Quick answer: Insulin is a hormone made by the pancreas that moves glucose into cells and promotes fat storage. On keto, low carbohydrate intake keeps blood sugar and insulin lower, which allows stored fat to be released and turned into ketones. Lower insulin demand may also improve insulin sensitivity in some people.
Key takeaways
Insulin helps cells absorb glucose after a meal and signals the body to store extra energy.
With fewer carbohydrates, insulin stays lower, which allows stored fat to be released and used for fuel.
Anyone taking insulin or other glucose-lowering medication can develop low blood sugar on keto, so medication changes belong with their doctor.
What insulin does
Beta cells in the pancreas release insulin when blood sugar rises after a meal. Insulin helps cells absorb glucose and signals the body to store extra energy as glycogen and fat.
Insulin on a ketogenic diet
With fewer carbs, blood sugar and insulin stay lower. That allows fat to be released and used for fuel and ketone production. See how keto works.
Insulin sensitivity
Insulin resistance means cells respond poorly to insulin, so the pancreas makes more. Lowering carbohydrate load may improve insulin sensitivity for some people. See keto and metabolic function.
Important safety note
If you take insulin or other glucose-lowering medication, starting keto can cause low blood sugar. Medication changes must be made with your doctor.
Healthy aging lens
Insulin resistance is linked to many age-related conditions. Steadier blood sugar supports healthy aging. Related: insulin sensitivity and healthy aging.
When to see a naturopathic doctor
It may be time to see a naturopathic doctor if you have diabetes or take insulin, sulfonylureas or SGLT2 inhibitors (risk of low blood sugar or ketoacidosis), or if you take blood pressure medication or diuretics. The same is true if you have kidney, liver, gallbladder or pancreas disease, or high cholesterol, if you are pregnant, breastfeeding, or have a history of disordered eating, or if you want a keto plan tailored to your labs and goals.
See a medical provider promptly for nausea and vomiting, abdominal pain, confusion, fruity-smelling breath with rapid breathing, or very high blood sugar or ketone readings, which can signal ketoacidosis.
Want a keto plan that’s safe for your health?
A free 15-minute consultation with Dr. Kneessi. No cost, no obligation. In-office in Odenton, MD or by telehealth.
Questions to bring to your clinician
These questions can help you get the most out of your next visit.
If I start keto, how should my blood sugar medication be monitored or adjusted?
Could any of my current medications or supplements interact with the options discussed here?
Would any lab testing add useful information in my situation, or is it reasonable to start with daily habits?
Which one or two changes would be most worthwhile for me to focus on first?
Frequently asked questions
Why does insulin drop on keto?
Because fewer carbohydrates means less glucose entering the blood.
Does keto improve insulin resistance?
It may for some people; results vary.
Can I do keto if I take insulin?
Only with close medical supervision.
What is insulin’s role in fat storage?
It signals the body to store extra energy as fat.
Sources
- Dimitriadis G, et al. Insulin effects in muscle and adipose tissue. Diabetes Res Clin Pract 2011. PMID: 21864752. https://pubmed.ncbi.nlm.nih.gov/21864752/
- Saltiel AR, Kahn CR. Insulin signalling and the regulation of glucose and lipid metabolism. Nature 2001. PMID: 11742412. https://pubmed.ncbi.nlm.nih.gov/11742412/
- Boden G, et al. Effect of a low-carbohydrate diet on appetite, blood glucose levels, and insulin resistance in obese patients with type 2 diabetes. Ann Intern Med 2005. PMID: 15767618. https://pubmed.ncbi.nlm.nih.gov/15767618/
- Cucuzzella M, Riley K, Isaacs D. Adapting Medication for Type 2 Diabetes to a Low Carbohydrate Diet. Front Nutr 2021. PMID: 34434951. https://pmc.ncbi.nlm.nih.gov/articles/PMC8380766/
- Facchini FS, et al. Insulin resistance as a predictor of age-related diseases. J Clin Endocrinol Metab 2001. PMID: 11502781. https://pubmed.ncbi.nlm.nih.gov/11502781/
- NIDDK: Insulin Resistance & Prediabetes
- MedlinePlus: Insulin in Blood
This article is for educational purposes only and is not medical advice. It does not replace an individual evaluation. Talk with your healthcare provider before starting supplements or changing medications, especially if you are pregnant, nursing, or managing a health condition.
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