Print Friendly, PDF & Email

Dieting can be a difficult and frustrating way to lose weight. Intermittent fasting is a simple and effective strategy for getting lean while maintaining muscle mass.

Intermittent Fasting


Intermittent fasting is a technique primarily used for losing weight that comes with many health benefits. It involves changing your eating pattern without having to change your diet or exercise level.

There are many different ways to fast. Common practices include:

  • Alternate day eating – one day on and one day off
  • Time restricted eating – typically involves skipping breakfast (but I don’t approve)
  • 5:2 fasting protocol – restrict calories to 500-700 per day for two days a week

Intermittent fasting is effective because it allows the body to enter its highest fat-burning state, which occurs about 8-12 hours after eating a meal. This helps eliminate body fat without sacrificing muscle mass. A typical eating schedule does not normally allow the body to reach this point.

1) Intermittent Fasting Helps You Lose Weight

Studies have found that the 5:2 fasting protocol has been the most effective for losing weight (R).

A 2013 study found that people who steadily reduced their daily calorie intake became more insulin sensitive and lost more weight compared to people who followed a regular eating pattern (R).

Intermittent fasting has been effective in preventing obesity (R).

Efficiency of metabolism is improved as a result of intermittent fasting (R).

2) Intermittent Fasting Can Prolong Your Life

Intermittent fasting can increase a person’s lifespan by up to 30% according to some researchers (if animal studies are an indicator) (R).

Intermittent fasting boosts the body’s stress resistance, which increases longevity in humans (R).

It helps protect and treat the body from disease, which can delay aging (R).

Intermittent fasting can prolong the health-span of the nervous system by impacting biological pathways that regulate the lifespan (R).

3) Intermittent Fasting May Reduce the Likelihood of You Getting Sick

In a study done on mice that were infected with salmonella, intermittent fasting lowered intestinal and systemic bacteria by boosting their intestinal immune system (R).

4) Intermittent Fasting Promotes Cardiovascular Health

Intermittent fasting:

  • Decreases cardiovascular disease risk (R).
  • Increases HDL cholesterol and lowers triglyceride levels and LDL cholesterol (R).
  • Decreases resting heart rate and blood pressure (R).
  • Improves circulation of triglycerides and cholesterol (R).
  • Increases resistance to ischemic injuries (R).
  • Reduces the risk of coronary heart disease (R).

5) Intermittent Fasting Decreases Cancer Risk

Intermittent fasting lowers blood glucose and IGF-1 levels, which reduces the risk of cancer (R).

Studies have found that reducing energy intake and fasting for longer intervals during the night can reduce the risk of breast cancer (R).

6) Intermittent Fasting Can Forestall Cognitive Decline

Intermittent fasting protects neurons from genetic and environmental stress factors during aging (R).

Intermittent fasting increases insulin sensitivity, which benefits neurons that stimulate the production of enzymes that help cells cope with stress and fight against disease (R).

Fasting can reduce issues with brain function and neurodegenerative disorders caused by inflammation (R).

7) Intermittent Fasting Can Prevent Chronic Degenerative Diseases

Fasting reduces inflammation and boosts cellular protection (R).

Intermittent fasting helps protect against obesity, diabetes, rheumatoid arthritis, hypertension, and asthma in humans (R).

Intermittent fasting protects against damage caused by an ischemic stroke (R).

Calorie restriction increase sirtuins and AMPK signaling, which help the body maintain internal stability (R).

8) Intermittent Fasting Heals Your Gut

Motilin and Ghrelin, which regulate the digestive tract, are released during fasting (R).

Ghrelin readies the body for the incoming nutrients by stimulating gastrointestinal motility and gastric acid secretions (R).

Studies show that there may be a therapeutic use for ghrelin in gastrointestinal inflammatory diseases like colitis and ischemia (R).

Fasting therapy has improved abdominal pain, diarrhea, nausea, and anxiety in patients with irritable bowel syndrome (R).

9) Intermittent Fasting Boosts Mood and Motivation

Studies show that fasting and calorie restriction improves anger, tension, confusion, and overall mood in aging males (R).

High levels of ghrelin are associated with anti-depressant effects (R).

10) Intermittent Fasting Is A Cognitive Enhancer

IF affect energy and oxygen radical metabolism, and cellular stress response systems, in ways that protect neurons against genetic and environmental factors to which they would otherwise succumb during aging (R).

Fasting increases the presence of drebrin, a protein that regulates neuronal development (R).

The loss of drebrin results in cognitive impairment that causes neurological disorders (R).

Intermittent fasting is associated with growth of the hippocampus, which is responsible for emotion and memory (R).

11) Fasting Reduces Inflammation

Fasting produces ghrelin in the body, which suppresses inflammation (R).

Intermittent fasting reduces pro-inflammatory cytokines and immune cells in the body (R).

Fasting for long intervals at night can reduce systemic inflammation (R).

Intermittent fasting reduces the risk for degenerative diseases connected to inflammatory response in the central nervous system (R).

12) Increased Ghrelin Levels May Slow the Onset of Parkinson’s Disease

Ghrelin increases the concentration of dopamine in an area of the brain where the decline of dopamine cells leads to Parkinson’s Disease (R).

13) Intermittent Fasting Improves Learning and Memory

A study demonstrated that mice on intermittent fasting had better learning and memory than mice with a regular eating schedule (R).

Studies suggest that learning may be best when the stomach is empty during the day because ghrelin levels are high (R).

14) Intermittent Fasting Protects Against Diabetes Risk

Intermittent fasting is associated with a reduced risk of diabetes (R).

15) Fasting Protects Against Autoimmune Disease

Fasting every three days has been effective in reducing autoimmunity and promoting regeneration (R).

Studies have shown that periods of fasting reversed symptoms of multiple sclerosis in animals (R).

Fasting prevents and improves systemic lupus erythematosus (R).

16) Intermittent Fasting Improves Sleep

Periods of fasting can lead to decreases in arousal during sleep (R).

Intermittent fasting has proven to benefit daytime performance and quality of sleep in non-obese individuals (R).

17) Intermittent Fasting Helps Protect Against Infections

Periods of food deprivation increases resistance to salmonella typhimurium infection because the body produces more IgA, which is critical in immune function (R).

Intermittent fasting promotes responses in the brain that suppress inflammation and maintain cognitive function during systemic bacterial infection (R).

Neutrophils have a preference to engulf refined carbohydrate (glucose, fructose, sucrose, honey and orange juice) over bacteria (R).

The neutrophil phagocytic capacity to engulf bacteria is affected when simple sugars are digested. And fasting strengthens the neutrophils phagocytic capacity to engulf bacteria (R).

However, the digestion of normal starches has no effect. The researchers concluded that the scientific data found that the function, and not the number of phagocytes in engulfing bacteria was altered by the ingestion of sugars (R).

Even among sugars, neutrophils can again be picky and engulf preferred sugars (R, R2, R3).

18) Intermittent Fasting Allows You to Maintain Your Performance

Intermittent fasting has no effect on daily functioning and sports performance (R).

Intermittent fasting does not promote drowsiness or lack of vigilance (R).

This method of fasting preserves lean body mass (R).

The cellular effects of intermittent fasting are similar to the effects of physical exercise (R).

19) Intermittent Fasting Heals Your Skin

There is evidence that intermittent fasting may aid in skin wound healing (R).

Fasting has been effective in alleviating contact dermatitis and chronic urticaria (R).

The effects of intermittent fasting can assist with fighting acne (R).

20) Intermittent Fasting Helps Ease Chronic Pain

Intermittent fasting enhances neuroplasticity and learning in adults, which can aid in healing chronic pain (R).

My Recommendation On How To Do It (The Diet / Schedule)

For most readers of this blog, I will recommend doing a restricted eating window from 8am to 6PM – that means eating only from 8am to 6PM.

You can also do the 5:2 protocol while you’re at it, which means to do a 24 hour fast two days a week (separated by at least one day).

Eat your normal diet five days a week. Pick any two days of the week to restrict your intake of food to fewer than 700 calories.

You will get the best results if your “normal diet” is a healthful one, but you do not need to try to restrict calories on your non-fast days.

For people with inflammatory issues, I’d recommend the Lectin Avoidance Diet.

Potential Negatives

In a study involving mice who didn’t have LDL receptors, intermittent fasting increased insulin resistance, and total and LDL cholesterol compared to mice following a normal eating pattern (R).

This means that if your LDL receptors are problematic, you should be wary of intermittent fasting.

You can check your LDL receptors by getting your genetics (by 23andme) sequenced and upload it to SelfDecode.

Who Shouldn’t Try Intermittent Fasting

  • People with circadian rhythm issues
  • People who have neuroendocrine issues and glutamate excitotoxicity, although following my approach will minimize the downside
  • People who get hypoglycemic
  • People who are severely underweight
  • People who are trying to have a child
  • People with hypercholesterolemia.

Health Tools I Wish I Had When I Was Sick

At SelfHacked, it’s our goal to offer our readers all the tools possible to get optimally healthy. When I was struggling with chronic health issues I felt stuck because I didn’t have any tools to help me get better. I had to spend literally thousands of hours trying to read through studies on pubmed to figure out how the body worked and how to fix it.

That’s why I decided to create tools that will help others cut down the guesswork:

  • Lab Test Analyzer – a software tool that will analyze your labs and tell you what the optimal values are for each marker — as well as provide you with actionable tips and personalized health and lifestyle recommendations to help you get there.
  • SelfDecode – a software tool that will help you analyze your genetic data from companies such as 23andme and ancestry. You will learn how your health is being impacted by your genes, and how to use this knowledge to your advantage.
  • SelfHacked Secrets – an ebook where we examine and explain the biggest overlooked environmental factors that cause disease. This ebook is a great place to start your journey if you want to learn the essential steps to optimizing your health.
  • SelfHacked Elimination Diet course – a video course that will help you figure out which diet works best for you
  • Selfhacked Inflammation course – a video course on inflammation and how to bring it down
  • Biohacking insomnia – an ebook on how to get great sleep
  • Lectin Avoidance Cookbook – an e-cookbook for people with food sensitivities
  • BrainGauge – a device that detects subtle brain changes and allows you to test what’s working for you
  • SelfHacked VIP – an area where you can ask me (Joe) questions about health topics

FDA Compliance

The information on this website has not been evaluated by the Food & Drug Administration or any other medical body. We do not aim to diagnose, treat, cure or prevent any illness or disease. Information is shared for educational purposes only. You must consult your doctor before acting on any content on this website, especially if you are pregnant, nursing, taking medication, or have a medical condition.


1 Star2 Stars3 Stars4 Stars5 Stars (23 votes, average: 4.48 out of 5)

Why did you dislike this article?



  • alexandre

    hello.. I do intermittent fasting for almost 1 year. I lose like 10 kg . I use to do my exercises fasting in the morning . then I tried the gladiator diet , it’s like eating 1 huge meal on a window of 3 hours.. then I fast until the 24 hs. I think i was addicted in stay without eating, like a compulsive behavior. more I been without good, more I wanna be without food. then , like 2 months ago, I start to feel numbness on my feet and tingling on hands .. I feel very worry about.. go to a neurologist and get some tests.. I discovered a hereditary neurologic disease named by charcot Marie tooth. it’s a rare disease that affects 1 in 2500 people. I stop completely the if and start to blame myself.. I think if trigger that disease on me. I looked for some research about that, but I didn’t found anything specific related that link this disease and if, just one article that mention the relation between if and hereditary disease… so I wanna warning you guys about the unknown dangerous of IF. .. if I can back in time, I’ll never do IF again.. be careful mates..

  • larry boyle


  • John

    Well written and thorough article. I try and do 1 intermittent fast once per week. I aim for 18-20 hours. I stick with lots of water and a couple cups of black coffee to get me through it.

  • Roderick Beck

    Intermittent fasting does not work by directly reducing toxins. It encourages autophagy, which is the body’s garbage collection and recycling mechanism. Aging results in cellular garbage build up as autophagy declines.

  • Ethan

    I do 16/8 or 18/6. It does work! I combine it with no sugar and very little carbs. 25% protein, and I eat healthy fats as well. Forget your weight benefits… go take your blood test after three months of your 16/8. You’ll see… perfect. 16/8 allows your body to get rid of toxins, digest, relax… not eat… just chill.

  • Alejandra Viviescas

    I am very curious as to why you do not aprove on skiping breakfast. I am doing 16/8 intermittent fasting everyday and I am very pleased with the way I feel, I am skiping breakfast though, so I really want to know why you don’t think it’s the best approach.

  • Ethan

    It works!!! I literally eat anything. A mix of healthy KETO type choices (organic meats, kale, no carbs) to… definite obvious and hidden junky ones (rice, tofu, oat meal and pizza) I do 18/6 protocol 7 days a week. 40 lbs lost over three years. I never count a calorie. My blood tests at 53 are that of a 23 year old athelete. Great article.

  • Dormer

    Fasting every 3 days applies to mice. This program requires 5 days in humans.

  • Justagirl

    The Author writes

    You can also do the 5:2 protocol while you’re at it, which means to do a 24 hour fast two days a week (separated by at least one day)

  • David

    One wonders that if eating only two meals per day (during a 6-8 hour interval of time) is better than eating three, perhaps eating only one per day or none on certain days (e.g. the 5:2 plan) could have even stronger effects, as long as it’s sustainable and you’re able to get enough nutrients. This may be particularly true for specific benefits e.g. weight loss, or cognitive effects.

  • Paul

    I normally weigh just a bit more than 160 pounds. I tried a 4:3 diet where I ate unrestricted for four days a week and limited my diet to 600 calories on three days: Sunday, Tuesday and Thursday. My weight slowly dropped to 152 pounds over a period of 14 months. I noticed no particular improvement in health, cognition or fitness during that time. However, I had to quit when my weight got to its minimum because I began feeling weak, nearly to weak to walk. Now I do time restricted eating, using an 8 hour (or less some days) window for my meals, plus I fast for 3 to 5 days, every six months, as recommended by Dr. Valter Longo, to enhance my immune system. I seem to maintain my normal weight this way and feel fairly well on this plan.

  • D. W.

    Well written article with plenty of published research to back up your claims…however, how did you surmise that a 5:2 plan is the most optimal way to IF? Any studies, even case studies, to demonstrate this?

  • Wideman

    With the 5:2 protocol for fasting should the fasting days be two consecutive days or should there be a few days in between

  • Brett

    so this is saying: eat normal 5 days a week, but two days a week eat less than 700 calories total in either the early morning or evening… but consume nothing but water between the hours of 8am to 6pm?

    1. Joseph M. Cohen

      No, I updated post

  • Lorn

    Would eating fat during intermittent fasting be as beneficial (as bulletproof people espouse)?

    1. Joseph M. Cohen

      Protein and carb restriction have certain benefits, but it’s also calorie restriction in general.

  • Oskar

    “In a study involving mice, increased insulin resistance was observed in the intermittent fasting mice compared to mice following a normal eating pattern”

    Isn’t insulin resistance something we’d like to avoid? And the summary of the linked study was mostly about IF worsening the health of hypercholesterolemic mice although there was mentioned that regular field mice had opposite outcomes.

    1. Joseph M. Cohen


  • Mint

    People with circadian rhythm issues
    People who have neuroendocrine issues and glutamate excitotoxicity, although following my approach will minimize the down side

    those two i didnt understand!


    Love this thank you! Are the 7-800 calories net of exercise? (Burn 1000 cycling plus consume 800 =1800 calories) Or burn 1000 calories consume 800 = -200 deficit.

    1. Joseph M. Cohen

      700-800 is total

  • Leave a Reply

    Your email address will not be published. Required fields are marked *

    This site uses Akismet to reduce spam. Learn how your comment data is processed.