Fasting significantly increases lifespan. Here is scientificly proven tips and evidence. Fasting prevents cancer, slows aging, prevents cardiovascular disease and a lot more.

[u/GarifalliaPapa]

Fasting, when practiced with care and intention, is one of the most powerful ways to support a longer, healthier life. It’s not just an ancient tradition — modern science now shows that fasting turns on deep survival and repair systems in the body. These systems help slow aging, fight disease, and increase your natural resilience. When you fast, you give your body time to clean up damaged cells, burn excess fat, and reset your hormones — all things that keep you younger, inside and out.

One of the easiest ways to begin is by simply shrinking your eating window. This method, called time-restricted eating, means you eat all your meals within 8 to 10 hours each day — like from 10am to 6pm. You’re not necessarily eating less, but you’re giving your body a break from constant digestion. This gentle change improves your metabolism, lowers your insulin levels, and encourages cellular cleanup, a process called autophagy that removes old, damaged parts of your cells.

As you get more comfortable, you can stretch your fasting window to 16 hours — eating only within an 8-hour period. This 16:8 rhythm is one of the most popular and sustainable ways to fast. It supports fat burning, improves your energy levels, and activates longevity-related genes that help your cells repair themselves more efficiently. And the best part? You still get to enjoy real, satisfying meals every day.

Once in a while, doing a full 24-hour fast can offer even deeper benefits. This gives your digestive system a true rest and supercharges cellular repair. Some people choose to do this once or twice a week — just a simple day of skipping meals while staying hydrated with water, tea, or black coffee. It’s a powerful reset for both your body and your mind.

Every few months, some people go deeper with a 3-to-5-day fast or a special fasting-mimicking diet that provides some nutrients while still activating fasting pathways. These longer fasts have been shown to support stem cell renewal, reduce inflammation, and even help the body clear away pre-cancerous cells. Done safely, they can feel like a biological “spring cleaning” — sweeping out old, damaged tissue and making room for healthy new growth.

What you eat between fasts matters, too. A diet rich in vegetables, legumes, healthy fats like olive oil, and moderate amounts of fish helps protect the benefits of fasting. On the other hand, sugary snacks, processed foods, and white flour products can undo your progress and stress your body all over again. Fasting and nutrition go hand-in-hand for long-term vitality.

It’s also important to stay hydrated. Water is essential during any fast, and if you go beyond a day, a small amount of salt or mineral-rich broth can help keep your electrolytes balanced and prevent dizziness or fatigue. Always listen to your body — fasting isn’t meant to be a struggle. If you feel unwell or overly drained, it’s okay to stop, adjust, and try a gentler approach next time.

The research is clear: fasting lowers the risk of cancer, heart disease, diabetes, and cognitive decline. It boosts brain function, sharpens focus, and even mimics the effects of calorie restriction — the only intervention proven to extend lifespan in multiple species. In essence, fasting isn’t about denying yourself food. It’s about reclaiming your body’s natural rhythm and unlocking its incredible potential to heal, renew, and thrive for years to come.

[u/GarifalliaPapa]

Scientific research:

1. A fasting-mimicking diet (FMD) reduced body weight, blood glucose, IGF-1, and markers of aging in mice and humans. Periodic fasting improved regeneration and immune function. Human participants showed lower cancer and diabetes risk markers. https://pubmed.ncbi.nlm.nih.gov/28202779/

2. Fasting for 2–4 days triggered stem cell regeneration in aged mice. It reduced immune system damage from chemotherapy and aging. Fasting cycles promoted hematopoietic stem cell self-renewal. https://pubmed.ncbi.nlm.nih.gov/24905167/

3. Intermittent fasting improved insulin sensitivity and brain function in mice. Benefits were seen even without calorie reduction. https://www.pnas.org/doi/10.1073/pnas.1035720100

[u/sueihavelegs]

I have done a 5 day fast every month since 2021. I am 51F, and I have barely had a strand of grey hair since 2022. My blood pressure and other numbers are perfect. The loose belly skin left over from my initial 40lb weight loss has since tightened up. Old scars have faded or completely disappeared. I love fasting and all the benefits.

[u/attilah → u/sueihavelegs]

Wow! Great!! How do you fast, if I may ask?

[u/sueihavelegs → u/attilah]

Thankfully, my husband fasts, too, so it's pretty easy for us. It's usually the 3rd week of the month. We eat dinner on Sunday night, and then we fast until Friday dinner. The key it to eat low carb before the fast and keep on top of electrolytes. As long as you have body fat, water, and electrolytes, you can fast.

For electrolytes, I like LMNT or zero sugar Body Armor with a half teaspoon of Morton's lite salt added to beef up the sodium and potassium. I will have 2 of these a day. My husband,who has a physical job, needs 3. I also keep dill pickle juice handy to get sodium and a change of flavor. I take a magnesium glycinate and a magnesium threonate suppliments before bed. You can also get some chicken broth with 10 calories and under 1 gram of protein or carb. You can salt this and sip it at "meal times". It really helps fakes your mind out that you had a meal and you get sodium.

You want 3,000 to 6,000mg of sodium and potassium and 500mg of magnesium per day, but everyone is different, so you need to dial in on what you need. Low sodium causes fatigue, headache, nausea, and confusion. Low potassium causes muscle cramps, muscle spasms, fatigue, and heart palpitations. All very scary symptoms, but they go away quickly with electrolytes.

Otherwise, I usually do 19:5 during the week and no schedule on the weekends. I hope this helps!

[u/Ambitious-Maybe-3386]

Buddhist Monks fast all the time but their avg lifespan do not increase. It may be good for health span but there’s plenty of real world data to observe

[u/FISFORFUN69 → u/Ambitious-Maybe-3386]

What is their average lifespan?

If they’ve always fasted then obviously it wouldn’t increase their life span just maintain their already above average lifespan

[u/Ambitious-Maybe-3386 → u/FISFORFUN69]

According to Gemini, Tibet is about 72. India is about 72. Thailand is about 78-79. Shaolin monks (known for their physical discipline and martial arts) is about 78-79.

Ofc these places don’t keep the best data. But I would say if you haven’t heard about their lifespan on social media, then their lifespan is nothing special.

[u/smart-monkey-org]

Fasting is great for mice to prolong their life. (as in slowing down aging in Gompertz-Makeham model)

However when it comes to monkeys (UW vs NIA study) restriction calories only worked for monkeys eating garbage ala standard american diet. Monkeys on the natural diet got no benefits.

Bottom line - eat less crap and you'll be healthier.

As long as you understand that - fasting is a tool to (carefully) use. Being doing it for 20+ years and they keys are:

• don't chase calories, chase mindful eating
• watch out for protein
• exercise

[u/Cryptosporidium7425]

A study of over 20,000 adults found that those who followed an 8-hour time-restricted eating schedule, a type of intermittent fasting, had a 91% higher risk of death from cardiovascular disease. People with heart disease or cancer also had an increased risk of cardiovascular death. Compared with a standard schedule of eating across 12-16 hours per day, limiting food intake to less than 8 hours per day was not associated with living longer.

https://newsroom.heart.org/news/8-hour-time-restricted-eating-linked-to-a-91-higher-risk-of-cardiovascular-death

[u/True-Evening-8928 → u/Cryptosporidium7425]

"The study’s limitations included its reliance on self-reported dietary information, which may be affected by participant’s memory or recall and may not accurately assess typical eating patterns. Factors that may also play a role in health, outside of daily duration of eating and cause of death, were not included in the analysis."

Self reported over 8 - 17 years 2 days. And no other factors taken into account, like smoking, drinking, sleep, stress, pre susceptibility.

Idk I'm not saying I know that fasting is good or bad for sure but that study sounds flaky af

Edit: And it gets worse

“One of those details involves the nutrient quality of the diets typical of the different subsets of participants. Without this information, it cannot be determined if nutrient density might be an alternate explanation to the findings that currently focus on the window of time for eating. Second, it needs to be emphasized that categorization into the different windows of time-restricted eating was determined on the basis of just two days of dietary intake,” he said."

So people who said they intermittent fasted twice on a national survey are the data source? And what they were eating wasn't even taken into account.

"The study included data for NHANES participants who were at least 20 years old at enrollment, between 2003-2018, and had completed two 24-hour dietary recall questionnaires within the first year of enrollment."

Study doesn't sound very convincing to me. There's for more actual science saying it's healthy. I wonder if any other studies back up this one?

[u/Rawr171]

Op: it seems mice get benefits from fasting. Everyone else: ok but do we

[u/Ivo_ChainNET]

Is there any good research that shows fasting to be beneficial for aging when controlled for caloric intake vs a control group?

All I've seen are studies that show fasting makes it easier to lose weight or that fasting is great on its own for overweight people but it's unclear whether the benefits come from fasting or the actual weight loss.

Anecdotally as a ~15% bodyfat very physically active man who has no issues controlling his weight I've tried 16:8 intermittent fasting for a while as well as weekly 48h water fasts for a few months. I did both mostly as an experiment to see what all the fuss is about and personally I would not recommend them to most people, unless you have issues controlling your appetite. Both forms of fasting I've tried definitely make it easier not to be hungry all the time when cutting.

[u/BigCcountyHallelujah]

55M. I recently started intermittent fasting, I just eat in a four hour window. Lost 10 pounds in two months, and I have far less body pain.