Intermittent Fasting for Older Adults: Is It Safe?
Intermittent fasting for older adults: the US NIA says there is not enough evidence to recommend fasting diets. What to ask your clinician first.
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- Blimbi Editorial
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Editorial review against cited sources, not medical review. Educational, not medical advice.
In 30 seconds
If you are over 60, talk with a healthcare provider before trying intermittent fasting and make sure your eating pattern still provides safe nutrition. The US National Institute on Aging says evidence is insufficient to recommend any fasting diet, with effectiveness and safety especially uncertain in older adults. Most human trials enrolled adults aged 60 or younger.
- The National Institute on Aging says there isn't enough evidence to recommend any fasting diet, and that much more needs to be learned about safety, especially in older adults.
- Most trials enrolled adults aged 60 or younger, and much of the research on aging comes from animals.
- Any eating pattern you try must still give you a safe level of nutrition; talk with your healthcare provider first.
- Insulin, sulfonylureas and glinides can cause low blood sugar during a fast, diuretics and SGLT-2 inhibitors add dehydration risk, and older adults dehydrate more easily.
What do studies say after 60?
Fasting research has mostly studied younger adults, which leaves people over 60 with few direct answers.
The National Institute on Aging says there is not enough evidence to recommend any fasting diet, and that much more needs to be learned about its effectiveness and safety, especially in older adults; most trials enrolled adults aged 60 or younger.Source 1
Early evidence
A National Institute on Aging overview (2018)
The overview says most human trials of calorie restriction and fasting have been short, done in people with overweight and focused on weight loss rather than aging; the longest lasted 2 years. Trials typically recruited adults aged 60 or younger, so the results don't necessarily apply to people older than 60.Source 1
Much of the interest in fasting and aging comes from animal research. To judge studies for yourself, see how to read fasting research.
NIA notes that most relevant studies have been done in laboratory and animal models, and that these findings do not necessarily apply to humans.Source 1
What about muscle, bone and nutrition?
The closest human data on muscle and bone come from calorie restriction, not fasting, in adults under 60.
In the 2-year CALERIE calorie-restriction trial in young and middle-aged adults, bone density, lean body mass and aerobic capacity fell slightly, generally no more than expected from the weight lost; NIA says clinical monitoring is recommended.Source 1
Whatever you try, two basics come first: food that still meets your needs and a conversation with someone who knows your health.
Talk with a healthcare provider about the benefits and risks before starting a fasting plan, and make sure any eating pattern you try still gives you a safe level of nutrition.Source 1
What should you ask before starting?
| Question to ask | Why it matters |
|---|---|
| Is there evidence for people my age? | NIA: not enough evidence to recommend any fasting diet; trials typically recruited adults aged 60 or younger |
| Will I still get safe nutrition? | NIA: any eating pattern you try must still give you a safe level of nutrition |
| Do my medicines lower blood sugar? | NIDDK: with insulin, sulfonylureas or glinides, fasting can cause low blood sugar, so doses need a plan |
| Do I take diuretics or SGLT-2 inhibitors? | NIDDK: they increase fluid loss and add dehydration risk |
| How will I stay hydrated? | NHS: older adults are more at risk of dehydration and should get plenty of fluids |
Who needs a clinician-made plan?
Talk to a qualified health professional before fasting if you are pregnant or breastfeeding, under 18, living with or recovering from an eating disorder, have diabetes, take insulin or a medicine affected by meal timing, are an older adult, or are acutely ill. Do not change the dose or timing of any medicine without your clinician. See Blimbi’s safety guide.
Frequently asked questions
Is intermittent fasting safe for older adults?
Safety is uncertain. The National Institute on Aging says long-term safety and benefit remain unclear and that trials typically recruited adults aged 60 or younger. Talk with a healthcare provider before starting.Source 1
How should an older adult start if they want to try fasting?
Start by talking with your healthcare provider about the benefits and risks, your medicines and your nutrition; the National Institute on Aging stresses that any eating pattern you try must still give you a safe level of nutrition.Source 1
Who should avoid intermittent fasting?
The National Institute on Aging says there is not enough evidence to recommend any fasting diet to the public and advises talking with your provider before any major change. If you take insulin or other diabetes medicines, diuretics or SGLT-2 inhibitors, fasting needs a clinician-supervised plan because of low blood sugar and dehydration risks.Source 1Source 2
Sources
Calorie restriction and fasting diets: What do we know?National Institute on Aging. National Institute on Aging, August 14, 2018.Official guidance
Fasting Safely with DiabetesMartin M. Grajower. National Institute of Diabetes and Digestive and Kidney Diseases, August 26, 2020.Official guidance
DehydrationNHS. NHS, May 1, 2026.Official guidance