Autophagy During Intermittent Fasting: What You Must Know Before You Start Fasting

Autophagy During Intermittent Fasting: What You Must Know Before You Start Fasting
Cordelia Tan

Cordelia Tan | Author

Cordelia Tan, is a passionate advocate for women's health and well-being. Known as Fasty's number one fan, she expertly blends Eastern and Western health practices, offering a holistic approach to diet and wellness. Her work focuses on empowering women with knowledge and practical strategies for a healthier life.

Autophagy, a cellular self-cleaning mechanism, is currently being explored as a possible new modality for treating diverse pathologies, including neurodegeneration and heart disease. These autophagic processes can be triggered by putting cells under stress, like with intermittent fasting.

While the relation between fasting and autophagy is clear, the missing piece to the puzzle is, how long do you have to fast for autophagy to kick in?

What Causes Autophagy?

Autophagy is a cellular mechanism that helps maintain cellular health. Cells recycle or degrade damaged or unnecessary components such as proteins, organelles, and pathogens. 

This natural process helps cells:

  • regulate cellular homeostasis,

  • adapt to stress conditions, and

  • promote cell longevity and resilience.

How Is Autophagy Induced in Our Body?

Autophagy begins as a response to cellular signals when they are under stress due to nutrient deprivation, the presence of damaged cellular parts, or oxidative stress. The signals activate specific pathways that incite the formation of autophagosomes, structures involved in cellular recycling, thus initiating the process of autophagy.

When Does Autophagy Start While Fasting?

Intermittent fasting can prompt autophagy by activating a survival response in the body. When the body has depleted its nutrient storage due to the lack of food intake during fasting, cells recondition themselves to adapt to the shortage of nutrients. The body then outsources energy from fat reserves triggering autophagy.

A short-term fasting experiment looked into the autophagic response of fasting in animals. This study demonstrated autophagy reactions in murine hepatic tissues and neuronal cells. The number of autophagosomes in the liver increased during the first 24 hours of fasting and was highest after 48 hours. 

To date, there haven’t been sufficient scientific studies conducted on the induction of autophagy in humans. Cellular response and timing of autophagy activation will differ from person to person. For a better understanding of when autophagy may occur, track your fasting and eating hours using the Fastic app to monitor your progress smoothly.

Additional Factors that Stimulate Autophagy

Fasting is not the only factor that starts autophagy, other factors can initiate it.

Calorie Restriction

Although calorie restriction and intermittent fasting are different dietary approaches, both require the reduction of calorie intake to some extent. Calorie restriction encourages the body to repurpose cell components due to the low nutrient intake required.


Exercising increases energy demand, which leads to nutrient depletion and cellular stress. Studies have shown that exercise induces autophagy in multiple organs involved in metabolic regulation, such as muscle, liver, and pancreas.

Nutrient Availability

Investigations on the effects of autophagic responses in fasting concluded that the lack of essential nutrients like glucose or amino acids can support energy depletion, prompting autophagy.

What Foods Induce Autophagy?

Caloric restriction and exercise are not the only ways to trigger autophagy, certain foods promote cell renewal too. Research has found that foods containing polyphenols can stimulate pathways that lead to autophagy. There is no definite autophagy diet plan, however, incorporating foods containing polyphenols in your meals can help promote cell recycling processes. 

The following foods are known to contain polyphenols:

  • Fruits: berries, apples, grape skin

  • Vegetables: spinach, kale, broccoli

  • Nuts and seeds: almonds, walnuts, peanuts

  • Beverages: Green and black tea, coffee

  • Herbs and spices: cinnamon, cloves, oregano

  • Legumes: soybeans, chickpeas, lentils

  • Whole grains: whole wheat, oats

It is important to note that when fasting, beverages like black coffee and herbal teas are allowed. Drinking these beverages won’t interfere with the body’s fasting state, can help ease hunger cues, and is a healthy source of polyphenols during eating windows.

when does autophagy starts

Health Advantages of Autophagy

Anti-bacterial and Viral Role

Autophagy plays an important role against infectious diseases, directly and indirectly, by simultaneously degrading pathogens and activating the host’s immune system. Furthermore, autophagy also aids in cellular defense against viruses. Autophagic processes help clear viral pathogens during infection, regulate immune responses, and prevent harmful inflammation.

Anti-aging Effects

Inefficiencies in autophagy mechanisms may promote accelerated skin aging. Research suggests that autophagy in skin cells may bring advancements in preserving skin function in aging individuals, hence the popularity of fasting among women over 50.

An early time-restricted feeding study demonstrated that autophagy can increase lifespan and have anti-aging effects in humans. Findings indicate that autophagy aids in maintaining organelle homeostasis and can help prevent the development of age-associated processes

Promotes Weight Loss

During fasting, due to the limited or null intake of nutrients, the body needs to resort to other sources of energy. When glucose levels drop due to fasting, and the body exhausts its glucose storage, it then resorts to the breakdown of stored fat for energy. The process of breaking down fat to make ketones is known as ketosis. Ketosis and autophagy, among other mechanisms, are triggered during fasting and can contribute to weight loss.

How to Do Fasting to Promote Autophagy?

Various fasting methods can be practiced to encourage autophagy in the body. Intermittent fasting regimens vary in intensity. Depending on your health goals and commitment level, the fasting plan you choose will vary in duration and severity. The Fastic quiz can help you by tailoring your preferred fasting schedule or giving you a preset one. 

Fasting plans that may incite autophagy are:

  • Time-restricted eating

  • 5:2 method

  • Alternate-day fasting

  • Extended fasting

No matter which fasting method you choose, when autophagy starts will depend on your body. Remember, the previously mentioned research finding of 24 hours as a threshold to initiate autophagy is not definitive and may differ from person to person.

Applications of Autophagy in Disease Treatment

Autophagy has demonstrated positive results in treating various diseases through research and clinical trials. These ongoing investigations have shed light on the quest for new treatment possibilities in the medical field. 

The following is a list of the applications autophagy has in disease treatment.

Is Autophagy Good or Bad for Your Health?

Without autophagy, cells would not be able to remove dysfunctional or useless parts, which in turn would end up in an accumulation of damaged material. This accumulation will interfere with correct cellular functioning, weaken tissue health, and increase disease vulnerability, such as neurodegenerative disorders and cancer. Additional benefits of autophagy include improvement in 24-hour fast glucose levels and altering lipid metabolism.

On the other hand, just like autophagy can have advantages, it can also have disadvantages. Studies indicate that autophagy may protect tumors from immune attacks. Moreover, studies show that when a protein called RAS is activated in tumor cells, it causes them to depend more on autophagy. Autophagy maintains a cell’s mitochondria (energy producers), especially when there is nutrient insufficiency, which encourages tumor growth.

It is important to note that fasting is not adequate for everyone. Before starting a fasting plan it is advised you consult with your healthcare professional, particularly if you suffer from a medical condition.  

Achieve Maximum Cellular Health

Fasting can promote cellular renewal processes in the body, encouraging optimal cellular health. With vast research and scientific trials exploring the possibilities of using autophagy as a possibility to treat diseases, using it to enhance your health holds significant promise.

Explore Fastic’s fasting plans to leverage fasting for improved health and reach maximum cellular health. 

Disclaimer: It is advised to speak with a health professional before beginning intermittent fasting or a diet program. There may be side effects for people with certain medical conditions.

With Fastic, millions of people have achieved their desired weight, overcome disease and regained their quality of life.

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