What Are The Effects Of Intermittent Fasting?


Intermittent fasting has a wide range of health benefits that researchers are looking more closely into. With an intermittent fast, the body is able to use up its energy stores while a person takes in very little to no food. It’s done in a way that a person is still providing their body with needed nutrients, but allowing the body to use up its energy stores.

When a person uses up their energy stores, they are entering autophagy, which literally means to “self-eat.” While it may sound scary, it is a necessary function of the body for cell renewal. In autophagy, the body is literally ridding itself of old, damaged cells in order to make way for new, healthier cells. This process not only helps the body defend against diseases, it also helps the body to stay young.

Spermidine helps the body through the autophagy process because it is a polyamine, which plays an essential role in cell growth. Read on as the team at spermidineLIFE® takes a closer look at healthy aging and intermittent fasting.

How Can I Reverse Aging Naturally?

Taking care of yourself is the best thing you can do to age gracefully while maintaining youth both internally and externally. Diet plays a big part in healthy aging and one of the most profound ways to do so is following the Longevity Diet, which naturally tends to promote autophagy through its eating style. This diet follows these simple rules:

  • Eat a mostly vegan diet
  • Fish can be consumed 2-3 times a week
  • Keep protein intake low
  • Minimize saturated fats from animal and vegetable sources
  • Minimize sugar
  • Maximize good fats like olive oil
  • Maximize complex carbs like whole grains
  • Eat a diet high in vitamins and minerals, supplementing with a multivitamin every three days
  • Eat 2-3 meals a day depending on your weight
  • Eat all meals within a 12 hour period
  • Avoid eating 3-4 hours before bedtime

The diet is healthy and sounds easy to follow, but may require a major shift in Western thinking where oftentimes meat is put first on the plate and vegetables are just sides. But lower protein and higher vitamins and minerals requires a shift in eating style.

Can You Reverse Aging Skin With Diet?

Providing the body with whole foods and the nutrients it needs while also allowing it the rest it needs to maximize the calories consumed, is naturally anti-aging. This is for a couple of reasons. First, the body needs vitamins and minerals to function properly

Second, limiting the amount of time food is consumed during the day will allow the body to get rid of old, damaged cells in order for new ones to be formed.

tomatoes, bananas, cucumbers and other vegetables that are perfect foods to break a fasting

Anti-Aging Foods

We know vegetables and fruits provide the body with nutrition, but there are some that pack a higher nutritional punch such as:


This acts as an internal skin antiseptic increasing circulation and delivery of minerals to the cells. It is also high in vitamins A and C. Plus the antioxidants may neutralize harmful free radicals.

Red Bell Pepper

These are loaded with antioxidants like carotenoids and vitamin C, which helps collagen production.


Papayas are loaded with antioxidants, vitamins and minerals that help fight free-radical damage. They also have an enzyme called papain, which is one of nature’s best anti-inflammatory agents and used in many skin-care exfoliating products.


Rich in vitamins like A and C, they also contain an antioxidant that may protect skin from damage.


Loaded with vitamins, antioxidants as well as fiber, this vegetable is an anti-aging powerhouse.


This contains antioxidants to help oxygenate the entire body.


Most nuts are high in vitamin E which protects skin and repairs tissue.


High in fatty acids that promote smooth skin.

Sweet Potatoes

The orange color is beta-carotene, which converts to vitamin A, which helps promote cell turnover and skin elasticity.

Pomegranate Seeds

High in vitamin C and antioxidants, they reduce levels of inflammation in our system.

Benefits Of Autophagy

Autophagy is the body’s way of self-preservation to rid bad and damaged cells on the path to cellular repair and optimal function. One of the main benefits of autophagy is that it's a natural anti-aging process.

Our cells are constantly damaged through natural processes that come with being a human being such as eating and digesting. Autophagy is the body’s natural process to clean out damaged cells and make way for newer, healthier ones.

Diet is one way to introduce autophagy through intermittent fasting. And autophagy supplements are another way including spermidine.

How To Introduce Autophagy

Diet is one way to initiate the autophagy process. This can be done through intermittent fasting and ketogenic diets. Fasting allows the body to use its energy stores. Remember autophagy means to self (auto) eat (phagy).

Ketogenic diets do that as well because they are high in fats and low in carbs which gives the body time to break down the fat the body has stored for fuel instead of glucose taken in through carbohydrates.

Spermidine supplements aid the body in the autophagy process because they assist with cell renewal.

How Long Do You Have To Fast For Autophagy?

Intermittent fasting benefits the body because it gives the body time to repair damage. When we are constantly consuming calories, cells are growing and dividing, not getting rid of the damaged ones. 

The benefits of autophagy occurs within this timeframe:

12 Hours

The body enters the metabolic state of ketosis where it breaks down and burns fat.

18 Hours

The body switches to fat-burning mode, generating significant ketones. The body begins to reduce inflammation and repair damaged DNA.

24 Hours

The body enters autophagy where cells are increasingly recycling old components and misfolded proteins linked to many diseases such as Alzheimer’s. 

48 Hours

With little to very few calories, the growth hormone is five times higher than when the fast started. This hormone preserves lean muscle mass and reduces fat tissue accumulation.

54 Hours

Insulin drops to the lowest point since the fast started. This can reduce inflammation and makes a person more insulin-sensitive, which is a good thing if a person is at risk of developing diabetes.

72 Hours

The body is breaking down old immune cells and creating new ones.

What Is Allowed During Intermittent Fasting?

Intermittent fasting is a pattern where people go between eating and not eating. There are many different styles of intermittent fasting including:

16/8 Method

Fast for 16 hours a day and only consume food within an 8-hour window.


A 24-hour fast where once or twice a week you don’t eat anything from dinner one day to dinner the next day.

5:2 Diet

Eat only 500-600 calories for two days during the week.

Does Your Body Go Into Ketosis When Intermittent Fasting? 

It is possible to enter ketosis during intermittent fasting. Some people can go into ketosis between meals such as between breakfast and dinner. It is possible for a person to enter ketosis in a rather short amount of time.

Ketogenic Diet And Skin Aging

Keto may improve skin with some people touting a clearer, brighter complexion. Whereas others reported an itchy red rash on their torso, which happens in the early stages of ketosis.

Everyone’s skin is different, but the omega-3 fatty acids the ketogenic diet is known for are beneficial for healthy skin. Keto is a diet that cleans out the inside of the body. And cleaning out the bad cells for new cells are beneficial to the skin.

How Do I Get In Ketosis Intermittent Fasting? 

The body can get into ketosis in as little as 12 hours, but can also take up to 2 days or more if a person’s glycogen reserves are full. One way to know if the body is in ketosis is through a blood test where blood ketone levels > 0.5 millimolar/L.

People can stay in ketosis for as long as they are able to through intermittent fasting and/or following a ketogenic diet. People entering ketosis may experience some unpleasant side effects that should dissipate once full ketosis is entered including:

  • Fatigue
  • Irritability
  • Headache
  • Lack of motivation
  • Stomach issues like diarrhea or constipation
  • Sugar cravings

The body is going through a change so it will take time to adapt.

How Long Does It Take For Your Body To Go Into Ketosis Intermittent Fasting?

Another way to enter ketosis is through the One Meal A Day (OMAD) plan. It is a more controlled version of fasting and the one meal consumed each day is keto-friendly (high fat, low carb).

The body can enter ketosis quickly, but it may not be sustainable for the long-term since it may be difficult for some to follow.

Supplements To Support Intermittent Fasting And Help Anti-Aging

Spermidine can support cell renewal through the autophagy process by replenishing the body’s polyamine levels that help with cell growth and renewal. New, healthy cells protect the body against the effects of aging. 

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  • Don Moxley - Director of Applied Science

    Don Moxley is the Director of Applied Science at Longevity Labs. Moxley draws upon his career as an athlete, a sports scientist, and an instructor to lead and educate on the science of autophagy and longevity.