fasting for health and longevity

5 Steps to Fasting for Health and Longevity

The benefits of fasting for health and longevity are well-documented. In this post, I am going to show you exactly how you can start taking advantage of fasting to live younger longer in 5 simple steps.

Impact of Fasting on Health and Longevity

First, let’s look at how fasting works to increase your longevity.


There are more than 5,000 papers published each year on the topic of autophagy. It’s a fascinating and promising field! Fasting activates the process of autophagy. Autophagy is from the Greek language. Auto means “self”, phagein means “eat”. Basically, autophagy means your body is eating itself in the absence of food. Don’t worry! It’s a good thing because it is eating damaged and redundant cells. It contributes to inhibiting cancer cells and aging, eliminating pathogens and cleaning the insides of cells.

How Does Fasting Activate Autophagy?

When you are well-fed, all the cells in your body are in “growth” mode. Your cells are growing, dividing and synthesizing proteins. Your mTOR pathways ( mammalian target of rapamycin ) love having lots of protein and carbohydrates around. When your mTOR pathways are active they tell your body not to bother with autophagy.

Moreover, when you are fasting, your body perceives you are subject to environmental stress and protects you by changing the expression of your genes. Your body will turn on genes that are related to fat metabolism, stress resistance, and cell damage. Furthermore, some of your fat will be turned into ketone bodies, which lower inflammation and produce energy.

Fasting from anywhere between 12 and 24 hours activates autophagy. Every time you eat, your body produces insulin, which turns autophagy off.

Lastly, exercise can also induce autophagy.

How to Turn Autophaphy Off

In summary, here’s what reduces autophagy: glucose, insulin, and protein. To learn more about autophagy and the health benefits of fasting by the hour, read What Is Autophagy and How to Induce It.

Impact of Fasting on Health

A large body of research connects fasting with:

  • Improved blood sugar
  • Reduced inflammation
  • Weight loss
  • Improved brain function

Besides stimulating autophagy, fasting stimulates growth hormone production. So, your body gets rid of the old stuff and replace it with new stuff.

Human Growth Hormone

Human growth hormone (HGH) is essential to promote growth during childhood and to maintain tissues and organs afterward. It is produced by the pituitary gland. However, during middle age, the gland slowly reduces its human growth hormone production.

Fortunately, fasting helps increase growth hormone. For example, a 5-day fast will increase HGH by 300%! A 2-day fast causes a 5-fold increase in HGH.

Calorie Restriction for Health and Longevity

Did you know that studies show that a 20-50% calorie reduction in mice can increase their lifespan by up to 50%? Moreover, it delays the onset of chronic diseases such as:

  • Obesity
  • Type 2 diabetes
  • Cancer
  • Neurodegeneration
  • Multiple autoimmune diseases

Studies investigating humans show similar results.

Effects of calorie restriction

However, it is important to note that a calorie restriction of 25% or less is optimal to avoid negative consequences like emotional distress, apathy, confusion, depression, eating disorders, and loss of sex drive. Studies have shown that mild calorie restriction (25% or less) for 2 years had no negative effects on the quality of life.

Fasting Vs. Calorie Restriction for Health and Longevity

Fasting diets or “intermittent fasting” can be used to obtain the same results without the difficult mental hurdle associated with constant calorie restriction. Researchers think that the ketones produce during fasting are a more efficient source of energy. They may protect “against aging-related decline in the central nervous system that might cause dementia and other disorders“.

Unfortunately, most of the data we have on the topic of fasting and calorie restriction is from animal studies. However, many small-scale studies on humans seem to show that intermittent fasting without calorie restriction can offer the same benefits on health and longevity.

It’s up to you to decide which approach you can maintain long term. For most of us, intermittent fasting is more doable than continuous calorie restriction.

The Longevity Diet

How can we talk about fasting and longevity without mentioning Dr. Valter Longo, creator of the fasting mimicking diet? Dr. Valter Longo, author of The Longevity Diet book has been researching, fasting, and longevity for over 30 years. He has identified a few key points that seem to promote longevity when it comes to your diet:

  • Follow a pescatarian diet. Dr. Valter Longo recommends a diet that is mostly plant-based but includes fish 2 or 3 times a week. He also recommends avoiding fish that are high in mercury like tuna, swordfish, mackerel, and halibut. For those who are over 65, he recommends the addition of other animal-based foods like eggs, certain cheeses (feta or pecorino), and goat’s milk yogurt.
  • Consume low amounts of protein. All you need is 0.31 to 0.36 grams of protein per day. Again, after age 65, you can increase your protein intake by 10 to 20 percent.
  • Minimize bad fats and sugars. Choose good fats and complex carbs instead. Your fats should come from olive oil, salmon, almonds, and walnuts. For carbs, consume whole bread, legumes, and vegetables. Limit pasta, rice, bread, fruit and fruit juices, which are easily converted into sugars.
  • Supplement wisely. Choose nutrient-dense foods, but as an insurance supplement with a quality multivitamin, minerals, and omega-3.
  • Eat a variety of foods from your ancestry. You need a wide variety of foods to get all the required nutrients but it is best to choose from foods that were common on your parents’, grandparents’, and great-grand-parents’ table. For example, lactose intolerance is relatively rare in northern European countries, but it is common in southern European and Asian countries. Milk was not historically part of the traditional diet of these populations.
  • Eat twice a day plus a snack. Three meals a day is too much for the average person. A surplus of only 30 calories a day is enough for a 3-pound weight gain each year.
  • Observe time-restricted eating. Consume all your meals within eleven or twelve hours each day.
  • Practice periodic prolonged fasting. People under the age of 65 who are neither frail nor malnourished and are free of major diseases should do the fasting mimicking diet 3-4 times a year.
  • Maintain a healthy weight and abdominal circumference. Hight waist circumference and abdominal fat are associated with increased diabetes, hypertension, high cholesterol, and heart disease. Calculate your waist to height ratio.

The above dietary recommendations are rooted in the Five Pillars of Longevity that Dr. Valter Longo explains in his book, The Longevity Diet.

How to Use Fasting for Health and Longevity in 5 Steps

If like me, you decide to use fasting to improve your health and longevity, you can follow the following 5 simple steps.

1. Set a Goal

Make sure you set a measurable goal. There is nothing “superficial” about a weight loss goal. Lowering your BMI (Body Mass Index) will improve your health in many ways. For example, a lower BMI is associated with a lower diabetes risk even among people who are not overweight. Other health conditions are linked with excess weight, including:

  • arthritis
  • liver disease
  • cancer
  • high blood pressure
  • high cholesterol
  • sleep apnea

If you do not wish to track your weight or your BMI and suffer from a chronic condition, you may opt to set a goal to improve your numbers on your blood panel. Whatever you choose, set a goal that you can measure. This will help keep you motivated and decide if you are on track.

2. Pick Your Fasting Method

For health and longevity purposes, autophagy is very important. Maximum autophagy happens around the 3-day mark. However, decreasing your insulin levels will impact your general health in many ways and that happens at the 12-hour mark. To learn more about how long to fast depending on your health goals, read How Long Should You Fast for Maximum Benefits.

If you are a beginner who would like to benefit from prolonged fasting while eating, you need to consider the fasting mimicking diet. I created a plan that is super easy and straightforward. Read The Easiest and Simplest Meal Plan Ever to DIY the Fasting Mimicking Diet.

fasting personality quiz

3. Decide What to Eat

Whether you go for a fruit fast, a water fast, a 10-day challenge diet, intermittent fasting or the fasting mimicking diet, practicing a fast and filling up on junk food the rest of the time will not serve you in the long run. Choose your foods wisely. Favor simple meals made with nutrient-dense whole foods.

You may decide to go on a clean ketogenic diet (read the difference between clean and dirty keto), Paleo, pegan, or vegan. Whatever it is, make sure you don’t fill up on premade foods filled with vegetable oils, sugar, and preservatives.

Check the section about Dr. Valter Longo and his longevity diet for more inspiration.

Read 15 Best Foods to Break a Fast for more inspiration on what to eat after fasting.

nutrient dense foods chart

4. Track Your Progress

Tracking your progress will help you stay motivated. Make sure you stick with your fasting methods for at least a month. Then, track your measurable goal. Whether it is weight loss, inches lost, or blood panel results, you need to give it enough time before deciding that it’s not for you. However, listen to your body. If you feel miserable and deprived, it’s not sustainable. Whatever method you choose has to be something you will be doing for the rest of your life pretty much.

If your fasting method is too hard and miserable, try a different one. Play around until you adjust. You may find that a method that used to be incredibly difficult becomes easy. The good thing about intermittent fasting is that there are a lot of ways to practice it. You can decrease your fasting window or pick a method that is not daily like the Crescendo Method, Alternate-Day Fasting, or the 5:2 Method.

5. Troubleshoot

Troubleshooting is an important step. If fasting has not been getting you the results you want, you may experiment further. Women’s hormones are especially sensitive to fasting. Read How Fasting Affects Women’s Hormones to learn more.

I mentioned already that you should stick to your method for at least a month before you start troubleshooting unless you feel miserable. Even if you pick something like the fasting mimicking diet, which is only 5-day of the month. What I found the first time I did the fasting mimicking diet is that although I gained the weight I had lost back when I started eating normally again after the 5-day fast, I did not gain the belly back and my weight started going down again during the rest of the month after I had gained it back.

Read my Fasting Mimicking Diet Results if you are curious.

Fasting for Health and Longevity Video

In Summary

Fasting may be superior to continuous calorie restriction for health and longevity because it is more sustainable long term for the average person. Instead of becoming “hangrier and hangrier”, your body starts using ketones for fuel and you naturally start feeling satisfied with less food and fewer meals. Just keep in mind that becoming fat-adapted may take a while. Don’t give up and keep experimenting until you find the right fasting method for you. To help you get started, take my quiz What is Your Fasting Personality? You will receive 3 free quickstart guides that you can use as a foundation.

fasting for health and longevity