SIMPLE’s expert guide on intermittent fasting for seniors

Written by Aly Owen

Medically reviewed by Louise Bula, RD

Published on March 18, 2024 | Updated on March 28, 2024

Aging is a beautiful privilege that not everyone gets to have. 

That doesn’t mean it always feels like a piece of cake, however. Sometimes, it’s something you’d rather not stomach at all. Other times, that cake — while welcome in some ways — just ushers in other unwanted guests.

While there are a lot of benefits to getting older, your mind and body may naturally face changes and new challenges that threaten to rain on your parade. 

That’s where intermittent fasting comes in: it may not be able to stop the rain altogether, but it might be just the umbrella you were looking for to soften its impact and protect you from those not-so-fun elements during the journey. 

Whether you’re considering intermittent fasting over 50, intermittent fasting over 60, or intermittent fasting over 70, let’s take a look at the what, the why, and the how of intermittent fasting for older adults and the best intermittent fasting schedules for seniors. 

If we lost you at “intermittent fasting,” you might want to check out our guide on intermittent fasting for beginners before getting into the specifics of intermittent fasting for seniors!

Is intermittent fasting OK for seniors? 

In general, intermittent fasting is safe for people ages 18–80, but everyone is different. No matter what age you are (or feel!), “Is intermittent fasting safe?” always has to be answered on an individual basis. Plus, intermittent fasting for women over 60 may involve different considerations than, say, intermittent fasting for men over 50 or intermittent fasting for women over 70. 

Likewise, while there have been some studies that investigate how fasting affects older adults,[3] many larger-scale studies focus on younger or middle-aged adults, so we need more specific studies on older age groups. 

That said, research so far has shown that intermittent fasting for older adults can be not only safe but also beneficial.[3] More on that later. 

The individual variability in fasting responses and results is why we always recommend consulting your primary care provider before making any significant changes to your eating habits or lifestyle — especially if you’re on medications or have existing health conditions (like type 1 diabetes, disordered eating, or anything that affects your thyroid).  

If they’re on board but you’re not sure where to start, we can help! From the pros and cons of intermittent fasting plans to tips on how to get lasting results without compromising your well-being, we can offer personalized advice tailored to your unique goals and needs. Take our SIMPLE quiz to get started. 

Why intermittent fasting might affect younger and older adults differently

Everyone experiences aging differently, and a number definitely isn’t indicative of a certain state of being. Just ask the 20-something with terrible back pain and the 70-something who plays bi-weekly competitive tennis. 

So, why might intermittent fasting hit differently for older adults? 

Two reasons: 

1. nutrient needs
2. hormone levels

Much like a child needs extra nutrients to develop, older adults need extra nutrients [4] — like protein, calcium, vitamin D, and fiber — to continue to thrive. That means intermittent fasting for senior women, men, and non-binary folks might be more likely to lead to nutrient deficiencies if they aren’t extra attentive to getting everything they need during their eating windows. 

On the hormone front, people over 50 will be producing less of certain hormones, like estrogen, progesterone, and androgens.[5] These hormones aren’t just attached to reproductive or sexual functions; they also play roles in things like bone development, muscle retention, metabolism, and mental sharpness.[6–9] 

Some research suggests intermittent fasting may decrease the production of certain hormones, which means older adults who fast may end up with even less of these hormones.[10] It also suggests that intermittent fasting for women over 50 may have different results than intermittent fasting for men over 50 since a reduction in androgens could be beneficial for some women but detrimental to men. It’s worth noting that these are just some preliminary findings, and more research is required in the area (including around the effects of fasting on trans men and women and people on hormone replacement therapy). 

For more insight into how potential fasting effects and considerations change as we get older, check out our intermittent fasting by age chart. 

Benefits of intermittent fasting for seniors 

It may not be able to turn back time in a literal sense, but intermittent fasting offers several potential benefits that can keep you fit and fight from your head to your toes as you age. 

Reduce the risk of heart disease 

Heart disease is the leading cause of death for people 65 and older.[11] Intermittent fasting can support heart health by improving cardiovascular risk markers (like lowering systolic blood pressure and cholesterol [12,13]).[14,15]

Support weight loss and fat loss

Quite a bit of research connects intermittent fasting to various physiological benefits that could individually or collectively lead to body weight loss and belly fat loss.[16–18]

Reduce the risk of type 2 diabetes

More than 25% of the US population of adults 65 and older have type 2 diabetes,[19] and older adults are more at risk for both acute and chronic complications of the disease. In addition to supporting weight loss, intermittent fasting can improve several other key risk factors for type 2 diabetes, including reducing insulin resistance and improving blood glucose control.[20,21]

Reduce inflammation 

Particularly for adults living with overweight or obesity, intermittent fasting has been shown to reduce inflammation and inflammatory diseases.[22] There’s also some evidence to suggest it may improve chronic pain from arthritis,[23] but alas, we need more research in this area, too. 

Improve memory retention 

Intermittent fasting may not give you the power to remember exactly where you put your keys (did you check the front door?), but it has also been shown to help with long-term memory retention and cognition.[24] 

Elevate mood

For some people, fasting may improve symptoms of stress and anxiety.[25] One study on healthy aging men found that intermittent fasting led to decreases in tension, anger, confusion, and total mood disturbance.[26]

Risks of intermittent fasting for seniors 

While fasting is safe for seniors in general, that doesn’t mean it comes without potential risks. Here’s a rundown of potential safety concerns. 

Nutrient deficiency 

The biggest challenge with managing intermittent fasting later in life is that you need to ensure you’re giving yourself the time and space to get all the extra nutrients you need each day. Otherwise, over time, deficiencies can lead to malnutrition, which could leave you more at risk for health conditions and even potentially increase your risk of early mortality.[27,28]

Dehydration 

When you’re eating less, you may be getting less water than usual since about 20% to 30% of our daily water intake comes from food.[29] Plus, older adults are more susceptible to dehydration to begin with.[30] If you don’t work extra hard to replenish that water supply, you can end up with everything from headaches and dizziness to cognitive impairments and a higher risk of illness.[31–34] 

Low blood sugar 

While decreasing blood sugar levels can generally improve metabolic health and weight management, low blood sugar can be dangerous for some people. Especially if you’re considering mixing intermittent fasting and diabetes, have concerns about fasting insulin levels, or have a condition that involves thyroid problems, you should consult your healthcare team.   

Fatigue and low energy

Although some research suggests intermittent fasting may help regulate your sleep cycle,[35] it may also decrease sleep quality or cause sleep disturbances.[36,37] Factor in the low blood sugar, and you might end up feeling groggy, foggy, or weak — at least until you adjust to your new eating routine. It’s also important to not ignore any usual and persisting changes in energy levels, so speak with your healthcare provider if something doesn’t feel right.

Most of these intermittent fasting side effects can be managed by avoiding common intermittent fasting mistakes, but because fasting affects everyone differently — and it’s not right or safe for everyone — you always want to work with your healthcare team to come up with a plan. 

Looking for ideas to discuss with them? Take our SIMPLE quiz to tell us about who you are and what you’re trying to achieve, and we can make some suggestions that might work for you. 

Best intermittent fasting schedules for seniors 

Let’s get real here: no matter what fasting-based diets for seniors we recommend, the most important thing to consider is you and your body. There’s no such thing as a universal “best” fasting plan, even within specific confines (age, sex, BMI, fasting goals, etc.). 

That’s one reason we always recommend speaking with your doctor rather than researching “intermittent fasting for seniors over 70” or “intermittent fasting after 50” and trying whatever plan comes up, Wheel of Fortune style. 

That said, there are three plans we recommend the most as being both safe and effective — and all of them fall into the category of time-restricted eating (TRE). 

TRE involves fasting for a certain number of hours (usually overnight) and then having the rest of the day to get all the nutrients you need. The most popular options are: 

• 12-hour intermittent fasting (a 12-hour fast followed by a 12-hour eating window)
• 14:10 intermittent fasting (a 14-hour fast followed by a 10-hour eating window)
• 16:8 intermittent fasting (a 16-hour fast followed by an 8-hour eating window)

At first glance, going 12+ hours without food may sound like a long time, but when you factor in the time you’ll be sleeping (hopefully ~8 hours!), it’s really just having dinner an hour or two earlier and breakfast an hour or two later. There’s even time for a snack still.

The fact that these TRE schedules are not only easier to manage but also involve less time when you won’t be eating as you normally would means they’re much easier to sustain and still allow you to meet your nutritional needs. 

Not coincidentally, these intermittent fasting schedules are the ones we recommend most for anyone who has a medical green light to try fasting. There are TRE schedules that involve longer fasting windows — as well as some other types of more on / off fasting approaches — but as a general rule at SIMPLE, we don’t recommend fasts that last 18+ hours.

SIMPLE’s tips on practicing intermittent fasting safely at a more mature age

Now that you’ve got the what and the why, what about the how? 

If your healthcare provider is on board with you trying a fasting-based eating routine, here’s how to set yourself up for a safe, successful experience. 

1. Have clearly defined goals. Whether you’re fasting for a singular goal like weight loss or overall health improvement, it’s a heck of a lot easier to develop an action plan — and identify any signs of “intermittent fasting not working” bumps in the road — if you know where you’re trying to go in the first place. 
2. Put yourself at the heart of the experience. Work with your healthcare team to figure out what intermittent fasting schedule(s) might align with your goals, needs, routine, and preferences. Factor in everything from your bedtime, exercise routine, and social commitments to what and when you need to take medication (especially if you’re on something that needs to be taken with food).  
3. Start slowly. Set your speedometer to The Tortoise and the Hare rather than The Fast and the Furious. Ease into fasting with shorter fasting windows and fasting only one or two days per week before ramping up. 
4. Pack in nutrients through health-promoting foods. Intermittent fasting doesn’t dictate what you eat, but prioritizing nutrient-dense foods like fruits, veggies, lean protein, whole grains, and healthy fats is like premium fuel — it provides extra support and leads to a smoother journey. Just make sure you’re building meals around foods you actually enjoy. Our guide on what to eat during intermittent fasting has lots of ideas. 
5. Become hyper aware of your hydration. Get the cutest, most outrageous water bottle possible. Download one of those apps where a plant reminds you to water yourself. Jazz up your H₂O with fruits, herbs, or spices. Whatever incentivizes you to stay hydrated, we’re all for it. You can also read our “what you can drink while fasting” guide for tips on what else you can drink during fasting periods.
6. Build in strength training. If it’s safe for you to do, combining intermittent fasting with resistance training can lead to better muscle retention.[38] There’s also a fair bit of research that suggests power training and strength training may support muscle power and endurance in older adults.[39,40] If you have any conditions that impact your mobility, speak with your healthcare provider before making any changes to your physical activity levels. 
7. Check in with yourself (and your doctor) regularly. Having regular “how’s this feeling” check-ins can help you stay on track with your goals and needs while also ensuring you catch any potential problems or safety issues early. 

Written by Aly Owen

Medically reviewed by Louise Bula, RD

Published on | Updated on March 28, 2024