time the fasting protocol began.

How the fasting protocol worked: Under physician supervision, each patient adopted a therapeutic fasting regimen involving either three 24-hour fasts per week or a daily extended fasting window. On fasting days, patients consumed low-carbohydrate meals only within a restricted window, or no calories at all for 24 hours, with medication doses adjusted downward in real time to avoid hypoglycemia as blood sugar control improved.

What the Researchers Found

Insulin Discontinuation

• All three patients were able to stop insulin therapy entirely after starting the supervised fasting protocol — a notable outcome given each had been insulin-dependent for years
• Oral diabetes medications were also reduced or discontinued in each case over the following months
• Blood glucose control was maintained or improved despite the removal of insulin

Weight and Body Composition

• All three patients lost a substantial percentage of body weight over the follow-up period, with reported losses in the broad range of roughly 10–18% of starting body weight
• Waist circumference also decreased notably in each case, consistent with reduced visceral fat

What Did Not Change

• No episodes of severe hypoglycemia were reported once medication doses were appropriately titrated down alongside the fasting protocol
• Patients were able to maintain daily activities and work responsibilities throughout the fasting periods

What the Researchers Concluded

The authors concluded that therapeutic intermittent fasting, implemented with physician supervision and real-time medication adjustment, allowed long-term insulin-dependent type 2 diabetes patients to discontinue insulin therapy while maintaining glycemic control — suggesting fasting protocols deserve further study as a potential alternative to escalating insulin doses in type 2 diabetes management.

What This Means If You Fast

• This is not a green light to stop insulin on your own. Every patient in this case series was medically supervised, with medication doses adjusted in real time by a physician. Reducing insulin without supervision while fasting can cause dangerous hypoglycemia.
• Fasting's blood sugar benefits are consistent with broader research. This case series lines up with the wider evidence base showing intermittent fasting improves insulin sensitivity, even though this particular report involves just three patients.
• Weight loss and glycemic improvement often move together. The substantial weight loss seen in all three cases likely contributed meaningfully to the reduced insulin requirement, alongside the direct metabolic effects of fasting itself.
• Long-standing diabetes doesn't rule out major improvement. These patients had been diabetic and insulin-dependent for a decade or more — a population often assumed to have limited room for reversal. This report challenges that assumption, cautiously.
• If you're on any glucose-lowering medication and considering fasting, loop in your doctor before you start. Medication timing and dosing often need to change alongside a new fasting pattern, exactly as it did for these three patients.

Study Limitations

• Extremely small sample size (n=3) — case series findings cannot be generalized to the broader population of people with type 2 diabetes
• No control group, so it's impossible to separate the effect of fasting from other lifestyle changes patients may have made simultaneously
• All patients were male, so findings may not translate directly to women with type 2 diabetes
• Medical supervision and individualized medication titration were central to safety in this report — an unsupervised version of this approach carries real hypoglycemia risk
• As a case series, this is one of the lowest tiers of clinical evidence and should be interpreted as hypothesis-generating rather than conclusive
• Long-term durability beyond the reported follow-up period is unknown

Source

Furmli S, Elmasry R, Ramos M, Fung J. Therapeutic use of intermittent fasting for people with type 2 diabetes as an alternative to insulin. BMJ Case Reports. 2018. PMID: 30297354

Frequently Asked Questions

Can intermittent fasting really help you stop taking insulin?

In this case series, all three long-term insulin-dependent patients were able to discontinue insulin under physician supervision after starting a structured fasting protocol. This is a promising signal from a small report, not proof that fasting will work the same way for everyone on insulin.

Is it safe to stop insulin while fasting without talking to a doctor?

No. Every patient in this case series had their medication supervised and adjusted by a physician throughout the process. Stopping or reducing insulin without medical guidance while fasting can cause dangerous low blood sugar (hypoglycemia).

How long did it take for these patients to come off insulin?

It varied — one patient came off insulin within days of starting the fasting protocol, while others took a few weeks to about a month, as their fasting pattern became consistent and their blood sugar control improved.

How much weight did the patients in this study lose?

All three patients lost a substantial share of their body weight, in the broad range of roughly 10–18%, over their respective follow-up periods, alongside notable reductions in waist circumference.

Does this study apply to people with type 1 diabetes?

No. This case series involved type 2 diabetes patients only. Type 1 diabetes involves an inability to produce insulin at all, and fasting protocols carry very different — and generally higher — risks for insulin dosing in that population; medical supervision is essential.

Related Research and Articles

• How intermittent fasting improves insulin sensitivity
• Intermittent fasting for women with type 2 diabetes
• Fasting and inflammation: what women should know
• Does intermittent fasting slow your metabolism?
• What is the 16:8 intermittent fasting protocol?

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